Country & Garden: Pruning time is here again

IT IS an irony of gardening life that we have most time to spend in the garden when there are the smallest number of tasks to be done.

February is the month when there is least else to distract me, yet when I prowl around the garden looking for things to do I am forced to discount most of them as unsuitable. It is too early to sow seeds in sodden ground, stake perennials or mow. A mild, damp winter, such as we have just experienced, is the very devil, for it encourages precocious weed growth, yet the soil is too wet for congenial and easy weeding. Thank goodness, then, for summer-flowering deciduous shrubs which need to be pruned and so give me something to do.

Pruning late-summer-flowering shrubs, in fact, makes falling off a log look a dangerously complicated procedure. Those plants that flower after midsummer almost all do so on "wood" (ie shoots) that are "made" (ie grow) this season rather than last. Pruning these therefore consists of cutting back all the old shoots, which flowered last year, in order both to make room for new shoots and also to give the plant an enormous stimulus. Most plants which require this treatment have already begun to show "breaking" buds, so the pruner has a guide; he or she need only cut just above these incipient leaves, to stimulate them into growth and, ultimately, flower.

The best-known example of a suitable case for this treatment is Buddleia davidii, which flowers in July and August. Of course, it will flower even if left unpruned but, in the context of the garden, the old injunction "keep your shrubs young" is a valid one. The way to prune buddleia is to cut back the long, flowered stems to the permanent framework close to the ground, and cut to ground-level one or two of the oldest branches, if they have become woody, hollow and congested. Buddleias are a good shrub to practise on if you've never done this sort of thing before, because their vigour means that you can be pretty drastic.

Once you see how easy it is, have a go at Caryopteris x clandonensis, Ceratostigma willmottianum, lavatera, Perovskia atriplicifolia, and the summer-flowering spiraeas such as S japonica as well.

This principle of pruning applies also to autumn-fruiting raspberries, such as `Autumn Bliss' and `September'. These are specially quick-growing varieties, capable of doing the whole business between February and September. If you cut back the existing shoots almost to ground level, new ones will grow up rapidly and strongly to replace them.

All I have said applies to clematis that flower after midsummer. Clematis, like roses, seem to promise endless difficulties and complications in their pruning but, in fact, the basic rules of pruning should not be abandoned but, on the contrary, rigorously obeyed. Late-summer flowers (what are known as Group 3 clematis), are pruned hard to encourage this season's growth. Cut the stems back to a pair of good buds less than 1ft (30cm) from the ground.

You don't have to be too pernickety about it; if your clematis is in a real tangle, you can grab a bunch of stems and clip straight with the secateurs, as if you were an old-fashioned Army barber. It seems callous to cut away "breaking" buds, I know, but there is no helping it with a climber that comes to life so early in the year.

After an agreeable afternoon spent pruning clematis and other shrubs, you will have a good deal of (mercifully light) rubbish to get rid of. If you are in the habit of shredding your clippings, or you live in a district where you are allowed to put them on a bonfire, leave them in a heap for a while first, to give the small birds in your garden the chance to find suitable material for their nests.

That way everybody in the garden is happy.