Power to your pruning

By Meg Liptrot

Get your pruning right and your trees will be happier than ever.
Photo / Meg Liptrott
Photo / Meg Liptrott

It is safe to say that good pruning provides the foundation to a healthy and shapely
garden, and is an essential winter activity.

It also helps get your blood pumping on a cold day.

When to prune

Pruning deciduous trees and shrubs in winter allows you to easily see the structure of your tree and spot dead or diseased branches. Pruning allows more airflow and light into your plant, and helps reduce fungal problems and pests. It also encourages fruit to form.
Remember to prune on a dry day as there are fewer fungal spores in the air to infect the pruning cuts. Sharp secateurs, loppers and a pruning saw are your essential tools. Keep your tools sterile by wiping with meths between cuts.

Where to make the cut

Avoid pruning too close to the trunk or supporting branch. There is a slight swelling at the base of your branch called the "collar" which should not be cut off.

Cells inside the collar heal the wound and form the ideal donut-shaped "callus". Leaving a branch stub too long can cause die-back.

When shortening lateral branches and shoots, prune just above an outward-facing bud, cutting on a 45-degree angle. Lateral branches are generally cut back by a third.

Fruit tree pruning tips

Fruit trees have particular pruning requirements depending on the fruit type. Some fruit are tip-bearing, others such as apples grow on clusters of spurs. Peaches and nectarines fruit on shoots grown the previous summer. Plums and apricots fruit on two-year or older wood, apples and pears also fruit on two-year or older shoots and spurs.

The key is to learn to recognise fruiting spurs or blossom buds and leave those on, and prune the old, less-productive branches and spurs off to stimulate new growth. Hard pruning stimulates strong growth of leafy shoots at the expense of fruiting. Moderate pruning encourages fruiting and shoots, light pruning encourages fruit, but little new growth. The aim is to achieve a balance. Fruit trees are generally grown as a central leader or pyramid, or more commonly a "vase" shape for the home garden. For both styles, remove branches that are too close, damaged or rubbing together. A basic rule of thumb for the "vase" is to remove branches that are growing inwards, and prune lateral branches to outward facing buds. Aim for an open shape with branches at around a 60-degree angle to the trunk.

When pruning young trees, you are shaping the main "scaffold". Visualise where the branch from that bud will grow. Imagine you're looking into the future when you prune and create a strong, simple structure for your tree.

Sometimes grafted trees send vigorous shoots out from the root stock at the base of the tree. These shoots should be pulled out or cut as close as possible to the trunk to prevent regrowth.

Training

When new branches are pliable, training techniques such as hanging weights or using stakes or guy ropes with padded ties to hold branches in place until they harden can help to shape the tree. Espaliered fruit trees can be incrementally trained to the correct horizontal angle - don't force it.

Pears require the least pruning, but are very upright in their form. Short lengths of wood can be used as spreader sticks to hold branches at a correct angle. Training devices should be removed when the branch no longer springs back - usually within a couple of seasons. A branch growing at an open angle encourages better fruiting and reduces the likelihood of a branch to split when carrying a load of fruit. Keep standing back to admire your artwork, as pruning and training is certainly an art form. Achieving balance and harmony in your tree takes time. Breathe, have a cup of tea when you're tired, pull up a seat and contemplate.

Garden Escapism

Take the edge off the winter chill and visit the hot house at the Wintergardens. You'll be transported to far off tropical climes. Remember the Corpse Flower (Amorphophallus Titanum) excitement last November? These fascinating plants are worth visiting again.

Two Corpse Flower corms have produced a leaf, each the size and height of a small tree. You could be forgiven for walking past thinking they are palms with curious spotted trunks. In the cooler glasshouse orchids are on show, alongside a cacti display.

Rose pruning

If you've not yet pruned your roses, there's still time. Roses which flower en masse in spring, such as Banksia, old climbers and heritage roses, are better pruned after flowering. Visit the rose beds at your local council gardens or botanic gardens for reference if you're challenged with rose pruning at home. Find the same rose type as yours for appropriate pruning style.

• I'm off to the snow for my honeymoon, so we have a guest landscape writer filling in for a couple of weeks. See you in spring!

Fruit tree pruning workshop: Sustainable Living Centre, Saturday, August 30, phone (09) 826 0555 for more info.

- Herald on Sunday

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