Dallisgrass is one of the most troublesome weeds in the Southern U.S., and it is occasionally found farther north. It forms distinct clumps in mowed lawns and produces tall, unsightly seed stalks. Although hand-pulling and selective herbicides are not effective in controlling Dallisgrass, it can be killed.
Dallisgrass: a Perennial Problem Dallisgrass is a deep-rooted bunchgrass that spreads by both seed and underground rhizomes. It prefers warm, moist areas and begins growth in early spring, readily invading bermudagrass and other warm-season lawns. Although difficult to control, Dallisgrass is usually less of a problem in lawns mowed frequently at a low height.
Dallisgrass forms distinctive star-like clumps of 2- to 6-inch stems and coarse 4- to 10-inch-long leaves. The seed stalks grow from the top of the stems between May and October and have three to five fingerlike segments covered by fine, silken hairs. Dallisgrass grows most vigorously in warm summer weather, but remains green in winter.
Pulling Won't Get It All Hand-pulling Dallisgrass doesn't provide effective control, because some of the rhizomes will be left in the soil to grow back. Selective herbicides will not control Dallisgrass, but you can spot-treat actively growing weeds with Roundup® Ready-To-Use Weed & Grass Killer III. Because Roundup® Ready-To-Use Weed & Grass Killer III will also kill desirable lawn grasses that are contacted by the spray, wait three days and repair treated spots by reseeding or plugging as necessary.