Impact Plants

HOW CAN I GROW AN EVERGREEN HEDGE RIGHT NEXT TO THE SEA

2011-12-14T03:14:00.000-08:00

Growing by the sea can have both advantages and disadvantages. Plants sensitive to cold conditions may be helped by a milder climate than that found inland where the moderating effect of the sea has no influence. On the other hand salt laden winds are a problem for very many plants and only a minority are well adapted to them.

Griselinia is a classic, and frequently very effective, evergreen hedging plant for coastal areas. It will form dense attractive hedges in areas which are never exposed to very cold winds. There are other evergreen hedges which might be suitable in areas which aren't exposed to very cold winds - varieties of Escallonia, Holly, Bay, Choisya, Cotoneaster, Euonymus, Hebe, Pittosporum, Pyracantha, Viburnum, and Leyland Cypress. In addition Holm Oak, Junipers and especially Pinus nigra might stand up to very cold winds. Much depends on whether you want a low, formal hedge or a larger, less restricted visual barrier, such as Pinus nigra would give. Holm Oak and Leyland Cypress might also provide this.

WHY HAS MY LEYLAND HEDGE DEVELOPED LARGE BROWN PATCHES AND WHAT CAN I DO ABOUT THEM?

2011-10-28T01:29:00.000-07:00

Problems with brown patches on Leyland Cypress hedges seem to be increasingly frequent. Hedges which had grown happily for many years develop brown areas which can vary from a few inches across to several feet. Hedge owners are then faced with a dilemma. Can the hedge be saved or improved or must it be removed entirely.

The Royal Horticultural Society (http://apps.rhs.org.uk/advicesearch/Profile.aspx?pid=132#top ) suggests that there are two major reasons why these patches might appear – attack by aphids and fungal diseases. Damage caused by aphids develops in late spring and summer and is found more often at the base of hedges though it can develop at any height. The browning can develop long after the aphids have left the foliage. The RHS suggest that spraying can be effective if the aphid attack is caught early and that some regrowth of new green shoots is possible. As a general rule however growth of new green shoots on brown conifers stems is slow if it happens at all.

Fungal disease is also a common cause of brown patches. Over enthusiastic hedge trimming, especially at times when a hedge is stressed, may increase the likelihood of die-back. They suggest that trimming in April, June and August is safer than in autumn. They especially suggest that you don't trim in hot or dry periods or in the autumn and that you never cut into old wood but only trim the outside growth. By old wood they mean thicker stems deeper into the body of the hedge. Feeding and mulching of the hedge in late winter, in preparation for spring growth, is recommended.

With an established hedge there may be nothing significant to be done to remove the brown patches and it could be necessary to take the plants out entirely. To replace the removed plants can be a difficult matter as the roots of an old hedge will be extensive and they will have removed most of the nutrients from the ground for quite an area around. Full removal of the stumps and replacement of the surrounding soil is the most likely way to provide a decent environment for a new hedge to grow. This might need the use of a mini-digger and is likely to involve professional landscapers. As replacements you should consider tough evergreen hedges such as Laurels, Portuguese Laurels or Western Red Cedar which would grow relatively quickly. Ivy screens are an option where an instant evergreen fencing/hedging solution is needed which will stay at around 2m high. Yews may also thrive and provide excellent formal hedges long into the future. All are less likely to suffer from the problems which Leyland Cypresses are prone to.

Garden Trees and UK Law

2011-08-17T07:03:00.000-07:00

We sometimes receive enquiries about the legal situation regarding trees in domestic gardens and try to give some basic guidance. The information given below is offered in good faith to cover some situations in the UK but we can't guarantee that it will apply in all situations. Before taking any of these matters further please check with your local authority or a bona fide legal adviser.

Q A neighbour's tree overhangs my garden, cuts off the light to my house and blocks my path. What can I do about it?

A The first thing to know is whether the tree is covered by a Tree Preservation Order or is in a Conservation Area.. Permission from the Council may be needed in either case to undertake work on the tree so start by contacting the Tree Officer from your local authority. In civil law you can take back to the boundary line any branches that overhang your property from trees not covered by these restrictions. This can be done without informing your neighbour or gaining their permission but it is always better to let them know in advance. In law the timber removed belongs to the owner of the tree and should be offered to them. If you think that a tree blocks off light to your house or garden without overhanging your property then the problem becomes more complicated and you may have to take legal advice after you have spoken to the owner of the tree.

Similar points apply to overhanging fruits which technically belong to the owner of the tree. However you have no right to insist that your neighbours clear up fallen leaves or fruit in your garden.

2 Q Do I need permission to cut down or prune a tree in my garden?

A Again you need to check whether the tree is covered by a Tree Preservation Order or is in a Conservation Area. Contact the Council Tree Officer to clarify this. You will also need permission from the landlord if you are in rented property. If you are in a newly built property trees in your garden may be covered by the original planning permission for up to five years so there may be restrictions as to what you can do.

3 Q My neighbour has a high evergreen hedge which is cutting out my light. Can I make him cut it down?

A The first thing to do of course is to discuss the options with the owner of the hedge. If this fails to produce the result you want then the local authority is empowered to adjudicate. You will need to approach them formally and to pay them a fee. They may dismiss the complaint or issue a formal notice of remediation to the hedge owner to remedy the situation. Usually this means a reduction of the height of the hedge to no less than 2 metres (about 6ft 6in). If the hedge owner doesn't carry out the work the Council can prosecute, issue a fine, and undertake the works themselves and recover costs. Information on this process is available from

http://www.communities.gov.uk/publications/planningandbuilding/overgardenhedge

http://www.communities.gov.uk/publications/planningandbuilding/highhedgescomplaining

4 Q How can I get a Tree Preservation Order made

A This is a legal process which is decided and implemented by your local authority Tree Officers.

5 Q My neighbour has started to cut down a tree. Is he allowed to do this?

A If the tree is not protected (see question 2 above) then he won't need permission unless -

a) the tree is on a joint boundary or access is needed to the adjoining property to undertake the works. Permission under civil law is then needed from the other party or

b) the tree is so large that the work, especially felling, poses dangers to land and property and would therefore require clearance under Health and Safety regulations.

6 Q What can I do if I see someone working on protected trees and I think that they may not have permission?

A Firstly don't take the law into your own hands but approach the owner or tradesperson

politely and ask them whether they know whether the tree is protected and whether they have approached the local authority for permission to work on it. If the situation remains amicable ask whether you can see the written answer from the Council officer. If you don't feel able to do this you can approach the Council tree officers directly to inform them about the situation. If it is out of work hours you should report the matter to the Council as soon as possible on a working day making as many notes of the details as possible. This might help if the Council decides to start a prosecution. You can also approach the police and ask to speak to the wildlife officer if you think that there may be danger to protected species or it is the bird nesting season.

Should I Be Watering My Trees After This Dry Spring

2011-06-07T01:50:00.000-07:00

This has been an exceptionally dry spring in most of the UK. Only the north west has received normal amounts of rain. It has followed a very cold winter and a recent prolonged windy period has itself caused extra drying. There are worries that the combination of extreme seasons may be of particular harm to larger plants which have been planted within the last couple of years. These may not yet have developed the extensive root systems which would see them through a drought and the result could be die-back or the death of the plants. A sign of the stress which the plant is suffering might be the loss of leaves or sections of the plant or, for fruiting trees, the loss of fruit. Remember that the rain showers of the recent weeks may not yet have penetrated far enough into the ground to reach lower roots.

If you are worried that these conditions might apply to your plants, or you see signs of stress, then now is the time to take action. Fruit trees in particular may need attention as fruit, which is mostly water anyway, will be swelling and may require more water than the tree can provide. Fruit trees may cast off a large percentage of their growing fruit to reduce the stress they are suffering. To counter this a regular application of a trickling hose to the soil surface around the trees will help. If this is not possible then a bucket, or watering can, of water applied regularly may have the same effect. Action now may prevent fruit fall, leaf loss or the death of a large plant.

Planting trees near to houses and walls

2011-03-29T05:03:00.000-07:00

It may be wise to consult your insurance company before you plant a large tree in your garden. Be aware however that they are likely to give a very conservatve reponse and that our towns and cities would have far fewer fine trees in them if insurance companies had been the arbiters of what to plant.

