What is crabgrass?

Crabgrass is a troublesome weed grass. It is an annual grass that germinates in the spring. The blades usually begin to appear mid to late June depending on the season and are a bright lime green colour. It looks similar to a miniature corn plant. As the plant matures they grow in coarse clumps low to the ground and spread out. A prime area to detect crabgrass is along driveway and sidewalk edges where it is hot and dry. Any areas of full sun would also be vulnerable to crabgrass. Crabgrass does not grow in shaded areas.

Why is crabgrass undesireble?

Crabgrass is an undesirable grass due to the weakness of the plant's structure, its coarse texture and unsightly colour. These characteristics do not blend well into a fine textured dark green healthy lawn. Crabgrass spreads very quickly and over time can start to choke out desirable grasses. Once the crabgrass dies in the fall you are then left with thin or bare patches which will need to be renovated. Once established, crabgrass can take several years to get under control.

How can I tell if I have crabgrass?

Quite often customers will confuse crabgrass with quackgrass which has some similar characteristics. This commonly happens in the early spring. A couple quick tips to determine if it is quackgrass or crabgrass are:

  • Are you seeing it all year round? If yes then most likely what you are seeing is quack grass. Crabgrass is an annual plant and the seeds germinate in the spring but the plants themselves are not visible until mid-late June. The crabgrass plants turn purple and die in the fall after dropping their seed heads
  • Is the grass you are seeing taller than the rest of the lawn? If yes then again what you are seeing is most likely quackgrass. Crabgrass is a low lying grass that spreads in clumps along the ground.

If you are uncertain if you have quack grass or crabgrass just call your local Weed Man Professional. They will provide a free healthy lawn analysis to determine which you have and the best treatment options

What can I do to prevent crabgrass?

Crabgrass favours sandy sunny locations in a weakened condition. Areas left thin due to insect damage and areas along sidewalks and driveways are prime targets for crabgrass attack. Customers often edge the sidewalk and driveway edges too severely and leave areas of soil exposed to the sun which allows the crabgrass seeds to germinate. Since the desirable turf grass has been removed there is no competition and crabgrass is allowed to thrive.

If you have any areas bare or thin due to insect damage or other problems you should top dress these areas in the fall. This will give the seed a chance to germinate and establish itself before the crabgrass seeds are able to germinate the following spring. The longer bare areas are left before they are repaired, the stronger the chance undesirable grasses such as crabgrass or quackgrass will be given a chance to invade.

A strong, healthy, properly fertilized, mowed and watered lawn provides the strongest defense against crabgrass. Thick, lush healthy lawns allow few open sites for crabgrass to establish. Remember crabgrass grows from seed every year in weakened stressed areas.

How can I treat crabgrass?

Crabgrass treatment combines reducing number of crabgrass plants with strengthening the lawn. Your local Weed Man Professional can advise you on the appropriate treatment for your individual lawn. Contact your local Weed Man Professional and receive a free healthy lawn analysis to determine firstly if you have crabgrass and then the best treatment plan for your lawn.