Poa Annua (Annual Bluegrass) in Your Lawn?

Poa Annua (Annual Bluegrass) is very obvious in dormant Bermudagrass and Zoysia lawns right now.  The best approach is to prevent this weed from germinating in early fall.  Circle Late August/early September on your calendar as the time to put down a preventer to keep Poa Annua from growing in your lawn next year.  Don’t be tempted to spray weeds in dormant lawns with Roundup as you may damage your good grass even though it is dormant.

This is an early spring picture of Poa Annua in a Bermudagrass lawn. Notice the light colored seeds. (Click photo to enlarge)

Lawn weeds like Poa Annua (Annual Bluegrass), Common Chickweed, and Henbit are “winter annuals”.   This means they germinate in fall, thrive in spring and then die during summer, but not before scattering seed so the cycle can start all over again in fall.  (“summer annuals”, like Crabgrass, Foxtail and Barnyardgrass, have the opposite cycle of germinating in spring, thriving in summer and dying just prior to winter, but not before scattering seed so the cycle can start all over again in spring.)

So if you vow now that you want to stop these winter annual weeds from invading your lawn, you need to pick up a bag Scotts Halts or Scotts Turf Builder with Halts so you can treat your lawn around Labor Day.  (You apply these products in early spring to prevent crabgrass and other summer annuals.  Apply the same product in early fall to prevent Poa Annua and other winter annuals.)