Using old herbicide


LawnSite Member
I wanted to see if anyone has had any experience using old herbicide that hasn't been properly stored according to the label.

I have a bottle of Q4 that was left in my enclosed trailer all last winter and this summer. Not exactly a "cool dry place". I mixed and sprayed some on my lawn yesterday but its too soon to be sure if it's safe to use on a customers lawn just yet. Figured I'd ask here if I should just buy some more or use what remaining product I have left.

That Guy Gary

LawnSite Gold Member
SW Idaho
Most of the stuff I use at home is out in the garage. I keep it heated enough to stay above freezing because the washer and dryer are in there but it gets pretty nasty in the summer with 100+ degree days, never had anything go bad.


LawnSite Member
To be honest should be fine. Wait for results from your lawn to be sure.
It's been about 2-3 days and it's already smoked oxalis and plantain that I sprayed. Ground ivy and crabgrass is starting to die but slowly. Desirable turf seems fine so far.