Tips on pruning for more healthy and colourful plants
AFTER a hot summer with lots of rain, it’s time for pruning.
Usually the best time for pruning flowering bushes and shrubs is just at the end of flowering, to make sure they will flower again the next season.
Some plants are more forgiving in that respect than others. Chinese lanterns, for example, won’t flower the next year if you are too late. Other plants might flower just a little if you have pruned them too late.
The best time to prune fruit trees is after harvest. Some trees still have fruits and start flowering again, which makes it a bit difficult. You in a way have to cut all the unwanted growth without disturbing the new flowers too much.
One type of pruning is called tip pruning. If done regularly, you promote lateral growth and you will get a much bushier plant. It is best to start tip pruning when the plants are very young and to prune the tips after flowering because it will result in an increase in flowers. In general, if you don’t prune the old flowers the plant will use all its energy for seed production and not for growth of new flowers.
Another reason to prune is to control unwanted growth. You might need a clean and sharp hand saw to cut little branches. It’s best to make clean cuts at a 45 degree angle and close to nodes. And, when cutting larger branches start cutting the bark below before cutting from the top to prevent tearing of the bark.
Some plants – like many of the leptospermums, melaleucas and hakeas – flower on old wood. If you cut into old wood you might lose flowers the next season.
Another reason to prune is to repair damage. Broken branches or branches attacked by borers should be cut back to undamaged wood immediately. If there is a borer you can see a little hole in the branch. You just cut until you can’t see this hole any more. If you leave it too long and the hole goes too far into the centre of the tree, you have to try to kill the insect, which is best done with some pyrethrum, a herbal insecticide. If you just leave the broken or damaged branch, you risk an infection.
Through pruning you can also keep a plant young and fresh. If you always cut old trunks straight at the bottom or as far down as you can, you promote fresh growth. If you have a shrub which was not touched for ages, don’t cut everything which seems old; cut maybe a third, and next year cut more.
Plants like roses you can cut the whole year. Always cut the dry wood and of course the old flowers to avoid the rose going into seed production, because you want the flowers not the seeds. Same with strelitzias. If I have to cut the old flowers of a giant bird of paradise I cut the whole stake from the bottom. But be careful – they are often full of water and very heavy.
So have fun rejuvenating your garden and make sure your cutting tools are sharp and clean because it is easier to work, the cuts are straight and it is better for the plants.
DIRK’S WORDS OF WISDOM
> If you have a hedge of, for example, lilly pillies, acmena or syzygium, and they look a bit stalky or they are not bushy to the ground, trim them and they will shoot again.
> Hedges in general should be trimmed at least once a year. If you have a flowering hedge or you used plants with beautiful new shoots, cut it just before it starts shooting or flowering.
> In case you have any old shrubs or bushes that are an eyesore you can cut them as low as possible to promote new growth. If you do it just before the growing season, they will start shooting very fast and in no time you could have a new healthy shrub. It usually works very well with callistemons, fine-leaved melaleucas and leptospermums.
Dirk is available for advice on residential gardens as well as acreages. You can contact him by phone, 0429 020 215, or by email, Dirkuhagl@hotmail.com