1. Pull the crabgrass up—roots and all. ...
2. Seed the lawn to fill bare areas. ...
3. Deeply water your lawn one or two times per week.
4. When mowing, keep the grass at about three inches tall. ...
5. Next spring, apply a pre-emergent around the time your flowers and trees bloom.
6. How to Kill Crabgrass. If you only have a few crabgrass plants in your lawn, you can treat them with a ready-to-use product like Scotts® Spot Weed Control - For Lawns. This spray kills listed weeds, including crabgrass, down to the root without harming your lawn, when used as directed.
7. The best weapon you have to know how to kill crabgrass is pre-emergence herbicide (also called crabgrass preventer). You apply this product in the spring before the crabgrass seed sprouts. This granular herbicide works by creating a chemical barrier at the surface of the soil.
8. Post Emergent Crabgrass Control
9. Crabgrass is a pain for many gardeners and homeowners. This weed is a type of broadleaf weed, also known as crowfoot, water grass, or summer grass, is one of the most common weeds in home lawns. Crabgrass can be difficult to control, but DoMyOwn has you covered with a wide selection of professional grade products you can use to do your own lawn care.
10. Syngenta Tenacity Turf Herbicide

Syngenta Tenacity Turf HerbicideThis is the very best, most-effective crabgrass killer and preventer. Working as such, it won't kill grass in your lawn, so you can apply it in before spring to prevent grass weeds from germinating, or even afterward and in the summer to kill full-grown weeds.