11/01/2024
Trees and shrubs still need care.
Once again, it has been a very dry fall, and central Illinois is still behind in average rainfall for the year. According to the U.S. Drought Monitor, most of central Illinois is under moderate drought (https://droughtmonitor.unl.edu/CurrentMap/StateDroughtMonitor.aspx?Midwest). One important thing you can do this fall is to make sure your trees and shrubs head into winter with substantial moisture.
You have no doubt been watering your garden areas and possibly some of your flowering shrubs, but have you been watering your trees and evergreens? If your trees go into winter without sufficient moisture, you may find dried branch tips and damaged or dead buds in the spring. Evergreens can suffer from winter burn if they do not have enough moisture. Evergreens are often overlooked because they are used as a foundation planting, and an overhanging roof can cause less rain to fall on your shrubs. Shrubs affected are junipers, yews, boxwoods, Rhododendrons, and hemlocks. Winter burn causes brown branch tips and dying to the inner shrub in the spring. Several things can contribute to winter burn. According to the University of Wisconsin extension, winter burn on evergreens can result from dry soil in the fall, drying winds, winter thaws, long periods of excessively cold weather, and intense winter sun on the evergreen foliage. Evergreens do not go as completely dormant as deciduous shrubs and trees. If there is a warm spell during the winter or direct sunlight on the leaves, especially plants on the south and west side of a light-colored building, the plant may start coming out of dormancy temporarily. The result may be the start of photosynthesizing, causing the plant to respire and give off moisture that it cannot replenish from the frozen ground. University of Wisconsin Extension shares information on watering to prevent winter burn at: https://dane.extension.wisc.edu/2022/10/20/keep-watering-in-fall-to-protect-evergreens-from-winter-burn/.
What should be done to protect your trees and shrubs as we begin November? It is suggested that you provide one inch of water a week if there is not sufficient rainfall. First, check to make sure you need to water or get an idea of how much watering you need to do. To check soil moisture, use either a moisture meter or a metal probe, like a screwdriver. Push the probe into the soil. If it meets resistance, the soil is dry. If it slides into the ground, check to see if there is wet soil on the probe. If so, there is enough moisture. Established trees and shrubs should receive one inch of water per week until mid-November or until the ground freezes. Extension recommends watering 6-8 feet from the base of the tree to 6-8 feet beyond the canopy of large trees. When watering, slow application is best. You can use timed sprinklers, soaker hoses, or a movable sprinkler. Their best recommendation is using an open hose end at a pressure that allows the greatest rate of flow that does not run off the plant area. Move the hose around the tree to cover the entire area. Doing this properly will take several hours for application, so set a timer and grab a book. details why fall watering is so important at: https://extension.illinois.edu/blogs/over-garden-fence/2021-09-20-fall-watering-important
If the tree or shrub is small and you don’t want to haul out the hose, you can fill a 5-gallon bucket and either pour very slowly or make a 1/8-inch hole in the bottom and allow it to slowly drain into the root zone. Check the moisture level and make sure you do not overwater. See UI Extension: https://extension.illinois.edu/news-releases/watering-trees-shrubs-fall-and-winter-balancing-act
The University of Nebraska-Lincoln Extension provides good general information on watering, measuring soil moisture, mulching, and prepping your trees and shrubs for winter. Fall Watering Aids Tree & Shrub Health | Announce | University of Nebraska-Lincoln This is also a good site for information on recently planted trees and shrubs. Additional links are provided within the post.
