WHICH IS THE BEST WAY AND THE BEST TIME TO CUT MY HEDGE?TO

There are two main reasons to keep a hedge trimmed – to make it look attractive and to make sure it grows dense. If you plant hedging plants and then leave them to grow without regular clipping you are likely to get a very leggy hedge with light between the individual plants. Left long enough, like a farm hedge that has not been cut for years, it will eventually stop being a hedge and become a row of taller trees and smaller shrubs. As such it is not likely to act as an effective physical or visual barrier.

There are several methods of trimming hedges depending on the plant varieties used. For newly planted hedges some species such as blackthorn, hawthorn and privet can be reduced to around 10cm immediately after planting. This helps to ensure that they will branch from low down and make thick hedges. Most other deciduous plants are best reduced by around a third in the autumn after planting. To keep a hedge growing densely the main leaders of deciduous plants can be cut back in the following years and side shoots shortened a little. The principle is to make the shoots on the plants divide frequently to give dense growth and this is best done by frequent trimming. In general the more frequent the trimming the denser and more formal the hedge. Once a hedge has reached the size you want the trick is to cut new shoots just outside the basic framework of the hedge allowing a small amount of new growth to be retained.

Conifers are not normally pruned until they have reached the height of the desired hedge. They can then be trimmed several times each growing season if you have the time and patience. Along with privet and lonicera nitida (shrubby honeysuckle) leyland cypress develop their best form if clipped in late spring, midsummer and autumn. Some other evergreeens such as box, lawson cypress, holly and yew do best with a midsummer and autumn cut whereas Cherry Laurel, Oleaster and Lavender should be pruned once in the autumn.

There are other details to keep in mind. If you want the leaves on your beech or hornbeam hedge to stay on though the winter, which many people do to maintain the visual barrier, they should be pruned in late summer. Hedges of laurel, holly or other broad leaved evergreen plants should ideally be cut with secateurs. If they are cut with shears you will produce unattractive brown edges on the cut leaves. Tall formal hedges should also be cut to be a little wider at the bottom than the top. This stops the bottom becoming brown, adds to the stability of the hedge (some tall hedges such as lonicera nitida have a habit of starting to lean when they are more than about 1.5m high) and reduces the likelihood of snow pulling the hedge apart.

There are many other details to maintaining a good hedge. I would recommend the RHS booklet called simply “Hedges” by Michael Pollock ( ISBN 0 7513 47280) as a very good introduction to the subject.