While difficult to prevent completely, there are some steps you can take to discourage crabgrass from growing in your lawn. This includes maintaining dense, healthy grass that doesn’t give crabgrass the opportunity to establish itself. You can do this by:
Mowing at the proper height for your grass, not too short (ideally setting your blade height to 3 ½ to 4 ½ inches).
Fertilizing your lawn regularly to prevent bare patches.
Watering your lawn deeply to encourage stronger grass root growth.
Seeding bare spots and tending the grass until it’s mature.
Pulling the crabgrass by hand, ideally when the soil is moist to make the job easier.