There is another way to look at this problem. In many countries street trees are planted into prepared planting pits along the sides of roads. These are effectively large sunken plantpots which allow space for tree roots to develop without interfering with buildings, drains or other services. If you are keen to plant a large tree into a space near to walls, buildings, or services it may be possible to create a pit. For large trees you would need a pit around 2m x 2m and 1m deep. This would have thick walls of blockwork or alternatively welded steel. You would be making an enormous container with drainage holes to prevent it turning into a sump or underground pool. It would be essential to ensure that the container can drain properly and so it is unlikely to work if the pit is dug into clay unless you can arrange good drainage through the clay and away.

In order to water the tree effectively and, almost as important, to allow air to the roots a perforated plastic tube around 50mm in diameter should be buried to the depth of the pit but with its inlet just above soil level. These are available from tree and landscape suppliers but you could improvise one from a length of drainage pipe.

If made well this should allow a tree to thrive in a limited space without danger to its surroundings.

I NEED A HIGH EVERGREEN HEDGE TO BLOCK OUT A VIEW. HOW SHOULD I DECIDE WHICH TYPE TO BUY?

2011-02-02T07:08:00.000-08:00

There are many varieties of plant which make excellent evergreen hedges. The first thing to bear in mind though in the UK is that neighbours and local authorities can object if boundary hedges are higher than 2m.

For many people the first plants which come to mind will be conifers. Leyland Cypress are infamous for making enormous hedges which can be a problem both for the owners and their neighbours. If clipped closely twice a year they can make excellent hedges but it is common to see Leylands which have grown enormous, very tall and very thick, or both, and which will never look good again. In addition they now often suffer from a disease which causes large brown patches. A similar plant, but one which is more attractive and has fragrant leaves, is Western Red Cedar. This will also grow away rapidly if not tightly controlled. Both of these types of conifer will grow in poor conditions such as thin soils or a degree of shade but they will also take most of the nutrients from the surrounding soils making it difficult to plant close to them. The best conifer hedges, and the most traditional, are undoubtedly Yews. These venerable plants have been used in formal gardens for centuries. They make close, dense hedges which can be clipped to shape. Their preference is for lighter, drier soils and they should not be considered for damp situations or heavy clay. They are slower growing than Leylands or Cedars but are readily available as large plants which will soon grow into each other. They are also more expensive.

There are broadleaved plants which make good hedges. Two varieties of laurels, the common laurel and Portuguese laurel, are frequently used. They both have large leaves which can look untidy after cutting – their edges tend to go brown for a while – but are tolerant of shade and a variety of soils. Portuguese laurels have neater leaves and can be used in shallow, chalky soils where common laurels may not thrive. Smaller leaved plants such as privet, Lonicera nitida and escallonia are commonly used in urban gardens. Privet will grow tall and is tolerant of most soils and situations although in the coldest regions it can lose it's leaves in winter. Lonicera nitida is quick growing and can be tightly clipped though it has a habit of leaning or even collapsing when tall. Of the many varieties of escallonia, which have the advantage of attractive flowers, the variety rubra Macrantha is probably the best for hedges and is particularly good near the seaside where it withstands salt-laden winds. In this situation Griselinia littoralis is also excellent. It clips well, grows fast and is salt tolerant. Box (Buxus sempervirens) makes an excellent hedge suitable for very close clipping and the smaller leaved box, Buxus microphylla, is also a good low hedge. Both are rather slow growing.

Many other evergreens will make quite good low hedges but would not be suitable for blocking out a view. There are good holly hedges, but often plants are gappy if not well grown and they may fill the garden with prickly dead leaves. Eleagnus, Euonymus, Pyracantha, Osmanthus, Bay, Berberis, Aucuba and Abelia will make good hedges under the right conditions. Ivy is available in the UK covering wire mesh panels 1.8m (6ft) high which can be used instead of fence panels to give thin evergreen screens.

Finally we should consider two cheap and effective plants which are not really evergreen but can be just as effective. Beech and hornbeam are very good hedging plants and will keep their brown leaves through the winter if trimmed in late summer. They can form hedges which make equally effective screens as genuine evergreens but they are native and tough.

ARE THERE PROBLEMS BUYING AND PLANTING LARGE PLANTS IN THE WINTERY WEATHER WE HAVE AT PRESENT?

2010-12-02T07:23:00.000-08:00

We sell large trees and hedges throughout the year but I have to face the fact that there are problems buying and selling in extreme weather like we have at present. There are obvious difficulties with transport butalso more subtle, long term problems with hardiness and survival of the more tender species. Last winter, which was tough for many people here in the UK, was even more extreme in parts of mainland Europe including countries where many of our plants are grown. How can we be sure that normally hardy plants which we buy and sell at this time of year will thrive. Basically I'm not sure we can and replacement of failed specimens appears to be the only answer.Last year parts of the Netherlands had more extreme weather than we had in the UK with temperatures falling much lower. One result was that some evergreens such as laurels, bought widely from Holland for hedging and screening, appeared fine when delivered in early spring but several of them dropped their leaves soon after and appeared completely dead. Customers buying these needed them replaced and we, and the nurseries who supplied them, were happy to arrange this. Of course we had to be satisfied the plant deaths were not the result of poor planting and aftercare. The landscapers who bought and planted these explained to their customers that they were bought in good faith and that it is not always possible to be sure from the appearance of plants bought after extreme weather that they are still thriving. Buying deciduous plants can also be difficult as trees and shrubs bought and planted in the winter may not show any obvious signs of death or distress until they fail to thrive in the spring.

Buying plants can be more difficult in extreme weather but what about looking after them and planting them. Advice usually depends of the kinds of plants bought. If you buy plants in containers such as pots or growing bags they are, providing they are hardy plants, able to survive for long periods out of the ground. Problems can be greater for evergreen plants as they need moisture throughout the year and protecting the roots from extended periods when their roots are frozen solid is very worthwhile. They need to be able to take up at least some moisture. Plants which are rootballed ( their roots are wrapped in hessian, or wire and hessian, which is put in the ground without unwrapping ) need to be placed away from drying winds but again these are usually capable of standing periods of extreme weather. Plants delivered barerooted need extra protection. If the ground is covered in snow or frozen so that they can't be planted on even a temporary basis, they may be better with their roots wrapped and stored out of direct wind.

Planting is never recommended when the ground is frozen or waterlogged. It's better to wait until conditions are less extreme before planting in the chosen place.

TREES ON WET LAND

2010-09-07T02:11:00.000-07:00

If your land is often wet and cannot easily be drained there are still plenty of options for planting trees. Firstly, there are species adapted to wet ground. Willows, Alders and Poplars are amongst the commonest but a good book (such as Hillier's Manual of Trees and Shrubs - ISBN 0-7153-9942-X) will give you lists to choose from. It will also give you an idea of how high your trees may grow or other conditions, such as strong winds, which they may tolerate. Red Alder, River Birch, Liquidamber, Black Gum, Caucasian Wingnut, Scarlet Willow, Corkscrew Willow, Chinese Swamp Cypress, Dawn Redwood, Pond Cypress and Swamp Cypress will tolerate or even enjoy permanent dampness. Many other trees may survive occasional flooding but their survival chances will be improved by planting them with their rootballs above ground level. They can be planted with more than half of their rootball above the surrounding ground level and soil can then be drawn up to cover the exposed roots. Better still they can be planted into a raised mound. As the roots grow into the mound they give long term stability to the tree. In addition fewer roots will be killed by the lack of air which flooding creates and the tree is more likely to thrive. This technique allows a greater range of trees to be tried -for instance the Common Silver Birch, Hawthorn, Pin Oak , Rowan and Sitka Spruce. Native Oak (Quercus robur) and Ash will also tolerate some periods of dampness.

I HAVE BOUGHT SOME LARGE HEDGING PLANTS AND TREES ONLINE. HOW SHOULD I LOOK AFTER THEM WHEN THEY ARRIVE?

