Dealing with Fall Drought in the Home Landscape

Posted by

"The cracks in my yard have cracks," I recently heard a colleague remark. In Central Illinois, spring and fall typically bring reliable rainfall. Dependable fall and spring precipitation is why we say these are the best times of year to plant trees in our region.

Fall of 2017 is off to a dry start. There has been little significant rainfall in the past month, and we experienced a string of high temperatures these past few weeks. At this time of year, our cool season lawns should be growing annoyingly fast. My mower should be cutting the lawn at least once, if not twice a week. In the last five weeks, I've mowed my lawn one and a half times. The "half mowing" occurred last weekend, when I fired up the mower to cut some newly seeded patches of turf that I have been watering.

Late summer to early fall is also a good time to overseed, renovate, or start a cool season lawn. Again, the fall weather, which normally brings cooler temperatures and some rain, is ideal for cool season turf grasses. This year, if you are not irrigating newly seeded lawn, it likely will not successfully establish and survive the winter.

Cool season perennial lawn weeds (think dandelions, clover, plantain, and many others) are best treated in the fall as they are often actively growing and preparing for winter. Actively growing plants readily take up herbicide that translocates to the root system and kills the entire plant. Thing is with the hot, dry weather our cool season weeds are not actively growing as normal. Therefore, herbicide applications will be less efficient. Our window for treating lawn weeds closes about mid-October, and we may still be in the same situation as we are now.

Evergreens are another landscape plant where fall precipitation is critical. By holding their foliage through the winter, evergreens continue to lose water, unlike their deciduous counterparts. Frozen winter soils do not permit evergreens to replenish that loss of water. Evergreens going into winter after a droughty fall run the risk of severe winter burn of foliage, stress, and perhaps the outright death of the plant.

The Takeaway

Following are important tips when dealing with fall drought:

  • Water newly planted trees, shrubs, and perennials. Trees especially take a long time to become established, which can be upwards of two years depending on the species and site conditions. A plant without an established root system is highly susceptible to drought stress.
  • Evergreens both newly planted and established require irrigation during a fall drought. Leave a dripping hose at the base of the evergreen for several hours at least once a week. A five-gallon bucket with holes drilled in the bottom does the same trick.
  • For those desiring a high-quality turf, irrigating in the fall will provide the necessary moisture to keep the lawn green and actively growing. Apply about an inch of water per week.
  • Mulch is a great technique for insulating the soil from temperature extremes and conserves moisture. Two to four inches of wood chips are adequate. (Aside: Mulch should NEVER touch the trunk of a tree or shrub.)
  • Irrigate fall blooming plants. Drought reduces the flowering of fall blooming plants and pollinators need that critical nectar source this time of year.
When it comes to the weather, I wish there was a crystal ball to tell us exactly when the rains and cooler temperatures will return. The best we can do are weather computer models for predictions. As of now, the models suggest temperatures will cool to more seasonal levels, but we will remain dry. There is no significant rainfall in the long-range forecasts until November. By then it will be too late for our lawns, and depending on how low the temperatures get, may be too late for our evergreens.