Summertime is cutting time, especially for cherry, peach, nectarine and Japanese plum trees.
USUALLY, THE BEST time to prune fruit trees is after they have dropped their leaves and are dormant in winter. There are, however, definite advantages to pruning fruit trees in August. It’s the best time to prune stone fruits such as cherry, peach, nectarine and Japanese plums, because cuts made on these trees during our rainy winters are highly susceptible to bacterial diseases that can cause branch dieback.
For all types of fruit trees, August is a good time to remove dead, damaged and diseased limbs to prevent them from spreading harmful spores during the rainy winter season. It’s also the perfect time to do light thinning by removing shoots that are crowding the center and top of the canopy. Thinning out unproductive shoots will improve air circulation and allow increased sunlight to penetrate into the tree.
Increased air circulation will help prevent fungus disease. It also will open the canopy to allow increased sunlight to reach the fruit, which speeds ripening. While thinning shoots in the top of the canopy, it’s a good time to control for height by cutting upright growing shoots back to lateral stems farther down on the branch.
Thinning out unproductive sprouts in August also reduces shoot growth the following spring. That’s because in fall, when the leaves turn color, lots of carbohydrates are transferred from the foliage into the tree to be stored in the trunk and roots. All of that stored energy stimulates vigorous sprout growth the following spring. August pruning reduces the number of leaves available to transfer energy to be stored in the tree and, in turn, generally decreases shoot regrowth in the following spring.
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There are a few guidelines to follow. Perform summer pruning only on vigorous trees with strong growth. Removing foliage from a tree with reduced vigor will only weaken growth further. Even on a robust grower, don’t overdo it. Confine pruning cuts to thinning out unproductive sprouts that are crowding and blocking air and light from penetrating the canopy. Take out no more than 10 percent of the canopy in the process. Removing too much wood could inhibit next season’s fruit production.
Except for stone fruits, wait to do heavy-duty pruning, such as height reduction and removal of large limbs, until the tree is dormant in winter. As a general rule, dormant trees can withstand removal of 30 percent of the canopy without affecting fruit production.
Make sure to complete all summer pruning by the end of August, before the leaves begin to turn color, in order to prevent interfering with the energy-transfer process.
Finally, if you’re wondering how to prune a heavily laden fruit tree without knocking off the fruit, it’s all about patience. If you’re careful, take your time and work from a ladder, it’s usually not that difficult to prune without dislodging much, if any, of the fruit.
It’s a different story if you hurry, though. I learned that lesson one August morning, after I received a call from my TV partner, Meeghan Black. She told me she and the film crew would arrive at my house in about an hour to film a show on summer pruning, and to remind me that I promised I’d have one of my pear trees pruned before they arrived to show what the completed project should look like.
Needless to say, I’d forgotten all about it. Determined to get the job done before they arrived, I grabbed my ladder and pruning tools and ran for one of my heavily fruited trees. I worked at a fevered pitch, and somehow managed to complete the job just as they drove up. Other than the fact that there were only three pears remaining on the tree, it looked great!