2010-07-30T03:11:00.000-07:00

How to look after new plants which are delivered to you will depend on the type of plants and the time of year. It is essential for all plants in containers, and for all trees and hedges facing their first year in a garden, that their roots are not allowed to dry out. Judging this is not however all that easy. Large plants standing in containers prior to planting may need a lot of water during dry periods in the spring, summer or autumn. If they are from a reputable grower and the compost is of good quality they can be watered at the top of the pot until water starts to come out of the bottom. In very dry weather this may be needed every day but in general will not need to be more frequent. Once planted, watering during the first year, or even two years, will be needed in dry spells.

It is generally easy to spot stress in broad leaved plants – the leaves will start to curl and wilt. For conifers, and evergreens such as Laurels, it may not be so easy to spot these signs and by the time signs of dryness are obvious the plant may be in difficulties. For these plants it is even more vital to keep plants, both in containers and in the ground, well watered. Brown patches on conifers in particular can be difficult or impossible to reverse. Parts of a plant, or even the whole plant, may be permanently lost.

During winter months, especially once the leaves have fallen from deciduous trees, watering problems become less severe. The air is cooler and plants which have lost their leaves lose little moisture. Watering is not generally needed. There can be a problem for evergreens in the coldest months if the containers freeze solid for several days or weeks. This is because evergreen plants can still lose moisture through their leaves in the winter and this needs to be replaced by their roots. Their roots, frozen solid in pots, may be unable to provide this. In the coldest regions it may therefore be useful to find ways to prevent long-term freezing of the pots by moving them to warmer areas or insulating them with bubble wrap or straw.

Plants bought with the intention of planting them out will generally appreciate being planted as quickly after arrival as possible. Weather conditions may not allow this in the first few days. For instance the ground may be frozen solid or waterlogged by rain. Other approaches are needed. Many large hedge and tree plants provided in the winter months are rootballed. This means they have been lifted by machine and their roots have been wrapped in hessian sacking. This gives a ball of roots and soil which can be planted without removing the wrapping. The whole rootball can be planted with the top of the hessian close to ground level. If plants arrive when weather conditions prevent planting they can be left for some time. Plants in rootballs can be left away from drying or freezing winds until a suitable time arrives and, indeed, are sometimes left several weeks in the winter without suffering harm. When a suitable time for planting does arrive it is still important to ensure that planting holes or trenches do not fill with water and that the plants do not rock in the wind. On clay soils especially it is vital not to dig holes which fill with water leaving a plant's roots effectively in a pool. And in the winter, when winds are generally stronger, plants need securing so that they don't rock in the wind, loosening the roots and destroying their intimate contact with the surrounding soil. A solid stake, or a rail attached to sturdy posts, and efficient tying should achieve this.

SHOULD I REMOVE IVY FROM MY GARDEN TREES

2010-05-11T01:39:00.000-07:00

In Britain there is always a debate about the desirability of allowing ivy to grow on trees. Many people consider that it is harmful to allow it or, at best, that it spoils their appearance.

Ivy is Britain's only native climbing evergreen and is very widespread. It can tolerate deep shade. If it were an exotic plant imported from far away it might be widely considered a great boon for gardeners. As it is, we frequently think of it as a weed. Is it actively harmful? It can of course be annoying, invading shady borders where tidy gardeners might not want it. It can radically change the appearance of a tree, removing the beauty of a clear trunk or its classic appearance. Long term experiments have shown however that the effect on the growth of a tree of allowing free rein to ivy is negligible. Only aged trees are likely to be affected by the reduction of light caused by the ivy leaves or the greater profile offered to the wind. Unlike parasitic mistletoe, ivy does not take anything from trees as it grows, it merely uses them as a means of support. In the process it provides a wonderful habitat for birds to nest, insects and invertebrates to live and bats to roost. Flowering late in the year ivy gives pollen and nectar at a time when there is little else around. These flowers produce berries in March and April which are an excellent food source for thrushes, pigeons, starlings and overwintering blackcaps.

Many people will however decide that the appearance of a cherished tree is being spoiled by ivy and will decide to remove it. This is is often easily done but keep in mind that cutting the stems of a large ivy plant on a tree will result in brown unsightly remains and these may take a year or two to fully remove. If the ivy is removed during the spring or summer it is important to realise that this may disturb nesting birds or roosting bats, both of which activities are against the law. If you still want to remove your mature ivy from a trunk it is best done in early autumn when these problems are less likely to arise.

In the end the decision to remove ivy from your trees is probably more of a personal matter. It is likely to be about neatness or the pleasure derived from seeing the uncluttered tree. In their natural situations trees and ivy, at least in Britain, have achieved a balance which provides a very valuable habitat.

HOW TO PLANT A HEDGE

2010-02-12T04:20:00.000-08:00

Hedges come in many shapes and sizes so planting them can be just as varied. So let's start with the simplest. In the UK our landscape is crossed by tens of thousand of miles of hedges going back hundreds of years – or even longer. The majority of these were planted using very small plants, which we now call whips, and the variety of plants in the hedges has increased with time. Indeed it's possible to estimate the age of a hedge by measuring the number of different species in the hedge for every hundred metres.

The cheapest and easiest way to plant a modern hedge is to buy whips. Whips are small trees which normally have side branches, depending on the species. They are at least 2-3 years old and have been transplanted to ensure a compact and fibrous root system for successful planting. Nevertheless when you buy them they will probably look to you like sticks with a small bunch of roots on the end. They are purchased and planted in winter when the leaves are off the trees and don't look impressive at all. They are very cheap however and will soon leap into growth in the spring.

Whips can be bought to suit your local conditions. Sandy soil mixes, clay mixes and chalky soil

mixes are available and you can make up your own mixtures to suit your conditions and wishes.

You will not find evergreen plants as whips as they do not lose their leaves or become dormant in

the winter. If you want Holly or other evergreens you will have to buy them grown in small pots and they will be a little more expensive.

To plant whips you will first have to clear the ground. Small trees do not like to compete with

weeds and grasses for the nutrients and moisture in the ground. You can get round this clearing to some extent with a mulch made of a modern landscape material which will suppress the weeds and keep the roots of these small plants moister in their first, critical growing season. If you have cleared the weeds then a mulch of bark or other natural material may fulfil this function just as well. The whips are usually planted at 5 plants per metre in two staggered rows about 30cm apart. Usually there is no need to feed these tough native species but it is vital to ensure that they don't succumb to drought in their first couple of growing seasons. A mulch will help but some watering may be needed.

New plants often need protection from deer and rabbits so cheap tubes and coils of plastic are

readily available to act as guards until the plants are large enough to look after themselves.

Hedges can be planted in several other forms which give more maturity from the start. These vary from larger individual plants in pots, through plants in troughs which are starting to grow together, to fully mature hedges knitted together and planted by professionals to give a truly instant effect. Within this great range there are all sorts of possibilities. You can buy large plants up to the size of small trees which will grow into each other to form a tall hedge or screen. These are available as trimmed plants or even as squared off units which will fit next to each other to give a continuous hedge almost from day one. These are especially effective when they are evergreens (though please note that, within the UK, neighbours and local authorities can object to evergreen hedges over 2m high and require you to cut them back). When you are dealing with these plants at large sizes be aware that they may be very heavy and difficult to handle, move and plant. Professional help and even machinery may be needed.

To prepare the ground for larger plants, or troughs with several plants in them, will be more

complicated than for whips. Whips can often be planted simply by making a slit in the soil with a

spade, placing the roots of the plant in the ground and firming them in with the heel. Larger plants and especially those in troughs or with enormous rootballs, need trenches or large holes. This can cause problems in heavy clay soils where a hole dug in the clay can become waterlogged and act effectively as a small pond. This would give very bad conditions for root growth so drainage at the bottom of the hole is essential before planting.

Rootballed plants come with their roots wrapped in hessian ready to be placed straight in the ground without unwrapping. These and plants in containers need firm ground around the roots to stop them swaying in the wind – a process which stops the roots from growing into close contact with the surrounding soil. In windy situations, and especially for large plants and evergreens, it may be necessary to restrict the movement of the plants by tying them to wires attached to tensioning bolts and braced fenceposts. This however is usually a job for professionals, not for someone attempting the job for the first time.

Feeding plants with slow release fertiliser is worthwhile but the number one essential is to avoid the roots of your new hedge drying out completely during the first year or two. An automatic watering system is the best way of ensuring this but, at any rate, vigilance and an effective back-up system for watering are vital.

