September Turf Tips

Jeffrey Derr and Adam Nichols

As our temperatures decrease as we move into fall, there are several items to consider for lawn maintenance. Winter weed control, fertilization in cool-season lawns, overseeding of both warm and cool-season lawns, and fall fungicide applications of warm-season lawns are topics to consider this time of year. Listed below is a brief summary. To read the complete article, click here .

Once temperatures cool in September, coupled with rainfall to trigger germination, winter annual weeds will start to emerge. One weed of concern is annual bluegrass, often called poa due to its scientific name Poa annua. F One way to address control of annual bluegrass would be to apply a crabgrass preventer prior to annual bluegrass germination. In most cases, though, one would not be able to overseed the lawn.

Another advantage of applying a crabgrass preventer in late summer or early fall is that they will also control certain winter annual broadleaf weeds like common chickweed and henbit. One winter annual broadleaf weed that has increased in the area is lawn burweed (Soliva sessilis), a weed that produces sharp spines.

Fall is the best time to establish and strengthen cool-season lawns. Starting in mid-September through early November, tall fescue, Kentucky bluegrass, and fine fescue can be seeded or overseeded. At the time of seeding, these cool-season turf species can be treated with products containing mesotrione for weed control.

When overseeding a bermudagrass lawn for winter color, perennial ryegrass ais the recommended species. Neither preemergence products nor mesotrione should be used at the time of overseeding bermudagrass lawns.

Fall is the time to fertilize cool-season turf such as tall fescue. Fall is not the time to fertilize warm-season grasses like bermudagrass, zoysia, and St. Augustine.

When maintaining a warm-season lawn, fall is the best time to apply needed fungicides to prevent and cure the worst diseases that affect these turf species.