Soil temp, not air temp. So this is the first day? Is anything greening up? Has it rained recently? Because all grass seed needs fairly consistent soil surface moisture to germinate. If you can allow the soil surface to dry out completely before you water (and I'm talking about several weeks at that low temperature), then you should not have crabgrass issues. Is your turf fairly dense? Dense turf will almost always stop crabgrass because crabgrass seedlings need plenty of sunlight. If the grass is tall and dense, then any seedlings which sprout will not get enough sunlight to survive. If you have moist soil and thin turf, I would put the Halts down now.

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.

Part of the problem with crabgrass in bermuda is they both love the same conditions. The advantage you have is in withholding moisture, especially in the spring. The crabgrass will die at first frost. The bermuda will slow down and go dormant about the same time. No advantage yet. Whatever you do, do not over seed with rye grass to keep your lawn green over the winter. There are several reasons for this, but one is so you can get the earliest green up of the bermuda possible. You want every sun ray to hit the grass and bring it out of dormancy. Over the winter you should be watering once per month. When the temps rise into the 70s, you can move to once every 3 weeks. Temps in the 80s you can go to once every 2 weeks. Above ninety and go to weekly watering. Crabgrass needs continual moisture to germinate. If you withhold moisture, the soil will be dry most of the time and the crabgrass seed will not germinate. If you have a very dense turf, the crabgrass will not move in.

Dear Jill Catt Thank you very much for your inquiry. Plants should be no issue for the crabgrass herbicide. Was there fertilizer associated with the application or just straight herbicide? Again, thanks for the question and let me know if you have more. Respectfully Trey Rogers, The Briggs & Stratton Yard Doctor, YardDoctor.com