Crabgrass is a notorious weed across the United States, especially in lawns. It is an annual grassy weed. It has pale, bluish-green blades that can reach 2-5 inches high and are sometimes slightly hairy. Plants grow in flat, broad clumps that crowd out preferred plants, especially turf grasses in summer. The prostrate stems radiate out like the legs of a crab (hence the name) and root as they go. BioAdvanced offers numerous crabgrass killer options.
Spray when weeds are small and actively growing when temperatures are below 90 degrees Fahrenheit, 85 degrees Fahrenheit for Bermudagrass.
On lawns without harming lawn grasses - Bermudagrass, Buffalograss, Kentucky bluegrass, ryegrass, fescue, zoysia, bentgrass.
Application on Bermudagrass may cause temporary yellowing or discoloration but full recovery can be expected.
Do not use on Bahiagrass, Carpetgrass, Centipedegrass, St. Augustine including Floratam or Dichondra.
Spray when listed grass weeds are small and actively growing and temperatures are below 90 degrees F.
To control Bermudagrass, up to seven applications spaced one month apart may be required. Make the first application in the spring when the Bermudagrass begins to green up. Repeat the following growing season if necessary.
Do not make more than three applications per year.
Before treating new or renovated lawns, new grass seedlings must be at least 1 month old, 3 months for Kentucky bluegrass). Kentucky bluegrass sod must be at least 1 month old since installation.
Treated fescue and perennial ryegrass lawns may be re-seeded immediately after application, however, wait 3 weeks after application to Kentucky bluegrass before reseeding.
Do NOT use around these ornamental plants: barharbor juniper, philodendron, pittosporum, podocarpus, salvia.
On lawns without harming lawn grass.
Do not use on St. Augustinegrass including floratam, Bermudagrass, bentgrass, zoysiagrass, centipede or bahia lawns.
Crabgrass sprouts from seeds in early spring and summer from seeds deposited potentially over many years. One plant can produce thousands of seeds that germinate over many years in your lawn. The seeds can also find their way into sidewalk and driveway cracks, along with flower beds and vegetable gardens. Germination begins when soil temperatures reach 55-60°F and stay there for 7 days. Germination continues until temperatures reach about 95°F. Crabgrass likes to germinate in bare areas of the lawn. Flower heads consist of slender, arching, finger-like spikes originating from the near the top of the stems. Crabgrass is very fast growing in warm weather. The foliage usually stands out as lighter green than most turf grasses. Plants die in fall.
The first step in controlling Crabgrass is to maintain a healthy, vigorous lawn with proper fertilizing, watering and mowing. Lawns that are mowed too low are particularly susceptible to invasion by Crabgrass. Check with your local Cooperative Extension System office, but the heights for most Fescue and Bluegrass lawns should be 3 inches.
Existing Crabgrass plants can be controlled with appropriately labeled post-emergent herbicides. Be sure to check the label as some post-emergent herbicides cannot be used on all turf types. They are most effective when plants are young. The combination of properly-timed, pre-emergent herbicides and post-emergent herbicides are key to prevention. Your local Cooperative Extension System office can provide information on proper timing of pre-emergent applications in your area. You can also use a weed & feed. 3-In-1 Weed & Feed For Southern Lawns is a pre-emergent that prevents Crabgrass for up to 6 months.