   Deciduous Fruit Tree Pruning - February 12, 2014 Jeff Schalau, Agent, Agriculture & Natural Resources University of Arizona Cooperative Extension, Yavapai County Deciduous fruit trees benefit from yearly pruning throughout their productive lifespan. However, it is difficult to describe the pruning process in writing. Each tree has individual characteristics that make it nearly impossible to generalize. In addition, there are multiple approaches, most of which are valid and dependent on individual preferences. I’ll do my best to provide theoretical information in the remainder of the column, and then invite you to the free pruning demonstrations that I conduct each year. At these demonstrations, you can watch and ask questions as we discuss the principles of deciduous fruit tree pruning. Pruning is critical to maintaining deciduous fruit tree health and productivity. Pruning also creates a desirable structure for supporting the fruit crop and can keep the tree a more manageable size. That being said, no pruning should occur without good reasons to do so. Winter pruning often causes a tree to respond vigorously (especially on apples and pears), often too vigorously, in cases when large limbs are removed. Conversely, summer pruning does not cause as drastic a growth response and is often used to remove materials without initiating as much regrowth in the form of less desirable water sprouts. Some fruit growers prefer trees that are trained to a central leader. This strategy is most often used with apples and pears and requires removal of unwanted branches from the trunk while leaving behind strategically spaced side branches (scaffold branches). Open-center pruning removes the central leader at a very young age (preferably right after planting) to encourage the tree to spread outward from the trunk allowing light to penetrate and air to circulate in the center of the tree. Open-center pruning is commonly used for stone fruits (peaches, nectarines, plums, apricots, and cherries). I also prune my apple trees to an open center to keep them dwarfed and easier to harvest. Some pear varieties just grow straight upward and will tend toward a central leader regardless of pruning. All trees, whether fruit or ornamental, should be pruned to remove crossing and inwardly growing branches as well as dead and diseased wood. Sometimes fruit trees have been neglected for multiple years and require extensive pruning. In these cases, I recommend addressing the most crucial problems first and leaving the less important issues for summer or next year. As a general rule, you should not remove more than one-quarter to one-third of the canopy in any given year. Peach and nectarine trees are an exception to this rule and can be pruned more aggressively due to their vigorous growth and tendency to die back when branches are shaded or too dense. Most apples and pears produce fruit on spurs: shortened twigs where flowers are produced. These spurs usually become productive at 3 years of age and can continue for 10 years. Plums, apricots, and cherries produce fruit on shorter-lived spurs. Peaches and nectarines produce fruit predominantly on the previous year’s wood. This is critical when planning your pruning strategy for each of these species. Large pruning cuts should be kept to a minimum. These cuts take longer to heal and will often cause water sprouts (vigorous vegetative shoots) to grow in that vicinity during the following growing season. If you must make large cuts, do not use a pruning sealant or wound dressing. Simply allow the cut to callous over naturally. Finally, use only clean, sharp pruning tools. Soak the loppers and hand pruners in rubbing alcohol for 5 to 10 minutes between trees and especially after pruning diseased material out. Now, I’d like to invite you to attend one of my fruit tree pruning demonstrations. I will be conducting these at: the Marmaduke Orchard, 3435 S Silver Rd, Camp Verde (off Salt Mine Rd) on February 22, 2014 from 10 am to noon and the McLandress Orchard, 850 S. Maricopa in Chino Valley on Saturday March 15, 2014 from 10 AM to noon. For maps and directions to these demonstrations, visit the Yavapai County Cooperative Extension Web Site at: cals.arizona.edu/yavapai/pruning. I will also post notice of any cancellation due to weather on my Twitter feed (@jeffschalau) at twitter.com. If you have other gardening questions, call the Master Gardener help line in the Camp Verde office at 928-554-8999 Ext. 3 or e-mail us at verdevalleymg@gmail.com and be sure to include your name, address and phone number. Find past Backyard Gardener columns or provide feedback at the Backyard Gardener web site: http://cals.arizona.edu/yavapai/anr/hort/byg/.  |