JoAnne Skelly: When is the best time to prune fruit trees?

I’m often asked when the best time to prune fruit trees is. I pruned my crab apple and apple trees last week. I chose this time of year to prune them, not because it was optimum season for pruning, but because I couldn’t stand looking at all the ugly water sprouts (vertically growing small branches) sticking up haphazardly throughout the framework of the main branches. I see these trees from my kitchen window every day.

Is there an optimum time to prune fruit trees? One author out of North Carolina Cooperative Extension states that pruning during dormancy encourages too much vegetative growth over fruit development in the spring. He went on to say a second pruning toward early summer would then be necessary to remove the excess growth, particularly the water sprouts. A Utah Cooperative Extension Master Gardener recommends pruning after the last freeze of winter, but before full bloom in the spring. University of Nevada Master Gardener Michael Janik, who is a fruit tree expert, usually advises summer pruning. A Utah State University horticulture specialist recommends that mid-summer is the best time to prune water sprouts because they will be less likely to grow back.

I may have pruned my crab apple at the worst time, since I’m trying to avoid the darn water sprouts and suckers (vertical shoots from the roots). However, I can’t believe that they won’t grow back even with a mid-summer pruning. I’ve tried every time of year and they always grow back.

Since one of the primary reasons for pruning fruit trees is to encourage fruit production, and since fruit develops best on year-old wood rather than older wood, old wood needs to be removed to allow new wood to develop. Branches cut this year will produce fruit next year.

Fall, after a hard freeze or two, is an excellent time to prune evergreen trees. Bark beetles and borers will be dormant and not likely to attack a freshly pruned tree. Shade trees are often pruned in late winter or spring. However, during spring growth, bark is tender and easily damaged, so extra care is needed to avoid injury. In Northern Nevada, we generally prune maples, birches, beeches, poplars, elms and willows in the fall to minimize the extensive sap loss these trees experience if pruned in the spring. Sap loss can be a significant stress factor in our arid environment. For other trees, pruning in fall may allow pruning wounds to be more easily infected with decay organisms.

JoAnne Skelly is Associate Professor & Extension Educator, Emerita at University of Nevada Cooperative Extension. She can be reached at skellyj@unce.unr.edu.