baby crabgrass

How to Prevent and Kill Crabgrass – Top Best Crabgrass Killer 2021

A lush green lawn is the pride of any homeowner. Not only is it inviting for outdoor living, it can actually add to the value of your home. But a flawless lawn is work, and there are enemies that must be battled. The number one weed problem for lawns is a crop of crabgrass. These pesky lawn weeds emerge quickly as the days grow longer in late winter and early spring. As the soil warms, conditions are prime for germination of the tiny, profuse seeds. And once germination takes place, the growth of this unwanted brand of grass is extremely quick. This gives it a head start over both cool and warm season grass varieties especially attacking cool weather grasses like fescues, ryegrasses, and bluegrasses. Even if a lawn has been well-maintained against crabgrass in previous years, seeds are likely to be lurking in the soil just waiting to invade bare, weak spots in the lawn.

Identifying Crabgrass

baby crabgrass
Crabgrass early sprouting as resembling young corn plants

Identifying Crabgrass from other grass varieties is not all that difficult. The bigger problem is identifying it before it gets too late for early treatment. Early treatment is important because crabgrass grows in length before beginning the typical star-shaped pattern that makes it easier to recognize. It may blend in with other grass. As crabgrass matures, it forms mats that grow rapidly, much faster than its more desirable relatives, choking and eventually killing it.

The avid gardener can recognize early sprouting crabgrass as resembling young corn plants. For others, it may be helpful to find an online image of a corn plant. The blades are about a quarter-inch wide. Lawn grass and most other weeds that tend to plague lawns will have a thinner blade.

As crabgrass matures, it will be easier to identify. You may see only one with the familiar star-shaped pattern, or several together forming a dense mat ready to smother out competing grass and other weeds.

After crabgrass reaches its final stage in the fall, purplish streaks appear as the weather cools down. There will be plenty of runners at this stage, ready to populate the next spring’s lawn by scattering seeds that will lie dormant until then.

Bermuda grass also shoots out runners called stolons, but not as far out as crabgrass. Bermuda grass stems are also thicker and the leaves are wider. Saint Augustine grass also produces runners, but they are longer than the one or two-feet-long crabgrass runners. St. Augustine blades are also wider.

aged crabgrass
Crabgrass reaches its final stage in the fall.

Common Methods to Prevent Crabgrass

Crabgrass infestations can occur in some lawns and stop at the property line of another lawn. And there can be instances where infestation has taken place even when a crabgrass pre-emergent has been used. This is due to poor lawn or soil care. Thin or bare areas in lawns are an open invitation for crabgrass infestation. Crabgrass flourishes in sunlight and moist soil.

1. When to Begin Watering Your Lawn

Many homeowners don’t water their lawns until it is needed in late spring or early summer. Their lawn looks dry and they give it a good soaking. This is about the same time any crabgrass seeds will want to sprout. In dried out soil, grass blades are thinner. It will take the grass longer to recuperate and begin growing again. Meanwhile, crabgrass is ready to thrive, soaking up the water and sprouting before the grass can thicken up. It will be hard for the revived grass to compete with crabgrass at this stage.

2. Seeding for a Thicker Lawn

Seeding early and late produces a thicker lawn. This helps keep crabgrass out by preventing the bare areas it loves. Seeding early helps get the lawn growing, at least, a few weeks before the soil is warm enough for crabgrass to sprout. Seeding late, after the crabgrass dies out in the fall gives plenty of time to seed any thin areas in the lawn.

Crabgrass doesn’t tolerate shade well. A thicker, taller lawn keeps the soil cooler by preventing sunlight from reaching it. Mowing too short will allow the sun to warm up faster than it should. Short mowing weakens the lawn and makes it easier for crabgrass to grow. Avoid scalping along walkways, driveways, flower beds, or the lawn edges.

3. Improving Your Soil to Prevent Crabgrass

Improving the soil can also help deter crabgrass. It loves clay and compacted soil. It tolerates salt and other toxins. Using organic fertilizers and other amendments like composting changes the soil structure. Treating the lawn soil helps aerate, detoxify, and relieve compaction making crabgrass infestation less likely.

Best Crabgrass Killers 2021

Hindsight is 20-20 in most cases, and preventing crabgrass is no exception. Fortunately, when crabgrass infestation hasn’t been prevented naturally, several good commercial crabgrass killers are available. When used as directed, none of them will kill most grass varieties.

1. Compare-N-Save Concentrate Grass and Weed Killer

This product claims visible results in as little as two to four days. It is rainproof in two hours. The concentrate contains 41-percent of the active ingredient glyphosate. It makes 85 gallons of ready-to-use spray and covers over 25,000 square feet. However, glyphosate only works on actively growing weeds, and is ineffective on seeds and dormant plants. It doesn’t give the same results as a pre-emergent herbicide.

2. Spectracide 95702 Weed Stop for Lawns Plus Crabgrass Killer Concentrate

This product is available in a one-pack of 32 ounces. It not only kills crabgrass but is also effective on over 250 other weeds such as yellow nutsedge. Used in a tank sprayer, results and be seen in a few hours. It may be worrisome to some as it is restricted in at least two states including Hawaii and New York. However, it contains some of the same ingredients used on PGA golf courses and award-winning lawns.

3. Bayer Advanced 704140 All-in-One Lawn Weed and Crabgrass Killer Concentrate

This product kills crabgrass and other lawn weeds including over 200 of the most common broadleaf weeds. It is rainproof in one hour and the lawn can be mowed one to two days after treatment. It also kills dandelions and clover which some gardeners actually may want since they attract important pollinators. It also can not be used on several grass varieties including St. Augustine, bahiagrass, floratam variety, carpetgrass, centipedegrass, or dichondra.

By implementing these natural crabgrass prevention techniques along with good commercial weed killers and tender, loving care, homeowners will be rewarded with a beautiful lawn season after season.

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