What’s popping up in turf?
Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. Check the label of any pesticide referenced to ensure your use is included.
White clover and black medic
There are many weeds actively flowering in lawns right now. A couple that always catch my attention and are often found growing together are white clover and black medic. White clover is a unique weed in that some folks prefer to leave it in their lawns and has sometimes even been seeded in turfgrass mixtures for lawns. You might wonder why on earth anyone would want to seed white clover into their lawn when you may be thinking of how to get rid of it.
White clover is a nitrogen fixer, so the idea is that you could have clover and turfgrass co-exist in a lawn and the white clover would provide some nitrogen for the turfgrass. White clover’s ability to fix nitrogen makes this weed very competitive in lawns that are not fertilized or are growing on low fertility soils. One cultural recommendation to help turfgrass compete with both white clover and black medic is to fertilize. If you feel the need to kill either of these weeds before it takes over your entire lawn, products that contain the active ingredient triclopyr will be effective especially if you can hit them while they are flowering. If you can make it through the summer coexisting with these weeds in your lawn, your best time for treatment is in the fall when the weeds are storing carbohydrates in their roots for next year. Herbicide applications in the fall are more readily transported to the roots and effectively kill the weed once and for all.
Seedheads in lawns
Many lawns are really pumping out the seedheads right now. Some lawns had seedheads popping earlier in the spring, but many lawns have come on really strong with the seedheads in the last week. The cool temperatures and lack of moisture may have delayed the seedhead production in some lawns this spring. Seedhead production requires energy from the plant, so it is likely the turf will not only look stemmy due to the seed stalks, but the turfgrass may even thin out. Keep the blade sharp and provide some fertilization if you haven’t recently to help the turf recover. Also, the lawn is not going to be reseeded by seedhead production. Even if the seed was allowed to reach maturity, which would take about four months, allowed to dry and then harvested, you’d still need to make sure that seed would find a home in the soil in order to germinate. If you need to fill in some areas in your lawn, it’ll be easier to go buy some seed.
Following the very light rainfall earlier this week, it didn’t take long to find some young crabgrass popping through the soil. There are certainly plenty of voids in the turf right now for crabgrass to invade, so keep your eyes open. If you’re going to try and control it, doing it when it’s young is going to be easier than once it matures.