Hey Wilsocn..... I'm in KY too. Have you applied your Scotts Halts yet? We moved last Spring, I did nothing then, no time. I'm just now getting ready to apply Scotts myself but this time I'm getting the one marked 'Super' on the bag.... has 6 parts more nitrogen. I wonder if this will make a difference, guess I'll see. I'm concerned, due to the mild winter here, I'm a little late but it will surely prevent some of the crabgrass.

Terps: I think that you may be crediting crabgrass with being a thinking creature, which it is not. Or you may be thinking that Pre-M "prevents" germination, which it does not - even though the name is "pre-emergent". Crabgrass seeds germinate when there is adequate moisture (think April showers) and proper soil temperatures. The Pre-M does not "delay" the germination, and the crabgrass seeds can't really "outlast" the Pre-M's effectiveness. The Pre-M works by preventing root formation after the grass has actually germinated. With no root system, it wilts and dies before you even see it. No second chances, no waiting for the Pre-M to lose it's effectiveness. It's germinated and dead. The only crabgrass that makes it is if the conditions for germination don't happen before the Pre-M barrier breaks down. If you want to bet that we might not get 60 degrees and wet weather before 90 days from now, than put down more at the beginning of Summer. I'm saving my money to use the additional Pre-M in very late Summer to prevent the Poa Annua germination period (which will overwinter and be NEXT Spring's headache).

But I'll respond. Please don't do what bvisailor did. If he/she had any long term success it was because the heavy rain washed all that top dressing away. Generally now is a poor time to put fescue, rye, or Kentucky bluegrass seed down. It also happens to be a poor time for bermuda, but for a different reason. So now is a bad time to seed. If you put bermuda down now nothing will happen until mid May when some of it starts to germinate. Then in June the rest of it will germinate. That's the only reason it takes 30 days is because most people SERIOUSLY jump the gun. If you are seeding with fescue, rye, or KBG now, you're also going to germinate all the crabgrass seed in the yard. Furthermore grass seeded now will not develop heat resistant roots by the time summer comes. The result is a crabgrass lawn by July. If you go ahead and seed now anyway, you don't need any topsoil. Grass seed sprouts at the surface. All it needs is continual moisture (just like crabgrass seed needs) for several weeks. The best time to do this is in the fall if you can stand to mow weeds until then. There are a few other tricks we can help you with. What do you want to do? If you want to do it now, we'll help you with the tricks and all the details. If you want to stretch through to the fall we will help you have the nicest weeds on the block until then ;-) Nicest weeds on the block is what I've had for the past 2 years. I'm patiently waiting for my grass to spread and take over the weeds.

The pre-emergents are a useful product, but they have their limitations. First, they have a window of opportunity. That might or might not be the 'useful life' listed on the label. That depends, obviously, on the conditions under which the product was put down. So let's assume you spray, and it's supposed to be good for three months. It might even stretch to four, but you can't count on it. Well, poa annua germinates in the fall. Those seeds become viable in the fall, winter over, and sprout in the spring. Crabgrass germinates in late spring, AND LATER. One would think that one could simply overdose the lawn, and spray every thirty days for twelve months, and that would do it. It might, by the way. I've been sorely tempted. But size of lawn, and expense, have kept me from it. Other than that, you've got the concept of re-seeding. The pre-emergents aren't a WEED (with a W) killer, they are a SEED (with an S) killer. The theory of a pre emergent is that 'no seed will germinate'. That's how you stop the cycle of poa, or crabgrass, continuing to grow from seeds from prior crops. But that means that grass seed won't germinate either, doesn't it? If your lawn is primarily Kentucky Bluegrass, that's less of a problem, as you can, with fertilization, get the existing plants to spread out, and fill in bare or thin spots. That's not possible with the ryes, and fescues. They don't spread much, if at all. Striking some sort of balance, between the need to re-seed, and putting down pre-emergent, is more art than science. Sometimes you get lucky. Sometimes you don't. But that really is the nub of the problem. But needing to put down multiple applications of pre emergent, over the course of a year, is fairly common. Having to do it for a two year or three year period, is fairly common. You've got to break that cycle of weeds-to-seeds-back-to-weeds-again. And it ain't easy.