HOW CAN I CREATE A RAISED TREE SCREEN?

2010-01-12T01:13:00.000-08:00

There are many situations where a raised screen of trees is useful. For instance, if you have an attractive wall which is, say, 6ft high and you wish to screen out a distant view above it without obscuring the wall you might like to use trees which have been grown as standards or high panels. What however do these different terms mean and how can these plants be used.

Standard trees are grown with a bare trunk around 6ft high (occasionally they are slightly higher at 2m and half standards are also available with shorter trunks). These bare trunks are usually easy to keep bare and you can allow the tops of the trees to grow to suit your needs. However you will need to buy trees to suit the situation. For instance a row of Birch trees may eventually grow to 45ft in good growing conditions and be 20ft across the crown but this could take many years. You would have to decide when you plant them just how far apart they should be. They will also be deciduous so the leaves will fall in winter and they will not form the same screen. There are alternatives however which will make it easier to provide a quicker and more controllable screen.

Both deciduous and evergreen standard trees, such as Holm Oaks (Quercus ilex), Laurels or the shorter Photinias, can be bought as standards and tightly clipped to create a screen limited to the size you want. Left to themselves Holm Oaks would grow as large as any Oak tree but clipped they can be kept to the size which suits you. This however requires a clip at least once a year. There are nurseries which sell a range of deciduous and evergreen trees clipped as high panels, that is bare trunks with a rectangular panel of branches carefully trained to shape on top of them. These can be planted next to each other to give an instant high screen. More decorative, but less effective as screens, are pleached trees where the high panel is trained along horizontal wires. Similarly espaliered fruit trees can be bought ready trained to give horizontal tiers of fruiting branches but these are usually on much shorter trunks for ease of picking and are less effective as screens. They are however a very effective way of dividing a garden into sections being both productive and extremely attractive.

To achieve the sort of high screens you want you will have to work out the overall width of the screen and the height which it needs to achieve. Then there is the qustion of tree variety. Do you want evergreen or will deciduous do (deciduous is often cheaper) and do you require anything else from the tree such as attractive foliage or flowers. Finally will the trees thrive in your garden conditions or will soil and drainage problems compromise their development. You will probably need to refer to a textbook or speak to an expert to answer these questions. A site visit may also be needed.

I HAVE SEVERAL ACRES I WOULD LIKE TO PLANT WITH LARGE TREES. HOW SHOULD I START PLANTING TO ACHIEVE FAST RESULTS WITHOUT SPENDING A FORTUNE?

2009-10-19T02:31:00.000-07:00

Many people want to create small woodlands or simply make their land more attractive but don't want to wait too long for results. In the past the reasons for planting woods were often different from today's reasons - for instance planting to produce valuable timber or cover for game. These days the reasons are more likely to be aesthetic as there is a general understanding that huge areas of woodland have been lost and the countryside looks poorer as a result. Landowners may also be inspired by the valuable habitats which woodlands can provide or the future use of managed woodlands as sources of biofuel.

The first place to start when considering planting a woodland is to try to ensure that the trees planted suit your environment. For residents of the UK it is straightforward to discover what is native to your area by entering the first three digits of your postcode into the appropriate part of the website www.nhm.ac.uk/nature-online/life/plants-fungi/postcode-plants which is a national database provided by the Natural History Museum. This excellent resource will tell you all the native plants, not just the trees, for your local area. You should then look at any particular problems which your land may provide for a growing tree. These would principally be problems of drainage, soil type and exposure. All three of these could vary within a very small area so that very damp or dry patches, extremely windy areas or local soil problems might produce situations which may not be obvious from the database. The soil for instance may have been compacted by building machinery or polluted by previous use. If any of these problems seem likely than a site visit from an expert may be necessary and soil samples may need to be taken and analysed. However if your site is fairly typical of your neighbourhood the database will give you a good idea of where to start in choosing trees (or for that matter hedges and smaller plants).

There are several varieties of trees known for the speed with which they grow. Poplars, Willows and Eucalyptus are amongst the commonest. Indeed Poplars are the fastest growing source of hardwood in the UK. These varieties may not give you the end result which you need especially if you have a vision of stately trees with large spreading crowns lasting through the centuries. If you imagine your land covered in large Oaks, Beeches, Ashes and the like you will need to take a longer term view. Planting a fast growing species to give an early effect, with these larger species growing more slowly next to them, one day to take over from them and shade them out, may be your best approach. Willow, Alder, Poplar, Sorbus (such as Rowans) and Birch will give you the fast growing "nursery crop" amongst which the giant trees of the future can develop. Willows and some Poplars can sometimes be grown successfully simply by sticking suitable branches straight into damp ground, though they will need protection from rabbits and deer.

Buying and planting these larger trees is not entirely straightforward as there are several options. Mature trees, up to 9m (30ft) tall, can be bought, transported and planted by experts but this is a pricey business. You will be spending thousands per tree and access for large machines will be necessary. Trees smaller than this can also be bought and planted in a similar way but sometimes they can also be dug up and moved using tree spades where suitable specimens are available locally. Moving trees can work out far cheaper than buying new, purpose grown specimens.

At the other end of the spectrum trees can easily and cheaply be bought as bare-rooted plants. As the name suggests these are smaller trees, usually up to around 3m (10ft) high, which have been dug up during late autumn and winter when their leaves have fallen off and they are dormant, and are sold with no soil attached to their roots. They can be a very cheap way to buy trees and they usually establish well but, despite the fact that they come into leaf in the following spring and appear healthyl, they may sit still in your soil for several years without making much growth. They are building up their reserves and growing roots during this time. It may be very frustrating to wait for them to start back into serious growth after several years.

More expensive, though often very reasonably priced, are rootballed trees. These are grown in open ground and are prepared for movement in advance of digging them up. When they are lifted their roots are surrounded by some of the soil which they have grown in and are then wrapped in hessian. They are transported like this and the tree, complete with rootball and hessian bag, is planted into the new ground. Over time the bag rots and the trees strart back into growth with less of the disturbance which bare-rooted trees have suffered. They generally establish and grow more effectively than bare-rooted specimens.

The final option is to plant more expensive trees grown in containers. The art of growing trees in pots and bags has advanced greatly in recent years as our understanding of the needs of trees, and especially their roots, has moved on. Container-grown trees up to a considerable size can now be bought though it becomes difficult, and a little dangerous, to plant by hand trees in containers larger than around 70-90litres. Back injuries can easily result. Plants larger than these sizes need to be moved and planted by machine. Having spent more on these container-grown plants, whose chances of survival and speed of growth are likely to be greater, it is well worth getting professionals to plant them and look after them. If however you wish to plant them yourself you can usually buy container grown trees around 3-4m high for around £75-£100. They can be delivered to you and can sit happily in their pots for a time, as long as you look after their needs for water and support, whilst you wait for a suitable time to plant them.

With all of these trees aftercare and planting will matter even more than choosing the right varieties. A dry period in the years before a tree has settled in can kill off any tree and poor planting can produce all sorts of problems.

CONTRACTORS HAVE RECENTLY DAMAGED A MATURE TREE IN MY GARDEN. IS IT POSSIBLE TO REPLACE IT?

2009-10-02T03:46:00.000-07:00

22. CONTRACTORS HAVE RECENTLY DAMAGED A MATURE TREE IN MY GARDEN. IS IT POSSIBLE TO REPLACE IT?

It is unfortunately a fairly common experience for builders and contractors to work too close to mature trees and not to understand how much damage can be done. A mature tree may have developed a very wide spread of roots and the tree will be feeding using the small roots at the edge of this spread. Damage to a large part of these can result in severe damage and die-back. Damage to bark, or as a result of piling soil against the trunk ( something which is dangerous for almost any variety of tree) can result in death or an ailing tree. It is not uncommon however for the contractors to have a legal duty to replace damaged mature trees and this at least can provide a reasonable budget to take on the work. Of course if the contractor's appear to have deliberately endangered a tree in order to facilitate their works the local authority may become involved and there may be a more serious legal outcome.

