An aggressive lawn invader

Published 12:00 am Sunday, March 17, 2019

With all the rain and warmer temperatures many have beautiful, green lawns.

Unfortunately, there is a weedy grass that seems to be invading our fescue lawns. The grass is rather aggressive, low growing, bunch-type grass that has an abundance of white seed heads.

That weedy grass is annual bluegrass or Poa annua. It is a common grassy annual weed that germinates in the fall and is not noticeable, only to become aggressive in the spring. The winter annual dies in early summer as the temperatures rise steadily above 75 degrees.

Annual bluegrass becomes a problem in fescue lawns because of
• mowing too closely,
• shallow, frequent irrigation,
• poor soil drainage,
• improperly timed fertilization,
• soil compaction from pathways or heavy equipment,
• and too much shade.

Most people want to know what can be done to eliminate the weed from their fescue lawns. Unfortunately, there is no easy control for this winter weed. Homeowners must use a pre-emergence herbicide in early fall before temperatures begin to cool.

Unfortunately, this is the time to seed lawns with cool season fescue. Some preemergence herbicides prevent fescue seed germination.

Eliminating unfavorable growing conditions and careful preemergence weed control applications in the fall is the best method to control it.

Go to for more detailed information about annual bluegrass.