As part of your lawn care schedule, you may need to take steps to control crabgrass in your yard. It can take several years to manage the problem since seeds can stay dormant for several years before germination, so the best time to start the battle is now.
Begin With Hand Removal
If you only see a few crabgrass plants, you can try to remove each one by hand. Aim to do this before the seed heads form and make the problem worse. Larger crabgrass populations may need a chemical control.
Use a Pre-Emergent Herbicide
One of the best ways to control crabgrass is to use a pre-emergent herbicide twice in the growing season. These compounds are able to kill any seeds that have recently sprouted , so the crabgrass never gets a chance to take hold. This is important because each plant produces thousands of seeds
Begin with a round in spring to catch as many of the seeds as possible. Follow up with another session right before summer to catch any that have started growing since the last treatment.
If you find some persistent plants that have still managed to grow, you can use a post-emergent herbicide that specifically mentions crabgrass on the label. Some herbicides affect all grassy plants, so your lawn grass can be affected as well. You want to especially avoid compounds like glyphosate (Roundup) since they are designed to kill any kind of plant present.
A word of warning: Do NOT use a pre-emergent herbicide at the same time that you plant grass seeds. Since it is tied to germination, your desired lawn will not sprout either. Plan these events to be several months apart so the grass will grow, but you still stop the crabgrass as much as possible.
Keep Your Lawn Happy and Healthy
If your lawn is lush and growing well, it is less likely that crabgrass will be able to compete and become established. Make sure you are doing your yearly maintenance tasks like aeration, fertilization and any reseeding needed.
Image by Matt Lavin under a Flickr Creative Commons Attribution-ShareAlike License