Thoughts may not naturally gravitate to pruning fruit trees in February, but they should – especially this year! Thanks to above-average temperatures for much of the winter season, fruit trees in Central Illinois are showing signs of waking up early. So, like it or not, it is time to get out there and prune.
Pruning fruit trees is one of the easiest ways that orchardists can prevent disease, boost yields, and decrease insect pest pressure, not only for the hobby grower but the commercial farmer too. This is done by making specific cuts on the tree with particular tools that will increase airflow, even out sunlight penetration, and improve fruit tree shape for ease of harvest. These principles can be applied to more commonly planted fruit trees like apple and pear, but are also applicable to other species, like plum, sour cherry, pawpaw, persimmon, and even nut trees.
When selecting tree fruit wood that should be removed to achieve the above goals, there are easy decisions, and hard ones too. Easy candidates for removal include branches that cross each other, branches growing in a downward direction, or wood that appears damaged, dead, diseased, or dying. Suckers – new growth originating from ground level or low on the main tree trunk – should always be removed.
If some convincing is needed, here are some potential consequences that can result from lack of annual fruit tree pruning.
Fruit tree growth per-year can be prolific and lead to lots of new growth in just one season. Too many crisscrossing branches in fruit trees can increase canopy humidity and make fungal and bacterial disease much more likely. We remove these to increase the dry-out of leaf surfaces, leading to better disease resistance, increased photosynthesis, fruit set, and harvests.
Damaged, diseased, or dead tree limbs can be used as entry points for insect pests and diseases. If diseased tree tissue remains on a tree or even on the orchard floor throughout several seasons, disease pressure can explode – even if the grower uses integrated pest management strategies.
Some growth might look healthy, but it’s just growing in the wrong direction – downward. Fruiting spurs (the tips or main, fruit-bearing buds of trees) and fruiting branches they reside on should be horizontal. Downward facing fruit wood, especially on heavier fruit like apple, peach, and pear, may cause weaker branches to break as the fruit increases in size near harvest time.
Note: when pruning fruit trees, no more than 1/3 of the tree’s wood should be removed, according to many State Extension fruit tree management resources. However, removing 1/4 of fruit tree wood is better yet. If fruit trees have not been pruned in many years, removing the above-described tree tissue will likely take orchardists to this annual pruning limit.
Do NOT exceed the 25-33% limit – your tree will make “water sprouts” – large, usually upright, vigorous branches on your fruit trees. Water sprouts are bad news for several reasons. First, they grow only vegetatively – producing lots of leaves, but no fruit. Second, they add lots of wood to your possible pruning selections for the following pruning season! They are undesirable, so many will prune them off, but sometimes the removal of all water sprouts a season after a heavy pruning will total about 25% of the fruit tree’s wood and limiting the ability of the grower to prune off any other wood for another year.
Tools of the trade, proper cuts, sanitation of pruning tools, and how to shape different tree fruit species with pruning cuts all warrant a second article on this topic. Or instead, come to the University of Illinois Extension’s hands-on pruning workshops at the Refuge Food Forest in Normal, IL on Wednesday, March 4th and/or Thursday March 16th, from 4:00-5:30PM. No matter your pruning skill level, come try out your tree fruit pruning skills on someone else’s fruit trees so that when it is time to prune yours, you know what you are doing. Contact me (Nick Frillman) at frillma2@illinois.edu for questions about how to register for our free workshops.