"Red" wrote in message
...
I'm fighting a bad poa annua problem. The best advice I've found is
preemergence application in late summer-early fall. Since this crappy
weed/grass germinates in the fall but doesn't show growth until late
winter/early spring, I'm confused about when to apply the
preemergence. The instructions are generic and I'm sure different
zones would have different application 'dates'. The instructions also
state it needs 1/2" water within 14 days of application to activate
the product. When activated, how long will the product remain
active? In other words, I've seen the poa annua produce green sprouts
over a 2-3 month period, so would one application of preemergence
remain active long enough to cover that long a period?

Come on, Eggs, and jump in here.

Red

Hello Red, you didn't say where you live or which pre-e you're using but
fwiw I
put down some dimension this week for just that purpose. I'm in north
central
Ohio. You have to be careful to not root prune your desirable turf if it's
at all
stressed, it's also nasty on bentgrass

Oh and forget about seeding this fall in the treated areas.