As the green leaves that shaded us all summer begin to wither and fall, it’s time to start preparing your trees for winter to set them up right for the following spring.
Say “autumn” and most people think of the dramatic reds, oranges, yellows, and rusts of fall foliage. What may surprise many is that not all trees put on a glorious display; in fact, some trees can be completely devoid of color. Those lucky enough to have a maple, dogwood, shagbark hickory, tricolor beech, or quaking aspen should get ready for a spectacular show.
For the rest of us, be sure to check out the suggestions for brilliantly colored trees that follow. If the trees in the ground still have leaves, check the soil temperature. If it’s 50 degrees Fahrenheit or warmer and expected to stay that way for six to eight weeks, then new roots can get established, and there’s still time for a fall planting.
The Science of Pruning
Annual tree trimming serves two purposes: good looks and health. Dead, diseased, or unsafe branches can be trimmed off any time of year, but most definitely in the fall so that they don’t come down all on their own because of winter snow and wind. Trim them close to the trunk (leave no stub) and leave the wound exposed to heal naturally.Major corrective pruning, on the other hand, which is designed to maintain the overall health and shape of the tree, shouldn’t be done in the fall. It’s best done in the winter months when most pests are also dormant or in the spring just before the tree begins to leaf out, as the new growth will help the tree seal off the wound more quickly. The exceptions are fruit trees; some gardeners swear that trimming them after the harvest in summer or fall results in an increased yield. The theory is that this pruning stimulates new growth, resulting in a healthier, more productive tree next season.
Not all questionable limbs need to be trimmed for the winter. Some large limbs or even entire trees (particularly those that are right next to the house) that you want to save can be given additional help in the form of a cable or brace that will help them resist the weight of ice and snow. Dynamic cabling uses flexible, elastic cables that allow movement in the wind, while static cabling uses strong steel cables to secure against any unwanted movement. If there’s any question, consult a professional arborist.
Clean and Well-Fed
Clean up the area around trees to avoid the mold that can form on damp piles of fallen leaves covered by snow. Keep an eye out for mushrooms at the base of a tree; these can be a sign of root decay. Don’t overwater trees, particularly in winter, as fungi love moist conditions. Without the beating heat of summer, soil will naturally remain moist longer, meaning irrigation should be reduced and can even be turned off in many cases. Add a layer of fresh wood mulch or straw to help conserve moisture, maintain soil temperature, and protect against soil erosion or compaction.While mature trees in nature usually don’t require fertilizer, home specimens can benefit from it, especially those planted in the past few years and those that are surrounded by wood mulch that uses nitrogen as it decomposes. Most homeowners rake away the fallen leaves that, in a forest, would be left to decompose and nourish the soil.
Pro tip: Don’t throw away that pile of leaves! Instead, spread them out on the lawn and run the mower over them to dice them into an organic winter leaf mulch for the lawn. Diced leaves decompose faster and are less susceptible to mildew.
Trees focus on root growth in the fall, using them as a storage bank for the nutrients that will be in high demand come spring’s new shoots, leaves, and flowers, resulting in a stronger, sturdier, and more durable specimen overall. Avoid high-nitrogen fertilizers in late summer (late August through mid-September), as these can result in an unwanted flush of new leaves that are vulnerable to frost damage.
Wait until the tree has entered dormancy—leaf drop is a good clue. Then fertilize with a slow-release fertilizer designed for trees that mimics the nutrient release of nature. Don’t fertilize during a drought, because it can scorch the roots, and never apply fertilizer to frozen ground, as it simply won’t work.