Laurie, you'll have to mow fairly often IF you get a good stand of rye over your grass. Rather than do that, why not put down a good pre-emergent? This will absolutely stop the cool weather weeds in your lawn. You put it out with a fertilizer spreader. There are alot of different brands. Look for one that says "crabgrass preventer" or that controls things like henbit. They will control way more than that. I use them in my flowerbeds too if I don't care about having volunteer flowers. It's time to be putting it out now, as it stops the seeds from germinating but doesn't kill them once they do.

Depending on the size of your lawn a thin topdressing of compost or manure in the spring will work absolute miracles on your grass.

I will try the compost in spring. I also heard just used coffee grounds works too. I don't use herbicides or pesticides, except Amdro bait when needed for a bad fire ant situation.
laurie

Laurie, I prefer perennial rye over annual, because it doesn't grow as fast which means you don't have to mow as often. Costs almost twice as much, but to me it's worth it. Both will die when late spring heat sets in.

I have used fescue to overseed an area that is mostly St Augustine. I have done this for years to help the St Augustine fill in and prevent erosion in the winter. This has helped alot so I highly recommend it. I also use perenial rye on higher traffic areas (dogs running) & it's worth it.Both fescue and perenial rye will stick around a long time and not die out completely where I am (Jackson). Hope this helps.