Seedheads in lawns are a natural process that can’t be avoided, but keeping your mower blade sharp and applying fertilizer will help the lawn be healthy and good looking, according to Kevin Frank, Michigan State University Extension, Department of Crop and Soil Sciences
Turfgrass producing seedheads is an annual rite of spring. The cool spring temperatures have delayed seedhead production. The common lawn grasses, Kentucky bluegrass, perennial ryegrass and tall fescue all produce seedheads, as do some grassy weeds like annual bluegrass (Poa annua).
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. Consider a fertilizer application following the seedhead flush to help the turf recover, especially if you haven’t fertilized yet this spring.
Keep the mower blade sharp and don’t lower the mowing height to try and remove seedheads. Annual bluegrass produces seedheads below the 1/8-inch mowing height on golf course putting greens, so lowering the mowing height is not recommended.
For those that think the lawn is going to be reseeded by the natural seedhead production, think again. Even if the seed was allowed to reach maturity – which would take about four months, time 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.
Source: Kevin Frank, Michigan State University Extension, Department of Crop and Soil Sciences