The best defense against crabgrass is actually a healthy lawn. The more healthy and deeply rooted your turf is, the harder it becomes for invasive weed species to take over. Following a consistent lawn care program that includes proper mowing, watering and fertilization practices is the best way to prevent weeds.
How to treat crabgrass prior to germination (pre-emergent)
Weed prevention prior to germination is the next best way to take care of weeds, including invasive grassy weeds like crabgrass. The ideal time to treat crabgrass is in the prevention stage. Crabgrass can typically be prevented with pre-emergent weed control, but you have to perform the application at the right time and with the right product.
Cool Season Grasses
At Canopy Lawn Care, we perform pre-emergent weed control in 2 split applications. For cool season grasses like fescue, the first is in late winter / early spring timeframe (January or February). During this application, we also apply fertilizer, again focusing on overall lawn health. The second application will be in March.
Warm Season Grasses
Warm season grasses also receive a split application, however, at Canopy we perform them farther apart to prevent both summer annual grassy weeds (crabgrass) and winter annual grassy weeds (poa annua, etc.), which are more prevalent in warm season turf varieties.
If you plan to do your pre-emergent weed control yourself, you will need to exercise patience and persistence in order to get the job down. Waiting for the right window is critical to successfully suppressing crabgrass. After the first couple mows of the season is usually the optimal sign. However, unavoidable factors like the weather can play a big role as well. Make sure that you read the product specifications for your pre-emergent. Most pre-emergent herbicides should be applied when the temperature begins to reach 60 degrees.
Here are a few basic tips…
If there are heat or water restrictions, be sure to apply at the right time based on those specifications.
Ensure that the product you apply is safe for your lawn. Some products are not safe for certain grass types.
If you have recently seeded your lawn, do not apply pre-emergent until you have mowed the lawn 3 times. This will prevent damage to the new growth.
Apply the herbicide with a spreader and focus on a uniform application throughout the lawn.
If crabgrass has already appeared in your lawn, it is too late for pre-emergent weed control. Focus on control through post-emergent measures.
If you plan to dethatch or aerate your lawn, do so prior to applying pre-emergent herbicide or after the soil barrier has had enough time to be effective. Ultimately, this seasonal activity will depend on your turf type.
How to treat crabgrass after germination (post-emergent)
Crabgrass can be treated following germination, but that is when it becomes trickier to get rid of. This persistent grassy weed can quickly spread throughout your lawn. Post-emergent herbicide can be effective, but it will likely take multiple applications to remove crabgrass.
A few tips for effective post-emergent treatment…
If the crabgrass plant is still young and you do not notice seed heads, then it is ok to pull the crabgrass.
Do not pull fully grown crabgrass plants that have sprouted their seed heads. Adult plants can shed thousands of seeds and pulling the plant will risk spreading the crabgrass throughout your lawn.
Crabgrass tends to like areas that stay warm and you will frequently find it along the edges of driveways or sidewalks. Keep an eye on these areas and treat them as soon as you see the weeds appear.
It is important to choose the right product. Be sure to pick a post-emergent herbicide that is safe for your turf type and also effective on crabgrass.
Follow the product instructions and watch the treated area closely following application.
Make sure that your lawn is receiving adequate moisture prior to application. If conditions are hot and dry, be sure to water your lawn within a day or two following application.
Crabgrass will likely require multiple applications of herbicide before the plant will die off.
Persistence Pays Off
Staying on top of lawn care best practices is ultimately what will help you keep crabgrass at bay. If crabgrass has been a problem on your property, start by implementing pre-emergent each spring. Then, focus on spot treating areas that pop up following germination. Those efforts, combined with a strong focus on the general health of your turf should help you on your way to freedom from crabgrass!
Do have questions or concerns that we can help with? Canopy Lawn Care is available via email, text or phone and we would be happy to serve you!