Annual Bluegrass Blues
A friend of mine who is an avid golfer actually knew this weed’s scientific name. “Oh, that’s Poa annua. I hate it.” When a guy who’d rather golf than garden can ID a weed like a botanist, that’s evidence that it’s a bad kind of weed.
Annual bluegrass is able to grow in any little crack or crevice, and it thinks it’s gone to weed heaven when it gets free reign over a home lawn like the one in the photo.
This is a cool-season weed. That means that it germinates in the fall, grows a bit before winter, then really takes off when the warm days of late February and March roll in. By April it’s in full bloom like a million little pampasgrass plants, and ripe seeds are only days behind.
Your only means of addressing this weed will be by preventing it. There is no control once it gets started. Since it germinates in early fall, you must apply a pre-emergent herbicide such as Dimension, Team or Halts between August 25 and September 7. If you miss that timing, you’ve blown it for another entire year.
At this point in the growing season, just keep it mowed as best you can. Your permanent lawngrass will soon be growing vigorously, and the annual bluegrass will quickly fade into history.
But if you have seeds like you see in Facebook friend Dianah Zehetner’s photo, this baby is going to be back at full speed, so mark the calendar for September 1. You have a date with Poa annua destiny!