What is then possible as a replacement for a mature tree? Trees up to 10m, 30ft, high can be moved and planted but this of course is not a small undertaking. Often these trees will have been grown far away from your garden and will have to be moved a large distance by special transport. Access to the garden for large machinery will be necessary to bring the tree in, to excavate the planting pit and to remove the soil. The ground will have to be free of underground services and will need to be suitable for the chosen species. Water tables and drainage will need to be suitable. Between the largest trees which can be planted and the small ones available from a garden centre is a range of trees of intermediate size and price. In addition it is sometimes easier and cheaper to move a semi mature tree from a location closer at hand as an alternative to buying a new tree. Tree spades mounted on the back of trucks are able to dig, remove and replant surprisingly large specimens.

Finally, and vitally, it is important to have a professional to keep an eye on a newly planted tree and to advise on aftercare. It would be very frustrating to plant something so impressive and expensive only to have it die soon after.

CAN I PLANT A MATURE TREE IN MY GARDEN AND, IF SO, WHAT IS THE LARGEST POSSIBLE?

2009-09-17T01:51:00.000-07:00

In theory it is possible to plant large trees up to the size of fully grown, mature trees but in practice there are many restraints on what can be done. Nurseries in Britain and Europe grow enormous trees, up to 9m (30ft) high and with trunks 60cm (2ft) in circumference. In addition it is sometimes possible to move fairly mature trees using tree spades but often the trees will need preparing well in advance of the move. Moving any of these into a garden and planting them is a skilled and exceptional activity.

Access to most gardens is a problem. Heavy equipment is needed to move and plant mature trees and to remove the spoil which large rootballs produce. In addition the ground must be free of underground services and the water table must be suitable for the particular variety of tree. As the tree would have a large canopy vulnerable to movement by strong winds it would need specialist guying either by cables or by ground anchors.

The price of planting a mature tree is, of course, likely to be large both because of the long period of care needed to raise it and because of the expense of moving and planting it. In addition skilled aftercare is needed to ensure that the signs of distress in a tree are noticed before a situation becomes critical and the tree dies. Despite that it is a fairly cheap and straightforward job to plant trees up to around 4-6metres (13-20ft) high which are grown in large containers. These are grown in very large numbers by nurseries and can often be moved and planted by a couple of strong and skilled people. Of course they will also need proper aftercare to maximise their chances of survival.

IS IT A RISK TO USE LEYLAND CYPRESS FOR HEDGING ?

2009-01-13T03:25:00.000-08:00

There is always a lot of fuss about Leyland Cypress hedges. They have a reputation for being uncontrollable, for creating disputes between neighbours, for being ugly and, recently, for being disease prone. There are elements of truth in all these accusations but, set against these, it is quite possible to create beautiful Leyland hedges which are excellent screens.
The Leyland Cypress ( Cupressocyparis Leylandii is its Latin name) is a cross between two other species of conifer and is a classic example of hybrid vigour. It is a very fast growing plant, indeed the fastest evergreen with the exception of some Eucalyptus species. Even in poor conditions, such as thin chalky conditions and exposure to coastal winds, it is capable of decent growth. It can even tolerate a certain amount of shade. These benefits however can result in several problems. The roots of such vigorous plants can remove much of the moisture and many of the nutrients from the surrounding soil (on your own side of a hedge as well as your neighbour's) and so it can be difficult to grow anything near to a Leyland hedge. The primary problem however results from the vigour of its growth. A healthy Leyland Cypress can make several feet of growth a year. To contain it as a hedge needs ideally three sessions of trimming a year, in late spring, summer and early autumn. This is partly because it grows so fast but also because it will not grow again from the older, brown wood. Only the fresh green growth can be clipped effectively and this is at the end of all the branches. It is however possible to maintain a decent, though not perfect, hedge by twice yearly clipping. Anything less and gaps will start to appear at the bottom of the plants which will then look less attractive and stop working so well as a hedge.
Leylands have also frequently been used as screening. They are easily capable of forming a dense line of trees 15metres (50ft) high in reasonable conditions of soil and exposure. As with hedges, this can cause difficulties with neighbours and local authorities who may resent their overbearing effects and the loss of light and view which results. There have been many disputes between neighbours in the UK, several resuting in expensive law suits. The result has been legislation so that it is now possible for Councils to require any evergreen boundary hedge or screen to be reduced to 2m high.
Disease of Leyland Cypress have become increasingly common recently. Large brown areas in closely clipped hedges are an increasingly familiar site. In Britain the Royal Horticultural Society has carried out research into the problem (http://www.rhs.org.uk/Learning/Research/Projects/cypressdieback.htm) and in addition several bodies in the US have reported widespread occurance of Canker diseases. It is worth remembering that there are several alternatives to Leylands which, though less vigorous, make very good substitutes. Western Red Cedar (Thuja plicata), Lawson Cypress (Chamaecyparis lawsoniana) and Yew (Taxus baccata) may substitute well depending on the situation. In addition there are many non-coniferous evergreen hedges such as Laurel (Prunus laurocerasus) which thrive in similar conditions to Leylands.
To answer the original question, if I were to need a dense, evergreen hedge for my own garden I would choose one of the alternatives which are a little less vigorous or subject to disease. Having said that it is often possible to buy Leylands very cheaply.

FRUIT TREES FOR A SMALL GARDEN

2008-11-19T06:18:00.000-08:00

November and the months until March are the perfect time to plant fruit trees. Now that the leaves are off the trees, and the ground is not too cold, roots can establish themselves without any burden of feeding the tree. And in northern latitudes fruit trees are all deciduous, they lose their leaves in the winter.
Why plant fruit trees? Apart from the fact that many are very beautiful they are also extremely useful and help us to make our personal contribution to reducing climate change. Fruit, or for that matter vegetables, grown on our own piece of land reduce CO2 emissions. Avoiding delivery from far flung orchards or distant countries means no use of oil and no greenhouse gases.
In my own small garden the fruit tree of most importance is my Bramley apple. This is large enough to sit under in the summer, provide wonderful blossom in spring and a large and reliable crop of cooking apples each autumn. All winter I can watch birds moving onto it and through it to find a seemingly inexhaustible supply of food. What more could anyone ask from a single tree?
The range of fruit trees suitable for a garden is enormous. Most types of fruit, be they apples, pears, cherries, plums, damsons or gages have been grafted onto rootstocks to control their heights. This is a process where the top of the tree, above the graft, is the variety you want for its fruit but the bottom, below the graft, has been chosen for its vigour. The same variety, a Bramley apple for instance, may be available on very dwarf, dwarf, semi dwarf, semi vigorous or vigorous rootstock allowing you to choose the one which suits your garden best. In addition there are trees trained in the nursery to give different shapes such as cordons, espaliers, fans, stepovers and ballerinas. Cordons, fans and espaliers are trained flat to give small trees useful as a hedge or trained on a wall. Stepovers are so low that you can literally edge a garden bed with them and ballerinas give tall thin trees. Whichever form you choose is likely to be available in a huge range of apples. The other fruit, pears etc., are also likely to be available in a considerable number of varieties. So how would you choose the type of fruit to suit you?
This of course is a very personal matter. To consider only apples, there are lots of factors, starting with taste. This is entirely a personal matter but such issues as time of fruiting, ease of growing (some varieties are far more fussy and may need lots of spraying to produce decent crops - anathema to the organic gardener), whether dessert or cooking or both, ease of storage and pollination group should be considered. Get these wrong and you may have plenty of years to regret your mistake.
The best place to start is with a gardening book and one or more catalogues. There are many reliable nurseries with free catalogues of fruit trees which have been developed from ancient times to the present. But before you start looking at them you would be well advised to think about which varieties taste best. Then the finished size of the tree and lastly the pollination group. Some trees are self pollinating but most will need another tree flowering at the same time if they are to produce fruit. Some indeed, such as my Bramley, need two other pollinators flowering at the same time and these would usually have to be within around 100metres of my tree for the bees to travel between them. In towns or near orchards this is rarely a problem but with more remote gardens you may have to plant more than one tree to get decent amounts of fruit. Again a good book and a decent catalogue will help you out here.
After you have planted your tree don't expect a crop for the first year. If it produces a small one you should probably remove it as soon as you see the fruit set and leave the tree to gather its strength during that first crucial year. Water it well in dry spells during the first couple of summers and get ready to wrestle with the joys of pruning. It is quite possible to get crops without pruning but better crops produced more frequently, ie yearly instead of every two years, are more likely if you learn the beginnings of the art.I would always recommend referring to the Royal Horticultural Society, www.rhs.org.uk, for books and information on the subject.
Fruit tree catalogues in the UK can be obtained from www.frankmatthews.com or www.kenmuir.co.uk. Googling will produce very many more fruit nursery addresses.

