Answer: Crabgrass is an annual weed and it begins germinating very early in the season; the good news is it dies every winter. You are right that you can't use the pre-emergent and seed at the same time. It is always a race to get the desired grass to germinate before the crabgrass. Most often, spring seeding fails for this reason but you can certainly try. The best time to seed is actually about the end of August to beginning of Spetember. Another option might be to use sod if you have big areas. If you have a truly large area that needs to be redone, you may find the following lawn renovation information helpful.
Good luck with your lawn this summer!
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