Gardening: Trim down in wintertime

Pruning will shape up your trees and give the garden more of that much-needed light.
A recent visit to the hairdresser has reminded me of the Benjamin Franklin quote: "Beware of the young doctor and the old barber."
The hairdresser wasn't old but she certainly had things on her mind other than satisfying my regular, if somewhat contradictory, request to cut it without taking any off the length.
I emerged looking considerably worse than our Magnolia Grandiflora, which we mercilessly hacked back a few months ago and which is now about a foot taller and considerably bushier than it was before the surgery.
I fear it will take my hair rather longer to recover, although if it grew back as thick as the magnolia I couldn't be anything but pleased. Not likely, though.
It does beg the question, however, of when, how, why and how much to prune and, irrelevantly, what it is about the onset of winter that makes us want to slash and hack?
In my case it's probably boredom. There's not much else going on in the garden and I want to see something looking different. Decimating a few innocent trees changes the landscape by letting in more light and opening up new views. But there are probably better reasons.
Most people prune because trees and shrubs have become overgrown and untidy, or are in poor health. And although pruning may solve the problem, it's better to have a regular pruning schedule so such problems don't occur at all.
You can prune to maintain shape, reduce size, increase fruit, foliage or flowers, direct and manage growth, and to enhance health.
Late autumn's a good time to do the business because it gives plants time to harden when there's no new growth. Pruning when the tree is dormant reduces sap loss and minimises the risk of insect or fungus attacks. If you can, check out the long range forecast and try to do it when there's a fine spell under way, since cutting trees in damp weather increases the risk of disease.
Before you embark on the task, assemble the tools you'll need. There's nothing more frustrating than finding yourself at the top of the ladder without your secateurs. For serious pruning, you'll need secateurs, long handled loppers, shears and a saw. And last season we bought a rather complicated tool, with a very long handle and a cord to close the blades, designed for dealing with high branches. It was inexpensive and it works a treat.
If you just want to shape a camellia or tidy up the top of your hedge, common sense and a good eye are about all your need. But serious pruning, ie sawing off big branches, requires a bit of knowledge.
Look closely at the branch you want to remove. There'll be a bit of a bulge in the bark - the collar - where it joins the trunk, and your cuts should be made on the branch side of this collar. Don't cut into the collar or directly flush with the trunk or you may cause damage.
Using a pruning saw, make your first cut about 12cm out from the trunk on the underside of the branch. Initially, cut only one-third of the way through the branch to prevent a tear in the bark running back to the tree and damaging the branch collar. About 5cm further out from your first cut, saw right through the branch, starting on its upper side. Then trim the remaining branch stub by making a third cut parallel to the trunk and just outside the branch collar.
After pruning any tree, disinfect your pruning tools with a weak solution of bleach and water, then rinse and dry before moving on to another tree.
More specific information on how best to prune different kinds of trees is available in books, garden magazines and on the internet.
Tips:
Consider every cut before you make it, from every angle around your tree, and repeat the process after each cut. Remember, less is more when you're wielding the loppers.
If your camellia is looking untidy, prune immediately after flowering. Prune the lower branches to lift the shrub off the ground and open it up to the light by aiming for 10cm gaps between the layers of branches at the tips.
Don't prune deciduous shrubs and trees before flowering or fruiting or you'll compromise both.
Trim the sides of a hedge to encourage dense, even growth from the top to bottom.
Trimmed hedges should be slightly wider at the base and slope in at the top. This allows light into the base of the plant.
Keep your groundcovers dense and lush with an occasional shearing. Trim to keep them from encroaching on paths and edges.