It's time: Prune fruit trees soon
Carl Hoffman, my coworker in Stearns County, brings us this week's timely tip. Many of us have fruit trees that are often neglected, but hopefully, this article will motivate those of us that need a little encouragement to put those pruning shears to work.
Late winter to early April is the best time of the year to prune fruit trees. Dormant pruning of fruit trees minimizes the possibility of fireblight in crabapples, apples and pears as well as canker diseases in cherries and plums. Pruning too early in the winter, however, may result in winter injury and branch dieback.
When pruning, it is important to use strong, well-sharpened tools. Pruning equipment will last for many years if properly cared for; making an investment in good quality tools a wise choice. A home gardener needs three basic pruning tools; a pair of lopping shears, a pair of pruning shears and a good pruning saw. It is important to use tools made specifically for pruning and to keep them sharp and clean.
When pruning the trees, start by cutting out broken, dead or diseased branches. Cut out all thin, weak wood and remove any surplus branches so that light can penetrate and air can move freely through the tree. This will allow the fruit to color well when it ripens and facilitates easier harvesting.
The free movement of air through the tree will curtail the development of fungus diseases, especially sooty blotch and fly speck. Remove branches that have narrow, weak crotches and cut back any branches that droop from the weight of a former fruit crops.
When heading back branches, it is important to cut just before a bud on the upper side of the branch so that the branch that develops will grow upward rather than downward. Remove waterspouts, which are those succulent, vigorous shoots that grow straight upward on the inside of the tree. These watersprouts are heavy users of water and nutrients while producing small amounts of fruit. If there are co-dominate leaders, those branches competing to be the tallest, remove all but one of them.
When removing a branch or shoot from a tree, make cuts close to the trunk or branch from which it is being removed. Make the cut as close as possible, but just outside the branch collar, so that stem tissue is not injured and the wound can seal in the shortest possible time. The branch collar is the wrinkled or swollen area around the branch where it attaches to the trunk or another limb.
Flush cutting will impair the production of new tissue and the wound will heal slowly. Never leave stubs, as they encourage rotting into the heartwood of the tree. To prevent torn bark and wounds when removing larger branches, first undercut the branch about half way through at a foot from the trunk. Then cut from above at a point an inch or two from the undercut and, finally, cut off the stub that remains.
If an older tree is too tall for convenient spraying and harvesting, the height of the tree can be lowered by completely removing one or two of the tallest growing limbs. Make the cut where the limb joins the trunk.
It is important to remember that you should never remove more than one-third of the wood in any one year. Therefore, if you want to prune a tree drastically, spread the pruning over a period of three years. Never, under any circumstances, top a tree by removing all the branches. Over-pruning stimulates sucker type growth and lowers both the strength of the tree and fruit production.
It is not necessary to use a pruning sealer or wound paint when pruning is done at the proper time. In fact, the use of these products may actually retard the proper healing of the pruning wound.
To get our free publication, Pruning Trees and Shrubs, check us out online at the Web site, www.extension.umn.edu, or contact me at 800-450-2465. If e-mail is your thing, contact me at email@example.com.