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

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

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.

1. 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.

I

Should I Be Watering My Trees After This Dry Spring

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

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 Rowans, Pines, Yews, Magnolias, Laburnums, and Cherries.

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?

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?

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

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.