Lack of regular, moderate pruning is one of the most common causes of low or no fruit production. On the other hand, removing more than a third of the tree could have the same effect on fruit production, stimulating the growth of branches instead of fruit.
There are three main reasons you should prune your cherry tree: its survival, stimulation, and shaping. However, it’s not necessary to thin the fruit, since cherry trees do this on their own.
For survival, pruning helps balance the top growth of your tree with the root system, which loses many of its fine feeder roots during transplant. It gives the roots time to re-establish themselves.
For stimulation, pruning stimulates stronger, more vigorous growth from remaining buds. A pruned tree will be bigger, with stronger branching, than an unpruned tree.
Shaping the tree gives it the structure it needs for maximum fruit production, with adequate space for air circulation and sunlight penetration.
You should prune your tree twice a year. Start in early spring before buds break but after threat of a cold snap. (In zone 6 and north, do this in late winter.) Make the shaping cuts that remove limbs and large branches. Prune sweet cherry trees to a central leader that encourages scaffold development to support the canopy and keep the fruit from becoming overexposed to the sun and other elements.
For sour cherry trees, go for more of a modified central leader and a vase-shaped or open center structure, to provide light penetration and air circulation.
This pruning is also aimed at providing the tree with a few strong limbs for bearing fruit, instead of many weak limbs that can’t support the weight of fruit.
Prune a second time in late summer. This pruning is intended to clean up the canopy and increase air circulation as a preventive measure protecting against fungal infections. Instead of shaping the tree, you’re only opening things up with a few cuts.
Above all, if you keep up with your pruning, you’ll have a healthier tree and also a less labor-intensive task each time you prune, involving small, easy-to-heal cuts.
Sometimes you have to prune outside the normal schedule. If a branch is broken by the wind or by a heavy load of fruit, you’ll have to take emergency action. You want to prune to clean up ragged edges, making a flush cut that leaves no stub. Damaged, dead, or diseased limbs, or suckers, should all be removed as soon as you see them.
Please tell us about your cherry pruning techniques. Have you faced any challenges with pruning your cherry trees? How have you handled them? Please comment below and share your experiences.