How to reduce the height of fruit trees
At the community garden, we want to bring down the height of our fruit trees so that none of us need climb a ladder to pick the fruit. Gone are the days of leaving some for the birds, as we now need to remove any fruit that could be infected with Queensland Fruit Fly. Fruit high up is quite a danger to our hygiene strategy. Lowering trees also makes it easier to net them which will be essential to exclude fruit fly from now on. Making a specific pruning cut is the way to do this.
When a heading cut has been used, the tree height will have been lowered by cutting off all the apical or terminal buds. Essentially the main branches are cut to one height. The result is that 3 or more buds immediately beneath the cut on each branch develop en masse, producing a spike of new growth that quickly shoots upward. You are then back to square one with a tall tree, and as a corollary, no fruit the next year.
Remedying this is easy and requires developing horizontal branches rather than vertical ones, using thinning cuts. Beginning with one main branch, select the junction between the main branch and a lateral with an apical bud. (You are looking for a horizontal side branch off a thicker main branch that has a bud at its end).
Cut the thicker, main branch just above the junction. Now the lateral with its apical bud will become the new leader and will be horizontal or slightly at an angle (sometimes angled upward, sometimes downward). Continue pruning section by section until the tree is fully pruned.
The result within several months, is that the reshaped tree will produce shoots lower down the tree and these can be developed or thinned as you see fit. Shoots that face inward can be pruned out to keep the centre of the tree from being congested and to create good air circulation. Where several shoots appear together, select the strongest that is in the direction you want and prune out the weaker. See the photo opposite of an apricot tree to which we have applied this pruning technique.
Related articles
Pruning: Thinning vs heading cuts
Microwave your Queensland Fruit Fly infected fruit
Written by Robin Gale-Baker