According to the Penn State College of Agricultural Sciences, crabgrass begins as seeds. These seeds germinate in spring or early summer. While crabgrass dies after the first hard frost in fall, crabgrass seeds remain dormant in winter, and the seeds then grow again in the following spring when ground temperature warms up. Without action to prevent crabgrass seeds from germinating, homeowners will likely end up with patches of crabgrass throughout their lawns every summer. The healthier a lawn is, the harder it is for unwanted grasses like crabgrass to thrive. The following are a handful of strategies that can promote a healthy lawn and make it more difficult for unsightly crabgrass to establish itself in the months ahead.

• Keep grass at a consistent length, and don›t cut too low. Maintaining a consistent length of grass by mowing at regular intervals can make it hard for crabgrass to thrive. Crabgrass requires ample sunlight to germinate, so grass that is not cut too short may keep crabgrass from growing in. Of course, grass should not be allowed to grow knee-length, either. By raising blades to the mowing height appropriate for their type of grass, and mowing at regular intervals so the grass remains at that height through the summer, homeowners can promote healthy lawns and make it harder for crabgrass to germinate.

• Never cut too much of the blade off of the grass. When mowing, don›t cut too much of the blade off the grass with each cut, even if the grass seems especially long. As noted, cutting too low allows sunlight to reach crabgrass seeds. But cutting too much off the blade, even if the grass is still high after a mow, can injure the grass. Injured grass can make lawns more vulnerable to weeds and crabgrass.

• Apply a pre-emergence herbicide. Pre-emergence herbicides kill germinating grass seedlings before they emerge from the soil. Follow the manufacturer›s instructions regarding when and how much herbicide to apply. If crabgrass has already started to grow, it›s likely too late to apply a preemergence herbicide.

Crabgrass is an unwelcome invader in many lawns. Spring can be a great time to prevent this unwanted guest from returning this summer.