Controlling Annual Bluegrass When Overseeding Fescue in Fall

Annual bluegrass (Poa annua) germinates in late summer/fall as soil temps drop below 70°F. If you've had it before, you face a dilemma: pre-emergent herbicides stop bluegrass but also prevent fescue seeding. Here are two strategies.

Option 1: Benefin (Balan) + Delayed Seeding (Dr. Clint Waltz)

• Apply benefin at 2 lbs active ingredient/acre on Sept 1.
• Wait 6 weeks (mid- to late-October) to seed fescue.
• Downsides: Rate errors can extend the wait and inhibit fescue. Late-October seeding gives less establishment time before cold.

Dr. Waltz adds: if your fescue looked decent last spring, you may not need to overseed at all. A pre-emergent alone may suffice. Test by covering a representative area with a blanket/mat; if fescue rebounds thickly, skip seeding.

Option 2: Early September Seeding + Late Pre-emergent (Walter Reeves)

• Seed fescue on Sept 1 if weather permits. It may establish well before bluegrass germinates (avg. 70°F soil at 2″ depth occurs late Sept in Atlanta).
• Apply pre-emergent in mid-October.
• Check product label for specific seeding-to-application intervals.

Monitor Soil Temperature

Annual bluegrass germination begins below 70°F. Track local soil temps to time your operations.