DEAR NONNO, I'VE HEARD THAT IT'S IMPORTANT TO PRUNE FRUIT TREES, BUT AM AFRAID TO TRY. HELP!
-Liz (New Mexico)
Thanks for your question Liz.
Edward Scissorhands has been both a good and bad influence on the world of tree pruning. Stylistic pruning, while inspiring, does not translate particularly well in the world of fruit trees. Making something look "good" and getting the most from a fruit tree are rarely the same thing.
The most basic concept of pruning is that by cutting back a tree, it will promote new growth. Accordingly, new growth encourages more fruit production. The next idea is to determine shape. Rather than sculpting rabbits or fairies, the shape of your trees need to be better geared for production purposes. It should be strongly defined with good airflow.
Whether you are after a tall slim tree or a short wide one, it is where you cut along the branch that will determine whether the plant grows out or skyward. Firstly, always prune at a bud junction. To encourage the plant to grow tall, cut at the bud that is heading skyward. To encourage the plant to branch out, cut where the bud is pointing sideways.
Timing... when to prune your fruit trees? There are a couple of differing opinions on this, but one thing we can all agree on is that it's not immediately after watching Tim Burton movies. Rather, prune after the tree has fruited. That means once a year for deciduous (apple, pear, stone fruit, etc.) and some evergreen, but citrus that fruit twice a year can do with two rounds.
Remember that most deciduous fruit trees develop fruit on new growth, therefore, seasonal pruning is essential for fruit production. If you have a tree that is still establishing to full size, trim back last year's growth about 25-50%. This will allow for new fruit, but still an overall gain in tree mass. For trees that are full size, cut back most of the previous season's growth.
For citrus, which suffer from the gall wasp, you'll need to be more strategic. Rather than pruning out every new piece that you come across, make a concerted effort every few years to eradicate the diseased branches. Citrus can live with gall wasp but over time it does effect fruit production. A plant cut back every few years will outperform one that is cut back every few months.
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