It might be the lower temps or it might be that whitening seems less pronounced after Tenacity has been used a couple of times. It doesn't work any less effectively, just less whitening of surrounding turf. BTW, Tenacity is definitely affected by the rate of metabolism of the grass it is applied to.

Thanks Andy. I hadn't used since Oct., where I had more "immediate" (i.e. within a week) results. I was a bit surprised to see it go this long (and hang on), to give results. No complaints about Tenacity, but just checking to see if temp has to do with it. As you mentioned, metabolism does, which is based on temp typically. Appreciate the help Andy!!!