http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7456.html

UC Davis has great info even if you're not in CA... most of the info
applies.

Nicole
"Chas Hurst" wrote in message
...
The crab grass slipped in on my lawn this spring. I have sprayed Ortho
crab grass killer on it with very dissapointing results. It was left over
from last year. Does it have a shelf life once opened? Are there other
brands of crab grass killer that work better?

Chas Hurst