Regarding Richard's comment that Roundup will not work below 70 degrees. I'm sorry, but my experience over many years proves otherwise. 70 degrees on the southwest coast of Oregon doesn't happen but once in a blue moon, if then. I have used Roundup once or twice a year for years and it works very well, if slowly, even if used when the temps are in the 50s. As others have mentioned, it's important not to spray when there is potential for rain. When Roundup first came out, the requirement was for waiting six hours before rainfall. The labels now state two hours. Because of the lower temps here, I still hold to the six-hour rule as a precautionary measure (due to high humidity at times). Robin Hansen Southwest Oregon maybe 58 today...