CHOOSING A SHADE TREE FOR A SMALL GARDEN

2008-11-10T07:51:00.000-08:00

There are many trees suitable for providing shade. In my own garden a Bramley apple does the job very well but a Betula (Birch) would also do. A gently weeping Prunus (flowering Cherry) such as Shirotae - also known as Mount Fuji - would also be good but the roots are shallow and might be a problem if you are planting into a lawn. Sometimes the roots break the surface of the grass and make mowing more difficult. The amount of shade given by birch may be slightly less than for apple or cherry as the canopies of birch are lighter. This can be an advantage if you wish to plant into a lawn as it allows some growth of more shade-tolerant grasses.

All these trees are quite small and suitable for small gardens. The Bramley apple would need to be grown on a more vigorous rootstock so that you get the height and can walk underneath. You would need to make it clear when you buy one of these trees that you want one with enough clear stem to allow walking, or at least sitting, beneath it.

SHOULD I REMOVE THE IVY FROM A TREE IN MY GARDEN?

2008-11-06T03:02:00.000-08:00

There has always been a lot of controversy about the effect of Ivy on trees and whether it is a good idea to remove it or not. In the end your decision may depend on what you want from your tree - a classic uncluttered shape or a wildlife habitat and a more natural, woodland appearance.

Ivy is a native, evergreen climber able to thrive in very low light levels such as often exist on the woodland floor or underneath the canopy of a tree. It uses a tree as a means of support, a way of climbing from the darkness at the ground to the relatively higher light levels at the top of trees. When it arrives there it changes form and starts to produce differently shaped leaves as well as flowers and seeds. In the process it does not generally harm a healthy tree but may contribute towards removing light from the leaves of an old or dying tree. In addition some trees with lighter canopies, such as Ash, which let more light through may support larger Ivy plants but these are not expected to shorten the life of the tree. They may however make it more top heavy and likely to fall in a storm or they may disguise damage to the trunk or branches of a tree making it more dangerous. In woodland situations this may not matter but in private gardens, in parks or on roadsides consideration may need to be given to this. In addition you may feel that a tree covered in ivy does not look as good as one without.

Before taking the decision to remove Ivy from your tree however please consider that it creates an excellent wildlife habitat. As well as providing cover and food for a huge range of invertebrates (insects, spiders etc) it can give excellent roosting places to birds and bats, overwintering niches for butterflies and moths and, of course, nesting places for a range of birds.

if you decide to remove your Ivy it is generally done by cutting the plants low down. They rely entirely on their roots in the ground for nutrition, they do not take any from the tree, and so cutting the stems will kill the plant above. It will go dry and brown with time and can more easily be removed from the support of the tree.

To sum up, the decision on whether to remove the ivy will depend on what you want from your tree. If you want it for its form rather than its value as a habitat you may decide to remove the Ivy. In a woodland setting the choice is usually easier as the form of a tree grown in the relative open space of a park or garden is rarely achieved and you can appreciate the tree for its role in the woodland ecosystem.

CHOOSING NATIVE HEDGE PLANTS

2008-10-23T02:57:00.000-07:00

The correct mix will depend on your soil and site conditions and varies around the country and from site to site. The tableabove may be of help to you.

Hedging mixes are often around 50% hawthorn with the other half made from a mix of plants suitable to the conditions. You can see from the table however that hawthorn is not suited to wet or shady conditions. For these sites it may be better to use a large percentage of blackthorn. It is often a good idea to look at the hedging which thrives in your neighbourhood to see which plants are likely to do best.

2008-10-23T02:21:00.000-07:00

STAKING A TREE

2008-10-23T02:15:00.000-07:00

For very large trees, say those over 30cm girth (girth is the circumference one metre above the ground for a single-stemmed tree), special staking methods may be needed which can only be undertaken by professionals. For smaller trees however it is usually practical to undertake staking oneself. The basic intention is to stop the root system of the plant from moving in the wind whilst allowing the trunk to flex. It is also important to prevent the roots from being broken by the stakes during planting.

One modern way to approach staking is to think of the stem and branches of a tree in a similar way to the muscles of an animal's body - they are both strengthened by use. Thus allowing a tree to move in the wind without allowing the roots to move is likely to create a stronger tree in the long term. For trees with clear stems in situations of normal wind exposure a tree should be staked with a single stake driven in at 45degrees to the vertical and crossing the tree trunk about 450mm or 18inches above the ground. The stake should be driven in outside the rootball. A rubber tree tie should be tied round the tree and attached to the stake and a rubber cushion placed between the tree and the tree tie. These ties will need to be inspected each year and loosened as the tree grows.

In very windy siuations or for larger trees, say greater than 20cm girth, two short stakes with a wooden cross piece are best used. The cross piece has a rubber cushion attached between it and the tree and rubber tries are used to bind the tree to the cushion.

Very large trees may need ground anchors, or bracing using wires attached to the branches of the tree, but these are more jobs for professionals.

WHAT DO THE SIZES OF TREES LISTED IN CATALOGUES MEAN?

2008-10-23T02:00:00.000-07:00

Trees in the UK are usually listed by trunk size and by size of container. For instance a tree listed as a 12-14 is a tree with a single stem. The girth (circumference of the stem measured 1metre above the ground level) is in the the range 12-14cms. This girth is about three times the diameter at this point. By happy coincidence, for quite a lot of these standard trees (a standard tree has a clear stem up to at least 1.8metres or 6ft with a formed head above) the height of the tree in feet is close to the girth in centimetres. So a 12-14cm girth tree is likely to have a height of around 12-14 feet. Of course this is not an absolute rule.

Sometimes trees are sold with several stems (called multi-stemmed) and these usually have an overall height listed in a catalogue instead of a girth.

Pot sizes are often given but it may be hard to imagine them. Start with the information that a standard bucket is around 10 litres. Trees in pots up to sizes of about 50 litres can often be moved by one strong person and up to around 75litres by two people. Large trees in pots bigger than this will usually need machinery to move, lift and plant them and may weigh a lot. For instance a specimen tree in a pot of 350litres may weigh in the range of 350kg.

To give some idea of pot sizes, a 70litre pot will usually be around 45cms high and 50cms diameter and a 250litre pot may be 65cms high and 70cms diameter.

CHOOSING A HEDGE

2008-10-22T02:42:00.000-07:00

Hedges are part of our landscape and part of our gardens. We use them to give us privacy, to mark out boundaries, to keep animals in or out, and to provide habitats for wildlife. Sometimes we want them to frame a view, hide an eyesore or form a backdrop to our planting.. They may also form windbreaks, cut down noise or keep out unwanted intruders. For all these purposes it is worth planting the right varieties for your conditions or use. Plant the wrong hedge and you may have years to consider your mistake and more years to put it right.

There is a large variety of different plants suitable for hedging. Below we give a few suggestions about the basics.

FORMAL AND EVERGREEN HEDGES

Although an established deciduous hedge can be an effective screen and windbreak, evergreens are often faster and more complete. They tend to look more formal and give a better backdrop to planting displays.

Conifers such as Leyland Cypress, Lawson Cypress and Western Red Cedar can grow quickly and make a very dense and uniform screen. Although Yew is slower it makes probably the best formal hedge and can be cut to almost any shape. All parts of it except the red of the fruits are poisonous so it should never be planted where animals graze. Evergreen hedges over 2m high may be subject to objections in the United Kingdom by neighbours and the local authority who may make you reduce their height.

Other evergreens. Box are classic hedging and edging plants more appropriate for lower hedges than are conifers. Holly, Eleagnus, Euonymus, Laurel, Aucuba, Berberis, Bay, Privet, Pyracantha,Griselinia, Viburnum tinus and Lonicera nitida are also very useful and tough though they suit formal clipping to different degrees. Other shrubby plants such as Choisya, Rosemary, Lavender, Osmanthus, Pittosporum, Hebes, Escallonia, Cotoneaster and Abelia may be used for less formal hedging or for lower hedges. They will need to be fitted well to the particular conditions.

