|URBANA, Ill. — Late winter, February to March, offers the optimal time to prune apple trees, said a University of Illinois Extension horticulture specialist.
“Pruning is the judicious removal of apple shoots, branches, and spurs,” said Maurice Ogutu. “Major pruning is done during the dormant season before the bud break. In February and March, there is much less risk of winter injury.”
Apple trees need to be pruned every year to keep the tree at the desired height for ease of management and harvesting. Pruning also improves air circulation and light penetration in the trees.
“Apple trees that are pruned every year produce higher yields and good-quality fruit,” he said.
Trees are pruned based on the age of the tree, the training system used to attain desired framework or maintain the existing framework, fruiting habits of the variety, and whether the bark and wood is damaged or not. Pruning can be done by simple equipment such as hand shears for removing small shoots and spurs, lopping shears for removing larger shoots and small branches, and pruning saws for removing larger branches.
“Use sharp tools and make clean and smooth cuts, which heal much faster than rough and ragged cuts,” Ogutu recommended. “Pruning can be done by either heading-back to encourage growth of side branches or thinning-out to remove unproductive branches in order to increase light penetration or to shorten a branch.”
He suggests the following guidelines for pruning newly planted and mature trees:
•At planting time, unbranched trees sometimes called whips can be pruned to 30 inches above the ground. Prune roots that are too long or dead before planting. Trees that are two years old or more tend to have branches, so you can select branches with wider crotch angles, spaced evenly around the trunk, and 18-to-22 inches above the ground;
•After the first year’s growing season, select two to four branches, remove other branches, and cut back the main leader to 15 to18 inches above the crotch of the highest branch. Use branch spreaders in branches with narrow-angled crotches;
•After the second, third, fourth, and fifth-year growing seasons, select one, two, or three branches every year. Head-back the leader every year as in the first year - standard trees may require more severe pruning than dwarf or semi-dwarf trees. Continue pruning after sixth to 10th year growing seasons to complete the desired framework for the tree by heading-back and thinning-out when necessary;
•Mature trees need to be pruned every year in order to achieve uniform light exposure and to facilitate renewal of bearing wood. When pruning mature trees, you can follow these steps: start by cutting upward-growing limbs; remove crowded branches by starting from the tips of the branches and pruning to the base; continue pruning as you move downwards by removing dead, broken, and diseased wood as these areas harbor disease pathogens and insect pests; shorten any crossing branches, or parallel branches, and branches lying on top of another or very close to the ground; water sprouts except where you want to fill a vacant space in the tree; and suckers that grow from the base of the trunk.
This farm news was published in the February 22, 2006 issue of Farm World.