Laura,

I have not used this product, but have included a link that might be helpful. From what I can gather it should be used primarily in spring when "grass weeds are young, exposed and actively growing". I would guess that by the time seed heads are forming the plants would not actively take up enough chemical to be very effective. Does the label itself say that this product can be used in summer or did you read that somewhere else?

I'm also at a loss for the recommendation of not using on "tillered" growth. The Bermuda in my garden starts suckering awfully early in the year. Perhaps the chemical kills only the top growth allowing any existing rhizomes buried in the soil to resprout?

Mike

Here is a link that might be useful: Fusilade