I find those little sprigs beginning to show in June (once the weather gets
hot) so it must take a certain temp to really get those seeds going. The
seedlings are very tender and come out with little effort. Of course, finding
them under what's already growing is the real chore since it will sprout in
total shade. It also sprouts in sunny spots.

Persistance is a virtue when come to getting this pest out.

Marcy