DECIDUOUS HEDGES

Gardeners have a large range of woody plants suitable for mixed or single species hedges. We may wish to create many effects- successive flowers, intruder proof thorns, a wildlife habitat, fruits etc. All plants have preferences in the conditions in which they thrive. They may prefer sunny or shady, wet or dry, limy or acid, light soil or heavy, exposed or sheltered. Often they can be left informal (not clipped too rigidly) but most hedges will grow more densely and be more effective barriers if they are clipped at least once a year. Amongst the more effective deciduous hedging plants are Beech, Hornbeam, Forsythia, Ribes (Flowering Currant), Elder, Willow, Blackthorn, Hawthorn, Philadelphus, Fuchsia, Dogwood and Flowering Quince. Many of these can be combined with each other and with evergreens.

Country hedges. Landowners and farmers are encouraged by the Government to plant native hedges in keeping with local traditions. In some cases Countryside Stewardship grants are available for this. They usually recommend at least five local species should be in the hedge with no more than 50% of any one. Hawthorn is usually significant in plantings, depending on conditions. Blackthorn, Field Maple, Hazel, Holly, and Dog Rose are also frequent. With time, of course, other native species will find their own way in.

SCREENS AND "FEDGES"

In smaller gardens the width available for a hedge might be very limited. Under these conditions there are various options, "Fedges" are a combination of fence and hedge and may be as simple as a trellis with plants growing through it. Some are available as instant hedging using, for example, ivy grown densely on trellis panels within troughs known as living green screens or ivy panels. These can be installed immediately on to hard surfaces such as paving and, provided that they are effectively watered, will give long lasting effects. Narrow screens can also be formed by bamboos provided that their roots are restricted by effective barriers to prevent them spreading out of control. Phyllostachis and Fargesia species can be excellent for this purpose.

Where larger screens are needed trees can be planted further apart and allowed to grow more freely into each other. Poplars would be a classic example of this. For more formal situations pleaching produces effective screens by weaving the branches of trees into each other. Often the tree trunks are left clear to, say six feet, leaving a line of sight beneath. Limes, Hornbeams, Beech and fruit trees are commonly treated in this way.

HEDGES FOR SPECIAL SITUATIONS.

It is usually a good idea to check the varieties of plants doing well locally in similar situations. For situations where there are salt-laden, high winds Berberis darwinii, Cotoneaster, Eleagnus, Euonymus, Fuchsia "Riccartonii", Garrya, Hippophae (Sea Buckthorn), Blackthorn, Griselinia and Tamarix may all thrive. They will need to be well staked and protected in the windiest areas.
This has been an introduction to hedging and is given in good faith but cannot be expected to cover all situation. For more complete details at a very reasonable price we recommend the Royal Horticultural Society's excellent concise guide. This costs just £4.99 from RHS at www.rhs.org.uk or 01483 211320.

CHOOSING A TREE FOR A SMALL GARDEN

2008-10-22T02:37:00.000-07:00

Many of us have small gardens and naturally we want to make the most of them. A tree can set the atmosphere of a garden faster than almost anything else and so choosing the right one can be important. If you choose the wrong one you can spend several years being disappointed and more years waiting for a replacement tree to establish itself.

The trees you like best will be entirely a matter of taste and personal association but there are other questions which determine whether they will thrive and look right in the situation which you provide. These are questions of soil conditions, exposure, hardiness, shade, closeness to buildings and boundaries, site lines and final height. With all these factors to consider a good starting point is to see what thrives locally in other gardens and parks. If they do well in your neighbourhood they are more likely to thrive in your garden. You may find it difficult to put a name to a tree which you like. Some public parks and arboretums have labelled their trees making the task much easier for you. It is also my experience that people who enjoy their own gardens will happily share advice, so don't be afraid to ask what the tree in their garden is called and how happy they are with it. In addition there are some excellent books and below I list three which have been useful to me over many years.

The conditions in your garden.

Firstly the soil. Some trees will not thrive in acid soil, some not in thin chalky soils, some will hate wet soils and some soils which are very dry. There are many however which are tolerant of a wide range of conditions and I list a few below. You can test your soil using a test kit from a garden centre or send off a sample to an expert organisaion such as the Royal Horticultural Society. I have never bothered because I can see what does well in my neighbourhood and I know that the soil in my small garden has been cultivated for a hundred years and is a couple of feet of topsoil over clay and limestone. Digging a test hole however will give you an idea of the depth of topsoil (topsoil is the darker soil full of decayed vegetable matter which is at the surface of all natural soils), the amount of clay or rock and the dampness. You shouldn't despair if you only have a couple of feet of soil before you get down to clay or rock. Many trees thrive in this amount and the majority of roots of even large trees tend to be in this top layer.

Hardiness. Within the United Kingdom there is only a limited range of weather conditions but exposure to winds or salt from the sea can greatly effect a tree's chances of survival. Across a continent the size of North America or Europe there is a much greater range of conditions and you may need trees to thrive in the extremes. The books below would give you a good idea of trees for difficult conditions.The Hilliers Manual in particular gives excellent lists of trees and shrubs for many situations and to provide many different effects. Trees for a Small Garden (see below) gives maps of hardiness zones so that you can judge whether a tree is likely to survive.

There are several groups of trees which contain species and varieties suitable for a wide range of conditions and which are unlikely to finish more than 15-30ft high. The most useful are probably Malus (apples including crabs), Prunus (cherries and a large number of related trees), Sorbus (rowans, whitebeams etc), Crataegus (thorns) and Betula (birches). I would add Acers (maples) and Salix (willows) for more particular situations. There are few evergreens amongst these groups and so Ilex (hollies) and smaller conifers may also need consideration.Within these groups is a large selection of many of the most valuable small trees. However, since the selection is so big, you will need to be pointed in the right direction to make your choice. If you don't have the name of a particular tree you will need to either visit an arboretum or other public garden, where trees are labelled for you to judge them, or you will need to look the trees up in books or on the web. There are two outstanding books useful for judging trees (and indeed other plants as well). These are -
The Encyclopedia of Plants and Flowers published by the Royal Horticultural Society. This contains brief details of most of the most useful trees and garden plants and photos of a huge number of them. It costs around £30 but could save you from making all sorts of mistakes in choosing the wrong plants. It makes a wonderful present.

The Hillier Manual of Trees and Shrubs which covers most of the plants in these categories commonly grown in gardens. The pocket edition costs around £15.

In addition I use Trees for The Small Garden by Simon Toomer, published by Timber Press. It is around £20 or $30

PLANTING A WINDBREAK

2008-10-22T02:17:00.000-07:00

There are many situations where creating a garden is made very difficult by strong winds. These in themselves can make it hard to establish more sensitive plants but if the winds carry salt from sea water or are particularly cold the challenge is even greater. Planting a windbreak can dramatically reduce the winds suffered by both our plants and ourselves.

The first thing to remember in establishing a windbreak is that it is better to filter the wind rather than create a solid barrier. A wall or a building might at first seem like the best way to protect an area, but solid barriers create eddies and turbulence around them which may be worse for plants and for you. We are all familiar with the strength of winds between city buildings. In a similar way walls which create immediate barriers to wind also produce strong eddies and swirls of wind around them. Plants tend to filter the wind rather than deflect them so that the strength of the wind is reduced rather than simply moved to another place. They are also less expensive and generally more attractive than walls, generally improve with time and may need less maintenance.

In planting a windbreak you will need to start with a good idea of the predominant wind in your neighborhood. For most places there is a direction from which the majority of winds arrive. For instance most of the UK is subject to predominant winds from the south west although damaging cold winds can also come from other directions. For a garden located on a cliff or headland there may be frequent strong winds from more than one direction. Whichever you suffer from you will need to know about them in advance so that the trees you plant will be in the right place. It may take years to establish the windbreak so it is definitely worth getting this right the first time.

