Gardening: Now, the sculptor's tale

Good pruning is not the same as cutting back. It's an art practised in three dimensions.

A reader from Canterbury advised: "Think of yourself as a ground elder plant", when I signed off this column three months ago to do battle with cancer. "Dug up, poisoned, attacked from all sides, but still flourishing". Such sensible advice. To all those who wrote - thank you. It mattered and it helped.

It was fortunate that the hiatus in our garden happened towards the end of the growing season, rather than at the beginning. There is plenty of time between now and March to catch up on routine jobs: weeding, tying in, cutting down, pruning. At the moment, pruning is most on my mind.

Good pruning is not the same as cutting back. When a shrub is overhanging a path, you can simply shear off the offending growth and think you've solved the problem. But the shrub will look awkward and butchered. If you take each growth in turn and make the cut where that branch joins another branch, your intervention will be less obvious and the natural habit of the shrub will be maintained.

Think of your work as sculpting. Look at the shrub from all angles as you are working on it. If you nibble too much on one side, you may unbalance the whole. When I first started to garden I was very much against this kind of intervention. In a fuzzy kind of way, I supposed that everything could be left to its own devices, and that the result would be charmingly romantic. It wasn't. All I learnt was that bullies quickly dominate. The gardener's role is really to make sure that underdogs have a head start.

So I've been snipping away at a smoke bush (Cotinus coggygria), both to clear a way up the bank and to lift some of the shrub's lowest branches from the heads of the little cyclamen below. They are not exactly underdogs, as they hang on with grim determination in the most unpromising situations, but with the leaves of the smoke bush out of the way, it's much easier to see and admire the cyclamen with their amazing mottled leaves. There are not many hard-and-fast rules in gardening but one of them is that you can never have too many cyclamen.

Lifting the canopy of a shrub or tree allows more light to percolate through to the ground below. Cyclamen, being stout troopers, will put up with quite dense shade, but autumn crocus and colchicums do better with some sun on their faces. So this was why I also took the secateurs to a biggish osmanthus. Because it's evergreen, there's no season when the plants round its feet get a glimpse of the sky above. Working gradually round the bush, I took off the lowest branches altogether, making the cuts close to the main trunk.

Then it gradually seemed as though the bush itself would be better shaped into a gentle sphere, not clipped tight, as a globe of box or yew might be, but just coaxed into a form that would keep it separate from its near neighbour, the grey-leaved rose, R glauca. That was a typical case of a romantic vision turning into a mess, with the rose tangling with osmanthus on one side and a Judas tree on the other.

But what about the osmanthus's soul? What about that "natural habit" that seemed to be the point of pruning only a few paragraphs ago? Well, the fact that osmanthus has got small, dark evergreen leaves, makes it a suitable candidate for topiary-like treatment, unlike, say, deciduous forsythia, or large-leaved mahonia. But if you clipped it as hard as you might a box ball, you would lose too much of its sweet-smelling blossom. So you settle, if you want, for something in between.

The absence of hard-and-fast rules seems a nightmare when you first start to garden. You need at that stage to feel that if you do A and B then C will gloriously happen. Sometimes it does. But as you go on gardening, its freedom from rules, its endless possibilities, constitute one of its chief delights.

If there were rules that we all followed, then gardens in comparable areas would look too much the same. But because we have so many choices, whether to cut back or not, whether to train or not, whether to pluck out self-set seedlings or not, each garden acquires an entirely individual imprint. In the end, the small choices are the ones that matter, because they accumulate to give a particular look or atmosphere to a place.

Nibbling at the smoke bush, fiddling with the osmanthus, were no more than what you might call cosmetic pruning. The kind of pruning you do to enhance flower, foliage or fruit is more critical. You are manipulating growth patterns to get a particular effect, and you can't do that effectively without understanding a little about the way the plant works.

Morello cherries, peaches and nectarines, for instance, will all fruit next year on shoots that were made this year. That is to say, they fruit on new wood rather than old. So to get the best crops, you have to encourage the tree to make as much new growth as possible. In this country, these three trees are best trained flat against a wall, which protects the early blossom and provides extra warmth to ripen the fruit. Nectarines are the trickiest to grow outside.

Left to itself, each tree will grow vigorously, but the new growth will just be at the end of existing shoots. Gradually the whole centre of the tree will be made up of old, unproductive wood, and your only chance of crops will be on the fringe of fresh growth around the outside edge of the fan.

With fan-trained trees, of course, pruning has to go hand in hand with tying in. The tree doesn't grow flat by nature. You have to coax it into doing what you want it to do, by choosing and encouraging the shoots that grow in the right direction for your purposes, and rubbing out those that don't. That usually means getting rid of the stuff that old gardeners call "breastwood" - shoots that stick out from the front of the tree, directly at right angles to the wall.

But what you can do now is to cut back some of the long, straggly growths on the outside of the fan, to force the tree to leap into the growth elsewhere (you hope in the middle). I fiddled around for years with a pruning manual in one hand and my secateurs in the other, wild with frustration because the picture in the book never looked like what I'd got in front of me. If you understand why you're doing the job, it's easier to get to grips with the how.

A Quick Snip: Pruning Tools

I'M WEDDED to my Felco secateurs, partly because, with their bright red handles, I can see where I've left them in the undergrowth, but mostly because they are so beautifully designed and easy to use.

You can also send them to be serviced and resharpened, which is not a benefit that many manufacturers offer. They are expensive. Expect to pay about pounds 22 for Felco No 5, or pounds 37 for Felco No 6. Both are guaranteed for life and both did well in a Gardening Which? test, as did the Gardena 190 (pounds 10, guaranteed for one year) and the Wolf Garden RR19 (pounds 18, guaranteed for five years).

For thicker branches, to save your secateurs, you are likely to need a pair of loppers. We use Rolcut 20S loppers, which have been fine, but after lengthy tests Gardening Which? chose the Sandvik Anvil P176 (pounds 45) as their best buy. CK's loppers (pounds 50) are also good, once you get used to the ratchet action. You have to pump them several times before making a cut.