Originally Posted by ArTurf
This is an area that is approx 25% St Aug. You don't think the Prodiamine will inhibit spreading? I thought you didn't use this particular pre.
Prodiamine is what I use on the fescue in TN. I use "Gallery" on the warm-season turf on the coast. In TN, an application of Stonewall or Dimension is put down between Feb. 15-Mar.15 with a follow up in May. By Sept grass could be dormant but if it is a normal season another application to take through fall season.
Putting down "Gallery" now or before Greenup takes us till May, then another in August since the heavy irrigation on the sand washes a lot of it out. You've basically got to just watch you IPM and adjust your products and times. So far--knock on wood--my lawns are weed free. Very little of anything until weed pressure forces us to spray for sedges or Kyliinga.
To limit the root prunning on the St. Augustine, apply a light application now. The stolon growth has not started yet, when it does the hair roots that root it into the ground will tell you when to put down another application. Watch the growth from the crown outward. Generally not until after June on the coast but you may be different. I would refrain from using any pre-em during the active regrowing time. Sometimes it year round as in Florida but it does slow at times. If things are very bad on the Crabgrass, look into "Prograss" and read the label.