The general principle when planting a windbreak is to establish a row of large trees with dense smaller trees and shrubs either side of it on the windward and leeward sides. These smaller trees and shrubs greatly add to the overall filtering effect. As a general rule the effectiveness of an established windbreak usually stretches on the leeward side of the break for a distance which is around 5-10 times the height of the trees, but there may be some effect up to around 25 times the height. So if your trees are 30ft high the windbreak may be effective for more than 2-300 ft.

To choose plants which will do the job in your difficult situation the first thing to do is to look at the trees and shrubs which are already thriving in your neighbourhood. You may find that there is Sycamore and this is one of the few situations in which the planting of these tough trees can be easily justified in the UK. Generally they are considered a "weed tree" as they are very invasive and support little wildlife compared with native species.They are however a traditional windbreak for hill farms and exposed settlements and can provide the same function for a garden. They will of course lose their leaves in the winter and so a large evergreen tree species should be added to the windbreak. Austrian Pines, Pinus nigra, are excellent in this situation as they are resistant to strong winds and salt and do not need good soils. For an understorey of smaller trees and shrubs you would again be well advised to find out what thrives already in your neighbourhood. Near to the sea likely evergreen candidates will be Griselinia, Arbutus, Holly, Hebes, Eucalyptus gunnii, Olearia, Berberis darwinii, Phormium and Cordyline. Many of these will not thrive in cold and exposed sites. Evergreen shrubs for colder areas might be Eleagnus, Euonymus,Mahonia, Myrica, Rhododendron, and Viburnum. Deciduous trees for both situations may include Rowans and Whitebeams, Birches , Ashes , Beeches, Alders, and Willows. Shrubs could include Fuchsia riccartonii, Rosa rugosa and Gorse.

Of course planting and establishing trees in exposed conditions is also a problem. Our natural instinct is to stake them high and tie them three or four feet above ground level. However there is a problem with this. We should think of the trunks of trees in some respects as being like the muscles of an animal's body. The more they flex and are challenged the stronger they become. Therefore if we stake a tree high and then, after several years, untie it from the stake we will often find that it has not built up sufficient strength to stand alone. Our aim should be to stake it low so that it can still flex but the rootball can't move and loosen the roots. It is sufficient here to say that the tree should either have a low stake at an angle to the tree trunk, have two low stakes joined by a crossbar or should be secured by ground anchoring. Whichever system is used the stake should not go through the rootball, the above ground ties should be loosened a little each year and the tree roots should not be allowed to dry out for a year or two at least. Ground anchoring is a specialized way of securing a tree by tieing its rootball in a non-damaging way below ground. If done correctly the rootball won't move and nothing except the tree is visible above ground. It is an ideal way of planting a tree but requires rather more skill and expense than the conventional ways using stakes.

A good windbreak will take some years to establish but within it a surprising range of delicate and sensitive plants can often survive and, in addition, we humans usually feel a good deal more comfortable as well.

LARGE TREE, SMALL GARDEN. CAN THIS EVER BE SAFE?

2008-10-22T02:12:00.000-07:00

The question of how close to your house to plant a tree is a complicated one. After a dry summer there is usually a rush of claims to insurance companies after subsidence occurs. The problems generally happen in areas where there is clay soil as tree roots can remove the water from the clay producing shrinkage. This shrinkage may result in movement of foundations and the walls which they support. Exact information is hard to give but it is possible to give a few generalisations.

I take my information from a textbook on the subject - "Tree Roots and Buildings" by Cutler and Richardson published by Longman Scientific and Technical. They work from reported problems and give the distance from buildings within which 50% of the incidents occur. If the incidents occur close to a building for a particular species this is considered to be a less dangerous tree to plant than one which gives problems at a greater distance from the house. So Willows, Poplars, Oaks and Elms can give problems at far greater distances than birches, hollies, apples and rowans.

It may be wise to consult your insurance company before you plant a large tree. Be aware however that they are likely to give a very conservative response and that our cities would be far poorer places with many less fine trees if insurance companies were the arbiters of all tree planting.

There is another way to look at this problem. In many countries street trees are planted into prepared planting pits along the sides of roads. These are effectively large sunken plantpots which allow space for tree roots to develop without interfering with buildings, drains or other services. If you are keen to plant a large tree into a space near to walls, buildings, or services it may be possible to create a pit. For large trees you would need a pit around 6ft x 6ft and 3ft deep. This would have thick walls of blockwork or, alternatively, welded steel. You would be making an enormous container with drainage holes to prevent it turning into a sump or underground pool. Drainage holes should be protected by mesh to prevent tree roots from escaping through them and defeating the purpose of the pit. It would be essential to ensure that the container can drain properly and so it is unlikely to work if the pit is dug into clay unless you provide an efficient drainage system from the pit through the clay and away.

In order to water the tree effectively and, almost as importantly, to allow air to the roots a perforated plastic tube around 50mm in diameter should be buried within the pit and to the depth of the pit but with its inlet just above soil level. These tubes are available from tree and landscaping suppliers but can be improvised from drainage pipe if necessary.

If made well this pit should allow a tree to thrive in a limited space without danger to its surroundings.

PLANTING A TREE

2008-10-22T02:03:00.000-07:00

The principles of tree planting are similar whatever the size of tree. The idea is to try to disturb the tree as little as possible, place it in an appropriate hole and in a situation to which it is suited. An acid loving tree should not be planted in chalky soil, nor a sensitive tree in an exposed location. Some trees need good drainage or are less tolerant of frost or sea spray. Aftercare and staking are then designed to help it settle in. Larger trees of course will need more expert handling and those in pots over about 70litres in size may need moving and planting using machinery.
To prepare for planting, a hole a little larger than the pot needs to be prepared. In heavy clay this would need to be broken up around the edges and bottom to prevent it from turning into a sump filled with water which would suffocate the tree roots. In other soils this is not necessary. Neither is it necessary to feed the tree at planting or provide rich compost as it is useful to encourage the tree's roots to search for nutrients by growing into the surrounding soil. The tree should be planted so that the ground level is close to the level of the surface of the compost in the pot.
STAKING. Most trees will need some staking to prevent the wind from rocking the tree loose. It's necessary to take into account both the size of the tree and how exposed it will be to strong winds. Tree sizes are usually measured by their girth (which is their circumference in cms at 1m above the ground) if they have a single stem or by their height and pot size. For most trees up to around 16cm girth in a normal garden situation staking is by using a single stake driven in at around 45degrees and facing into the predominant wind which is often from the south west in the United Kingdom. The stake must be driven firmly into the ground avoiding the rootball as far as possible. It will usually cross the stem of the tree about 60cm above the ground. A well cushioned adjustable tree tie is attached and it should be loosened as the tree grows. Generally it can be removed after 2 or 3 years. For larger trees double staking is used (and occasionally guying and ground anchoring for larger trees or difficult situations) which consists of using two tall vertical stakes.These would be either side of the stem and outside the tree's rootball. The stakes are joined by a cross-piece which is attached to the tree by a cushion and tree tie. For very flexible young trees it may be necessary to use a taller single stake which can be reduced in height as the tree establishes. The general principle is that trees get stronger by flexing and adapting to adverse circumstances just as the muscles of an animal do. Over-staking therefore tends to produce weaker trees in the long run.
AFTERCARE It is surprising the extent to which weeds and grasses can compete with tree roots for nutrients and water. For trees planted into lawns or meadows therefore it is important to leave a clear circle about 1m in diameter until the tree is well established.. Mulching with a mulch mat or with about 50mm of bark can help both to keep weeds down and to maintain moisture levels in the soil. It is of course essential not to let the rootball dry out for at least the first year (see below). Pruning of laterals (small side branches coming from the main stems) and of dead or diseased branches can be carried out at planting.
WATERING. It is always important to remember that a large percentage of the losses in the first year or two are caused by allowing the roots of the tree to dry out. Periods of drought are especially dangerous. However watering little and often can encourage the roots of the tree to stay near the surface instead of spreading to seek new sources of water. The spreading of the roots will also, of course, stabilize the tree long after the stakes have been removed. For these reasons it is sometimes better to water trees through tubes sunk at the time of planting which provide water to the roots a foot or two below the surface. Failing this, surface watering systems such as leaky hoses can be useful especially when combined with mulches (although there are also trees, even species such as yew native to our better drained soils, which do not thrive if the soil is damp and mulched around their roots).