Now that we have gotten a lot of rain, plants are responding and that has been driving questions to Master Gardener Help Desks in all the counties I get to work in.
Q: My lawn finally has begun to green up after the drought, what should I be doing to get it back in shape?
A: It normally takes about two weeks for a lawn to start to green up after weeks of dormancy. Spots that are not coming around can use a little help. Rake out the browned dead grass, add some top dress material like screened black dirt or a compost to bring the soil level up again, and then re-seed. We are nearing the end of the ideal window for getting seed in for the fall season, so do it soon. Sod can be put down into October. Begin to mow more regularly and consider a fertilization now that the lawn can benefit from it. Core aeration is another project that benefits the lawn. The softened soil will allow the core aeration machine to penetrate into the soil easily. Coring helps break down thatch, allows more water and air into the soil profile and breaks up soil compaction.
Q: In the drought, foliage on my trees lost their luster. Will that come back before the leaves fall?
A: Even though we now have rain, those leaves will not turn around. However, the rain certainly will help the overall health of trees, shrubs, groundcovers and evergreens and get them ready for our wintery weather. Foliage over the next few weeks will be preparing for cooler night temperatures and warm days to give us some autumn color. Unfortunately, the color show may not be as brilliant as past falls’ because of the summer drought that left portions of the leaves permanently damaged.
Q: While my lawn was dormant, crabgrass was not. I have patches where crabgrass has taken over. What do I do?
A: Crabgrass is a warm-season annual and has the ability to sprout all summer if conditions are right. Most of that crabgrass germinated earlier (back in the late spring) and without competition from our lawns this summer, crabgrass took advantage of thinning turf and any open areas in the lawn. The crabgrass will die at our first good killing frost, but then it is too late to re-seed those areas. If the crabgrass took over an open area, removal and re-seeding is an option if done right now. Sodding also is an option. If the spots are less than about 4 inches in diameter in the lawn, next season the existing grass should be able to catch up and fill in those spots. Either way, plan on some crabgrass preventer next spring for sure, as the crabgrass has certainly created a large seedbank for 2019. For more on crabgrass and lawns, visit https://go.illinois.edu/ManageCrabgrass.
• Richard Hentschel is a horticulture educator with University of Illinois Extension, serving DuPage, Kane and Kendall counties. The Kendall County Master Gardener Help Desk is open from 9 a.m. to 12:30 p.m. Monday through Friday at 630-553-5823.