How to Get Rid of Crabgrass
Throughout North America, homeowners confront an annual scourge that can turn a lush, smooth emerald carpet into a weedy mess: crabgrass. Specifically, large crabgrass (Digitaria sanguinalis) — which also goes by the name hairy crabgrass — and smooth crabgrass (Digitaria ischaemum) can invade lawns, flower beds and vegetable gardens, rapidly becoming a nuisance. When one plant can produce an estimated 150,000 new crabgrass seeds, you know it’s going to have an easy time taking over a customer’s yard!
What is Crabgrass and Why Not Just Let it Grow?
Crabgrass and other unwanted weeds steal valuable moisture and nutrients, taking them away from more desirable plants, including lawn grasses, flowers and vegetables. Just as important is that crabgrass is ugly and makes a lawn look unkempt. Crabgrass is an annual grass that grows from seed, and when the plants die in the fall they leave gaping holes in a lawn.
To manage crabgrass, knowing how to ID it is important. After that, your customers can use several methods to control it. Biological control of crabgrass is easy, but there are also several crabgrass control products available to your customers.
What Does Crabgrass Look Like
A traditional lawn is a green carpet is actually composed of individual blades of various grass species. Lawns throughout North America are sown with cool season grass, warm season grass or a mixture of both types. The type of grass grown from one yard to the next may differ significantly. Crabgrass, however, stands apart from these other grasses.
Identify crabgrass by looking for:
- Clumps or clusters of grass that look different from the surrounding grass areas.
- Bare patches of soil. Areas that sprout new grass without seeding may harbor crabgrass.
Large crabgrass (aka hairy crabgrass) has:
- Seedlings with light-green leaves that are hairy on the upper surface.
- Leaves on mature plants that are about three inches long and hairy.
- Branches that are two to five inches long.
On the other hand, smooth crabgrass:
- Grows to a mature height of six inches.
- Sets seed when it’s cut way back — even down to one-quarter of an inch tall, smooth crabgrass can still produce seeds.
- Has seedling leaves that are light green and smooth.
- Has leaf blades that are pointy.
- Forms branches on its stems, with the branches about 1/2 inch to 2 1/2 inches long.
Of the two types, smooth crabgrass is a lot more common in lawns because it can survive repeated close mowing. Large crabgrass doesn’t like a close shave, so it doesn’t thrive as well in groomed areas such as lawns, but it grows more easily in open pastures and fields.
How to Get Rid of Crabgrass Naturally
There are several steps your customers can take to fight crabgrass plants and seeds.
- Let the grass grow a little taller: Crabgrass loves full sunlight. When a lawn is cut very short, the blades of desirable grass can’t shade the rest of the lawn. Crabgrass can seed in those sunny areas. Various grass species should be mowed at different heights, so point customers to the local Cooperative Extension office for the best species and the height at which they should be mowed. For lawns that contain a blend of grasses, homeowners should err on the side of caution and let it grow a little taller.
- Choose grass species suitable for the climate: The healthier the overall lawn, the less room there is for crabgrass to grow. Species suitable for your climate will have an easier time setting down roots and growing into a healthy, vigorous lawn.
- Fertilize regularly for the grass type: Fertilizer encourages growth, and a flush of new lawn growth will crowd out crabgrass seedlings.
- Water less frequently but more deeply: One common mistake homeowners make is to water their lawns lightly and frequently. A deep watering every few days is actually better for grass and discourages crabgrass. Allowing the lawn to dry out between watering encourages grass to put down deeper roots. Light watering results in shallow surface roots that can dry out easily.
Controlling Crabgrass in Garden Areas
Crabgrass that invades flowerbeds or vegetable gardens should also be controlled through simple horticultural practices. Pulling crabgrass by hand is the preferred, albeit tiring, method. You can also hoe the area around the plants to pull up crabgrass by the roots. Mulching your garden with wood chips or hay reduces weeds and increases natural moisture retention near the roots of plants, a plus for drought-prone areas.
Crabgrass Prevention From Safer® Brand
Crabgrass preventers are good at stopping crabgrass seeds from germinating. Since each crabgrass plant produces a huge volume of seeds — and even small plants can begin producing seeds when relatively young — preventing seeds from germinating in the soil is a useful crabgrass prevention tip.
Concern® Weed Prevention Plus® is an excellent crabgrass preventative made from corn gluten meal. Weed Prevention Plus® kills the roots of sprouting seeds, so it nips germinating crabgrass as it emerges, yet it won’t harm established lawns and gardens. As long as existing flowers and vegetables have several sets of leaves, your customers can use Concern® Weed Prevention Plus® near their plants.
As previously mentioned, a healthy lawn prevents crabgrass from gaining a foothold. Keep a lawn healthy with Ringer® Lawn Restore® II Fertilizer. After all, underneath that lovely lawn is a thriving ecosystem of fungi, bacteria, insects and other living creatures that contribute to healthy soil and grass. Ringer® Lawn Restore® II Fertilizer supports and restores this healthy ecosystem so grass can thrive. It provides the micronutrients lawn grass craves through a balanced, economical formula.
If all else fails try Safer® Brand Fast Acting Weed and Grass Killer to spot-treat existing crabgrass. This weed killer features a simple pump spray bottle to kill individual crabgrass plants. It’s fast acting, and the lawn can be reseeded with grass seed blend in as little as two days after application. A larger size concentrate is also available.