Pruning apple trees: how to do it right
By LEE REICH
Even if the apple tree you planted a few years ago has grown full size, annual pruning is still needed to keep it healthy and fruitful. And the best time to prune is anytime from late February until the flowers open.
Start pruning by removing diseased, dead and broken branches. Dead or broken branches heal poorly, so they could provide entryway for disease. Dead branches are easy to spot because they are shriveled and their buds remain lifeless while healthy buds on the tree are swelling. Cut back dead or broken branches to healthy buds. Cut diseased branches a half-foot back into healthy wood.
Next, prune back some larger, albeit healthy, branches. Do this to offset the natural tendency for upper branches to grow most vigorously and to shade lower ones, and because you may need to keep your tree within bounds either in height or spread. To minimize regrowth, cut these branches back to their origins, or to match the lengths of weaker-growing side branches.
Avoid stripping bark when sawing off a large limb by first shortening the limb to about a foot, undercutting slightly before sawing from above. Then saw off the rest of the limb, up to the slight collar at the base of the limb, to promote good healing.
The best fruiting stems on an apple tree, in terms of productivity and fruit quality, are those that are moderately vigorous and growing horizontally off major limbs.
Water sprouts (suckers) are overly vigorous, vertical branches that not only are unfruitful and produce poor-quality fruit, but also shade the interior of the tree. Remove water sprouts right at their bases. If your tree has been neglected for many seasons and there are many water sprouts, do not remove all of them in one season or else the interior of your tree, suddenly exposed to sunlight, will sunscald.
At the other end of the spectrum in vigor are stems that are too weak to fruit well. Invigorate young, weak stems by shortening them, which stimulates growth from buds just below cuts. Shorten long, old drooping stems to side branches growing in near-horizontal positions. Twiggy stems growing off the undersides of limbs are particularly weak; remove them.
The final stage in pruning is to work on the spurs, which are the clusters of fat, stubby stems that actually bear the fruits. With age, apple spurs become weak and overcrowded. Invigorate individual spurs by shortening them back to strong buds. Where spurs are overcrowded, remove some so that fruits will be evenly distributed, but not crammed, along the branches of your tree.