Early September typically brings cooler temperatures and enough rain to green up our lawns and keep them green until cold weather shuts them off for the 2017 growing season.
So far, we have had the right temperatures, yet the rains have remained very scattered and the amounts very limited. Long term, this concerns farmers and horticulturists since we need to have the soils recharged with water as winter approaches. Short term, for the farmer, it means crops will be shutting down early, which will limit yields and possibly the grain quality as well.
Homeowners also are concerned since this is the prime time for properly establishing or repairing lawns from disease, insect and weed damage. Grass seed needs an evenly moist soil from germination through that first mowing for sure, ensuring a mature grass plant for winter survival. Any herbaceous perennials to be moved need rain to help them through the transplanting process. Given our current situation, perennials should be well-watered before being moved and watered regularly after the move to give them the best chance to survive the winter. As a bonus to the gardener, moist soil is easier to dig through than a hard dry soil.
Fall is a great time for planting trees and shrubs in the home landscape. We always 'water in' well at planting time and that should be good for about a week and then watering to keep the balled and burlapped tree or container grown shrub well-watered through late fall is essential. If the holes dug are drier than normal, be sure to check before that first week is over. Containerized plants will dry out faster given the growing media used. The surrounding soil may be moist, yet the root system can easily be dry.
If we do not water and do not get any significant amount of rain, our perennials, trees and shrubs will go dormant early, just like crops do. Good fall color will be impacted as well and what color we get will not last as long.
Our existing lawns, even if not reseeded, should be watered with about one inch of water a week unless we get adequate rain. One inch of water should soak in about 6 to 8 inches. With our drier soils right now, even more may be needed depending on the soil type and the percentage of organic matter present. Our cool season grasses will grow vigorously this fall, filling in those spots where broadleaved weeds have been eliminated or where the annual crabgrass has been. Promoting a thicker lawn will prevent the return of crabgrass from seed next year.
Gardeners should not forget any perennial vegetables or small fruits either. That late season watering applies to them too. Rhubarb and small fruits have a significate amount of roots in that 6 to 8 inch soil profile. While asparagus crowns are farther down in the profile, they need to be moist as well. The word of the day is water.
Richard Hentschel is a Horticulture Extension Educator with University of Illinois Extension, serving DuPage, Kane and Kendall counties. Stay tuned to more garden and yard updates with "This Week in the Garden" on Facebook at facebook.com/extensiondkk/videos. The 2017 Kendall County Master Gardener Help Desk currently is open Monday, Wednesday and Friday from 9 a.m. to 12:30 p.m. at 630-553-5823 or at uiemg-kendall@illinois.edu.
About the author: Richard Hentschel’s expertise extends across several subject areas with specialties in lawn care, fruit tree production, woody ornamentals, and home and community gardening. During his 45-year career in horticulture and agriculture, Hentschel became a well-known and respected expert for commercial and homeowner audiences, industry organizations, and media. He retired from University of Illinois Extension in April 2022 with nearly 30 years of service as a Horticulture Specialist and Educator in northern Illinois.