The garden of our new home has a beautifully cared-for formal hedge of purple-leaved plum alternating with green-leaved plum and beech. What other care will the hedge need besides the annual cutting?
Once a hedge is established and has grown to the height required, little routine care is needed apart from clipping. However, it is important to keep weeds from infesting the roots, particularly perennials such as ground elder and bindweed, so regular weeding should be carried out.
Other common weeds of hedges are nettles, couch-grass, dock, and dandelion, which are all difficult to eradicate once they become established. Watch out also for tree seedlings such as sycamore, hawthorn, and elderberry, which can rapidly grow unnoticed amongst the hedge plants.
You should give the hedge a dressing of well-rotted organic matter (manure or compost) in spring or autumn; and, each spring, clear the hedge bottom of rubbish accumulated during the winter, taking the opportunity also to remove all dead growth.
Colt’s-foot has encroached around the base of my privet hedge. How can I destroy it without also harming the hedge? Digging it out seems to be impossible, as its roots are inextricably entangled with those of the privet.
When weeds with extensive roots or creeping underground stems invade a hedge, weedkillers are the only remedy, short of digging up the hedge. Even repeated hand-weeding every year is not completely successful, as some of the root always survives to fight another day. Use one of the weedkillers based on glyphosate, painting it on to the leaves of the colt’s-foot.
Colt’s-foot is one of the most difficult of hedge weeds. Others, which should be dealt with in the same way, are ground-elder, bindweed, couch-grass, horsetail, and creeping thistle.
I have noticed locally that hedges which are kept clipped close vary considerably in shape; some of them have a rectangular outline, some a curved top, and so on. Is there an optimum shape, and if so, can you please explain why?
Yes, there are in fact two preferred shapes: the rectangular one with completely vertical sides from base to top; and the other with tapered sides, the base being broader than the top. If the base is narrower than the top it will become bare and badly clothed with growth, and the top-heavy upper part will get damaged by wind and snow.
Is there any reason why the top of a hedge should not be curved, or cut in some other way than horizontally? Is it detrimental to the hedge?
No, curved and shaped hedgetops are not damaging to the hedge’s growth, but they do need more skill in clipping. It is sensible to decide on the shape early in the hedge’s life, so that it can be trained accordingly. To alter it when it is mature could produce variations in the hedge’s density, and even result in ill-health. Undulating, castellated, curved, pointed, or rounded are all possible shapes, provided the hedge base is not narrower than the top.
So many hedges, whatever they are made of, seem to be thin and bare of leaves at the base. Can this be prevented?
Yes. Some of the trouble is due to poor nutrition, but mostly it is due to incorrect clipping from the time of planting. In order to induce good thick basal growth, the height of most hedging plants has to be considerably reduced in the first two or three years. This encourages it to send out side growth low down. If the side growth is trimmed back to tidy it up, the clipped sideshoots will sprout further sideshoots, giving an even denser cover.
When is the best time of year to cut a hedge whose leaves fall in the autumn?
There are two kinds of deciduous hedge: those which grow at a moderate rate, and those which grow fast. Those which grow moderately, producing new growth about 300-450 mm (12-18 in) long during the season, should be cut in August. This applies to beech, hornbeam, hazel, and tamarisk. If they are growing particularly well, however, they may benefit from two trimmings—one in late July and another, light one early in October.
Fast-growing hedges, such as blackthorn, myrobalan plum, and hawthorn, will need about three clippings at six-weekly intervals (so too, incidentally, will the evergreens gorse and honeysuckle Lonicera nitida).
I have been told by a local gardener that the right time to cut my Leyland cypress hedge is in the autumn—but it grows so fast that, if I leave it until then, I find I have to take secateurs to it, and it is now getting rather thin in places. Can you advise me please?
Early autumn is certainly the right time to cut some evergreen hedges, such as spotted laurel (Aucuba japonica ‘Variegata’) and all the other laurels, Elaeagnus pungens, sweet bay (Laurus nobilis), and x Osmarea burkwoodii. But the fast-growing evergreens, including conifers, are better trimmed either once (in August) or twice (in late July and in early October). This will keep them under control and ensure that they have thick, close growth. Hence your Leyland cypress needs to be cut earlier than you have been advised.
There are one or two evergreens which need even more cutting, notably gorse and Lonicera nitida .
I want the hedges in our smallish garden to be a definite feature rather than just an enclosing background. I intend to use flowering species of hedging plants, and we will be making our choice from Camellia japonica, Mexican orange-blossom (Choisya ternata), Hebe speciosa hybrids, and Pittosporum tenuifolium (the last for its evergreen leaves). What is the correct method of trimming these plants when they are grown as informal hedges?
Plants such as these, which grow slowly or flower from side growths, are very easy to maintain. They simply need any long straggly shoots cut back in autumn or spring to make them tidy, and their dead flowerheads removed.
