Pendimethalin photo degrades quickly by comparison, it has a yellow dye impregnated on it to slow the process(UV inhibitor) until it comes in contact with moisture and soil.It can also be a root pruner and moves to some degree in the soil.The Ag sector know this product as Prowl and it is very old chemistry.Dimension is very much different in that it stays put and can be applied somewhat later than Pendi as it has some degree of reachback or post control on 1-3 tiller stage crabgrass.The midwest turf market leans towards Barricade and Dimension but they cost more than Pendi.In Ohio the heat thins out our desirable turf and sets the stage for crab grass germination and then the first week of October or a 35F night will kill it all out. Different situation than yours.
