When to prune your plants
YOUR GARDEN’S GROWTH WILL SLOW DOWN IN THE COLD WEATHER, AND IT’LL NEED PLENTY OF LOVING CARE TO GET IT THROUGH THE WINTER CHILL. FOLLOW THIS CHECKLIST TO MAKE SURE IT SURVIVES THE SEASON.
Beginners are often intimidated by the task of pruning, but you’ll get over that once you understand why it’s necessary. Pruning allows you to shape and strengthen the plant, so that it becomes more vigorous and produces better flowers and fruit in the growing season.
Winter is a great time to do this, because as the woody plants lose their leaves, you can observe their shape and structure more clearly. July is generally the time to prune woody plants, because they’re at their most dormant in mid-winter. If you’re in a winter rainfall area, you can wait until the first week of August, or mid-August at the latest. Don’t leave it any later, because pruning must be done before the sap starts rising as the spring growing season approaches.
At the beginning of winter, make sure your secateurs, loppers and pruning saws are all sharp. If they’re not, have them sharpened or buy new ones, as this will make pruning a lot easier. Clean cuts enable the plant to heal wounds faster without creating more dead wood. Disinfect instruments regularly with a solution of vinegar or bleach so as not to transfer diseases from one plant to the next.
How to prune:
Start by studying the plant carefully, and envisaging the shape it will be. Take a conservative approach. Remember, it’s like a haircut: you can always cut more later, but once a branch is trimmed, you can’t go back and change your mind!
When cutting branches, follow the stem back to its point of origin and cut it neatly where it emerges from a larger branch or trunk. Don’t leave amputated stumps that will look unsightly and sprout multiple new twigs.
After pruning, seal large cuts with tree sealer and spray with lime sulphur to kill off insects and prevent diseases taking hold. Repeat spraying 10 days later. Feed with slow-release organic fertiliser such as Atlantic Bio Ocean and mulch generously with coarse compost or bark.
First, remove all dead, diseased and damaged branches and thin straggling stems, as well as any side suckers. To check if a branch is dead, scrape away some bark. If there’s green tissue and it’s flexible, it’s still alive.
Cut out branches that cross and rub against each other.
Open up the centre to let light in.
Trim to the desired shape, giving the plant a good, strong structure on which to base future growth.
WHAT TO PRUNE:
Box and foliage hedges should be trimmed regularly throughout the year to keep their shape. Use a sharp pair of hedge trimmers, taking care not to let the hedge get top-heavy. Rather keep the base slightly wider than the top. Flowering hedges, such as plumbago and hibiscus, should be trimmed after flowering.
DECIDUOUS FRUIT AND NUT TREES
Correct pruning can improve the quality of the fruit, so trees should be trained from a young age. The most popular method is to create a vase shape, with a short, strong trunk of about one metre, and then select three or four main limbs which will support a strong framework of secondary branches. Keeping the centre open allows sunlight to reach all parts of the tree, in order to ripen fruit later on.
These need very little pruning. Moderate thinning out and shaping is all that’s necessary.
Herbs like rosemary will need just a little shaping if you pick them regularly throughout the year.
CREEPERS AND CLIMBERS
Shake out dead leaves and twigs, especially those caught on pergolas and trellises, and cut out any dead wood. Port St Johns creepers and granadillas need hard pruning to keep them under control, so cut back the long-hanging lateral shoots to 60 centimetres above ground level. Don’t let ivy get out of hand – cut it back regularly throughout the year.
Prune out old wood and thin stems, then cut the remaining stems back by a third to promote good summer blooms.
WHEN TO PRUNE
While winter in general is the best time to do the pruning, some plants need to be done earlier, and others later in the season.
This table applies to both summer and winter rainfall areas, the only major difference being that in the winter rainfall area, the pruning season runs over into August.