Parts of Illinois have been included in the Drought Monitor Map compiled through University of Nebraska in partnership with USDA, National Drought Mitigation Center and the National Oceanic and Atmospheric Administration. Considering the high temperatures in June and July along with little rainfall, our landscape plants have suffered.
We can’t change what Mother Nature has subjected us too, but we can look towards the future and think of what we can do to help our plant material survive.
A major concern is for evergreen material surviving the winter with very little soil moisture. Pine, spruce, fir, yew, juniper and arborvitae are already stressed from the summer extremes and are in real danger if they can’t pull moisture from the soil to replace what is normally lost due to winter weather. As a result, evergreens dry-up, turn brown in spring and die.
During the winter dormant season, top growth ceases. However, roots are still active until soil temperatures drop below 35 degrees. Evergreen foliage is exposed to the elements all year. Winter winds pull out available moisture and the roots need to take up moisture to replace this loss.
When the growing season is dry followed by a cold, windy winter with very little snow fall, we can expect damage. The winds blow over the evergreen foliage and suck out any available moisture. In February and March, we often have warm spring-like days. It is at these times that the evergreens try to replace moisture they have lost. If the soil is dry, the plants suffer.
In comparison, deciduous material such as maples and oaks lose very little moisture in the winter. When their leaves emerge, usually we are experiencing ample spring rain to allow for adequate water uptake.
Be pro-active and deep water your evergreens this fall. Water as much of the root zone as possible. Don’t water at the base of the trunk but water out near the drip line (the outside perimeter of foliage); more water-absorbing roots are in this area. Place a hose on a slow trickle and let the water soak in. Move the hose around the plant to ensure you are reaching as much of the root zone as possible.
Also this winter, avoid using any de-icer materials along walkways or roads near evergreens. Salt-laden runoff can restrict water uptake.
To learn more about the drought monitor, visit https://droughtmonitor.unl.edu/CurrentMap/StateDroughtMonitor.aspx?IL
Martha Smith is a horticulture educator with University of Illinois Extension. Email email@example.com