Poa annua is as common a lawn weed as they come. It looks a little like Kentucky bluegrass, except it has a lighter shade of green, shallower roots, and less drought resistance. It dies off when the weather gets hot, leaving big empty patches in your lawn. Keep it out by spreading a crabgrass preventer in late summer, before seeds can sprout in the fall.
Poa annua loves damp, shady areas. Fight the weed by watering deeply and infrequently. Its shallow roots can't reach down to where the moisture is.
Poa annua is short. When you mow your grass at 3 inches, you make it hard for poa to survive. Lawns with taller grass have very few poa problems.
The poa seed heads that were dropped in the spring are waiting for fall to sprout. You can stop them by spreading a pre-emergent in August or early September. That will stop seeds from sprouting.
If poa has taken over your yard, you may need a fresh start. Treat your lawn with Round Up® Weed and Grass Killer in the spring or fall. Then reseed with quality grass seed, such as Scotts® Turf Builder® Grass Seed after 7 days.
Poa Annua, or Annual Bluegrass, is an annual weed that looks similar to a regular lawn grass for a short while. It has shallow roots, and develops a short seed head early in the season. By the time summer heat hits, the weed goes dormant, leaving big brown areas in the lawn.