The tiny low-growing hedges that form edgings to beds of summer annuals always look so neat and exact. Is there any special method of clipping them?
The formal edgings you mention need close cutting about once a month from the end of May, until late in August or early September. Use razor-sharp shears, and cut exactly to your guiding line, which should be tightly stretched between supports .
I recently passed a beautiful flowering hedge formed of roses, but I have been unable to discover the name of the variety. Its flowers were salmon-pink, with a strong perfume. Can you identify it, as I would like to grow it?
The hedge you describe seems likely to be one of the hybrid musk roses, called ‘Penelope’. It flowers from June to September and has good scarlet hips in winter. There are several other hybrid musks with flowers of different colours, but equally decorative. To be seen at their best, such hedges must be at least 1.5 m (5 ft) wide; if less, they will be rather disappointing. To get this effect, they are pruned late in February by cutting short side shoots back so as to leave three buds, cutting long new shoots from ground level by a third of their length, and removing entirely some of the oldest growth. In summer, the faded flowers are removed at once to encourage further flowering.
I am told that a laurel hedge should not be cut with shears or a mechanical hedge trimmer. Is this true?
Yes, because the leaves will unavoidably be cut in half by these methods, and will turn brown. Eventually this damage may weaken the hedge, as such leaves will fall. Although rather laborious, it is better to use secateurs and cut stems individually.
I never seem able to get an even, level cut on my hedge when I give it its annual trim. How can I obtain a really neat appearance?
First, check whether your hedge is one which does indeed need only one clip, or whether it should have several. If the latter, it will be difficult with only one cut to keep it smooth, as so much material will have to be removed. Second, when cutting, stretch a line tightly between two posts along the top, at the height you want the hedge to be, and clip exactly to this level. For the sides, put in canes vertically at intervals along the hedge, and sight along these as you cut. 442
How and when should I trim my informal flowering hedge?
In general this type of hedge needs only to be pruned, rather than cut all over; do this once a year, in spring if it flowers between mid-summer and autumn, and in mid-summer if it flowers in spring or early summer. In either case, take off the shoots which have flowered, thin out the growth if it is crowded, and remove completely any old growth which is straggly and flowering badly.
What is the quickest and most comfortable method of hedge-trimming using shears? I find such work very tiring.
Keep the shear blades really sharp, and use shears which are well-balanced, comfortable to hold and of a weight suitable to your strength. Indeed, before you buy shears, check that they have a cutting action which does not jar your wrists. Do not try to reach up or stretch—this is tiring and is one of the causes of unintentionally wavy hedges. Use step-ladders if need be, and keep the hedge of such a width that the middle of the top surface is easy to reach from either side. Cut the sides from the base upwards, otherwise the trimmings will get caught in the uncut hedge below. Put sacking on the ground beside the hedge to catch the trimmings.
Can you tell me how to train a hedge by the method known as laying?
Basically the method consists of making a long slanting cut partly through a stem about 300 mm (12 in) above ground-level, then bending the stem sideways and weaving it around stakes already put in position. It is used on old hedges which are overgrown and thin in patches in order to renovate them and encourage new growth from the base of the plants. The stakes are put in behind the hedge at an angle of 45 degrees and the layers (stems) are bent the opposite way across them and at right angles to them. Weak, damaged, and straggling shoots are removed at ground level, and four or five of the straightest shoots remaining on each plant are used for laying. The stakes are bound together along the top for neatness and security while the hedge thickens up.
I have a row of overgrown lime trees which originally formed a screen and which I want to cut back and pleach. Are limes suitable for this kind of training and what are the details of the method?
Limes can certainly be pleached: they have pliable growth, and the shoots rapidly grow long enough to be woven in and out. Once the trees have been cut back to the height you require, the lower part of the trunks should be cleared of side-growths; horizontal bamboo canes or wires are now attached to the trunks and placed between the trees. Then shoots are allowed to grow out sideways; any which are produced fore and aft are removed completely. The sideshoots are tied to the canes and, when plentiful enough, are interwoven with one another. As the shoots mature into branches, the canes or wires can be dispensed with and new growth trained amongst the old.
What is a ‘fedge’?
A fedge is a combination of a fence and a hedge, and usually consists of a wooden fence over which a climbing plant is grown. For instance, the variegated ivy Hedera canariensis ‘Variegata’ (white-variegated) or H. dentata ‘Variegata’ (yellow-variegated) can be trained to cover a fence completely and will need hardly any care. Similarly, the trailing winter jasmine (Jasminum humile) and Forsythia suspensa sieboldii, with its long pendulous shoots, can be trained in and out of the stakes of a rustic or palisade fence. You can also make a frame to replace the fence component out of thick wire bent to the shape you want.