When is the right time to prune a maple tree? How much should I take off when pruning an apple tree? Where is the right spot to make the cut? And when should I call a professional arborist?

These questions and many more were discussed at a recent workshop hosted by the Upper Big Blue Natural Resources District and Nebraska Extension. Nebraska Extension Educator Sarah Browning was the speaker, presenting Mastering the Basics of Tree Pruning. Browning is a certified arborist with the International Society of Arboriculture and a member of the Nebraska Arborist Association. She has been a speaker for several previous workshops hosted by the NRD on topics such as vegetable gardening and fruit tree care.

Browning had a lot of advice for the workshop attendees:

• When it comes to pruning trees, timing is essential. Pruning wounds close fastest when shade trees are pruned late during the dormant season, February to March, but pruning can be done anytime from November to March. For fruit trees, the best time to prune is right before the growing season starts, February to March.
• Your strategy for pruning will differ depending on the type of tree and your goals for that tree. Are you pruning to remove diseased and dead limbs? Shape the growth and height? Prevent damage, or maximize production? There are many variables to consider.
• Never remove more than 10 to 15 percent of the plant’s canopy in one year. If you need to remove more than that, wait until the following year before you prune more to give the tree time to recover.
• Heavy pruning is not recommended at planting or transplanting. The stress of getting established plus recovering after pruning will be very hard for the tree.
• A rule of thumb to follow for establishing good tree structure is to aim for two-thirds canopy and one-third trunk. This proportion of canopy to trunk ensures the tree has a good mass of foliage, which is the tree’s “factory” for photosynthesis and creating its energy resources. Keep this guideline in mind when removing bottom limbs.
• Don’t make flush cuts on a tree’s trunk. Always make cuts at a slight slant away from the trunk and outside the branch bark ridge and branch collar. (See photo below)
• Look for multiple leaders of approximately the same size developing in the tree – called co-dominant leaders. These joints are often weak and can lead to branch or trunk failure in the future. It is important to manage co-dominant leaders when pruning to develop strong tree and branch structure.
• The biggest rule in tree pruning is NO TOPPING! Topping occurs when flat cuts are made to large branches at random. Excessive sucker development typically follows topping cuts and the entry of wood rot decay, too. Think of topping as “a bad haircut that can kill you,” said Jay Seaton, forester with the Nebraska Forest Service who also works with the Upper Big Blue NRD.
• On fruit trees, a bit of pruning every year is better than a huge job every few years. Browning suggested that increasing light penetration throughout the tree’s canopy will result in better fruit production. Follow the guideline of no more than 10-15 canopy removal in one year for fruit trees, too.
• Not sure where to start on old, neglected fruit trees? On your first pruning, take out damaged or diseased branches first, plus suckers around the trunk or unproductive “sprouts” on the branches. The following year, get more aggressive with removal of unproductive branches and opening up the center of the tree to increase light penetration. 

See the slides from Browning’s presentation on the NRD website at www.upperbigblue.org/projectgrow (click on 'Workshop Resources'). For more information, visit Pruning Fruit Trees, https://extensionpubs.unl.edu/publication/ec1233/pruning-fruit-trees-ec1233.