Purdue Urban Forestry specialist Ben McCallister recently wrote about tips for tree care as we transition into autumn and winter. These tips include mulching, fertilizing, watering, limited pruning, preventing winter trunk damage, and performing visual inspections.
McCallister said that a simple task to prepare your trees for winter better is to add a new layer of mulch, which benefits your trees in multiple ways. “Adding a 2-3 inch thick layer of mulch will better maintain moisture levels and buffer extreme temperature changes in the soil and will add some organic matter too,” he said. “Mulching to the drip line will benefit the tree the most, but in the case of larger trees it’s not always feasible.” He said to try for at least a 3-foot radius from the trunk and to make sure to leave a 2-inch or so gap between the trunk and the mulch. Volcano mulching, or piling up extra mulch around the tree trunk to resemble a volcano, is never recommended.
McCallister said that an autumn fertilization can benefit your trees, too. “Adding a slow-release fertilizer in the fall helps provide a nutrient boost over the winter, can promote root growth, and better prepare your tree for Spring,” he said. For more information on this point, access Purdue Extension’s publication on fertilizing woody plants at The Education Store, https://edustore.purdue.edu/. I might add that, given our recent dry weather, it’s probably best to wait for some fall rains before adding fertilizer.
Speaking of our particularly dry fall, watering may be more important this year than in other years. “Water is still an essential part of your tree care plan, but as temperatures drop and trees begin to head into dormancy they don’t need as much water as is required in the hot summer months,” said McCallister. “If you have irrigation systems in your yard start to drop the frequency of watering.” He said that you can water up until the first freeze, but make sure that your soils are just a little damp and not soaked. “Evergreens in particular will benefit from slow deep watering 1-2 times a week until the soil freezes,” he said. “Winter winds and temperatures can desiccate the needles without an adequate supply of water.”
While we should delay most of our structural-related pruning until late winter or spring, McCallister said that now is a good time to prune out any dead, damaged, or diseased limbs in your trees. “If you have access to hand saws and pole saws or pruners, you can remove smaller branches or those closer to the ground,” he said. “Make sure you are making proper pruning cuts though, and if there are large limbs, those at heights, or you are just unsure of how to make a good cut enlist the help of a professional arborist.”
Sunscald or southwest damage occurs on young and/or thin-barked trees in the winter, forming a long vertical split in the bark. “...these injuries can be reduced on younger trees by installing tree guards in the fall,” he said. “Tree guards are plastic barriers you place around the main stem of the tree.” McCallister recommends using white corrugated drainage pipe that can be found at most home centers. He said that you can make a cut lengthwise along the pipe for easy installation, and make sure it has a large enough diameter to leave a space between it and the tree. Remove it in the spring.
Finally, visual inspections can be done year-round, but as trees lose their leaves, it is easier to spot changes that have occurred in your trees. McCallister said that some of the things you’re looking for include fungal growth around the base of the tree, any sort of damage on the main stem or branches, premature leaf drop or color change, and branches that are dead, cracked, diseased, or seem weak. “Any concerns you find are also great information to share with an ISA Certified arborist which can be found using the Trees Are Good website,” he said.
Find McCallister’s original article at: https://purduelandscapereport.org/article/help-your-trees-transition-into-autumn/.