I don't think it's too late.. IMO the more you can do to knock down the CG the better. My yard is getting "Max'ed" in a couple of weeks.

Crabgrass is an annual and it will die with the first hard frost anyway, so let that guide your decision. If you're not going to overseed in the heavily infested areas, I don't see the point in killing something that will die in six weeks on its own.

You're right in asking if preemergent next spring is the solution to your problem. Yes, it is.

That said, there are other uses for weed killer in the fall. September and October are the best times to control winter weeds (annual weeds that germinate in the fall and flower in the spring, e.g. henbit) and perennial broadleaf weeds like dandelions.

Do you want know when it will *actually* rain? The morning after I spray Weed-B-Gon is when! Sprayed the lawn last night and of course it rains this morning. This stuff is supposed to "rainfast" an hour after application. Let's see. I have the worst luck.

I hope you folks aren't using WBG Max to kill crabgrass. There is a separate product "WBG Max Plus Crabgrass Control". It contains Quinclorac for crabgrass control. The standard WBG Max product does not, and will not control crabgrass.

Yes, mine had the CG control.

What makes these chemicals rainfast isn't any special ability to repel water. It's the fact that the plant takes in the chemicals through the foliage and transports it to the roots where it does its damage.That can happen real fast. It was probably "rainfast" less than an hour after you applied it, and it certainly wasn't hurt by rainfall the following morning.