We all look forward to the green lawn and blooming flowers that warmer spring temperatures provide. What we don’t look forward to are all the weeds, including crabgrass, that those temperatures also contribute to. Luckily, with a little bit of prevention and some basic knowledge, you can learn how to control crabgrass so you can have that beautiful yard you have dreamed about.
Crabgrass prevention is vital if you want to prevent the plant from taking over your lawn. An essential aspect of crabgrass control is understanding how crabgrass works. Crabgrass starts to spread across your lawns during the hot months of the summer.
Crabgrass seeds, though, are produced between the middle of summer until the early fall, and the problem is that one plant produces a couple thousand seeds. The first frost kills the crabgrass plant, but not the seeds. They begin to germinate as the temperatures rise; therefore, effective crabgrass prevention starts before the seeds begin to grow.
Useful Tips and Ideas for Basic Crabgrass Prevention
Crabgrass, also known as Digitaria, is an annual weed that received its name from the way it grows. The easiest way to spot this weed is the way it grows in clumps with stems of grass that grow out like crab legs. Crabgrass is a battle for everybody looking to maintain a beautiful walkway, lovely flower beds, or a well-manicured lawn.
How to Control Crabgrass Before It Emerges
Once crabgrass is established in your yard, getting control of it requires a lot more than just primary lawn care. Your best line of defense is preemergence herbicides to kill the crabgrass seedlings before they begin to germinate. Whenever you are applying pre-emergent herbicides, always follow the label directions for the best results.
When applying herbicides, timing is vital. When you apply the product varies from one region to the next, as you need to consider the weather patterns. Many people use Forsythia blooms as a way to determine when crabgrass will germinate, but that is not always accurate.
Apply your herbicide product once soil temperatures are above 60°F or when trees begin to bud in the early spring. Apply the product evenly across the lawn, as any missed spots allow crabgrass to grow.
Never use a pre-emergent herbicide on a newly seeded lawn or a lawn where you have just laid sod. With a freshly seeded lawn, wait for at least three mowings before applying, or you risk killing your lawn seeds. Once applied, do not aerate or de-thatch your lawn to prevent breaking the chemical barricade put in place.
Knowing the right pre-emergent herbicide to use when treating crabgrass is difficult, as there are so many to choose from. Dimension, which includes dithiopyr as an active ingredient, is safe for almost all lawn types.
Tuperson, which uses siduron as its active ingredient, is safe for germinating seeds, so it is an excellent choice for new lawns. If you don’t want to use chemicals opt for a preemergence herbicide, such as corn gluten; not only does it control crabgrass, but it also fertilizes your lawn.
Crabgrass Control After It Emerges
Pre-emergent herbicides will not kill crabgrass once it appears in your yard. If you missed the window to apply a pre-emergent herbicide, you need to utilize post-emergent herbicides to get rid of crabgrass after it appears. These herbicides are only good at killing the plant once it sprouts.
As with all chemicals, read and follow the manufacturer’s instructions when applying. How you apply a post-emergent herbicide to your lawn depends on the variety of grass you have. Before applying post-emergent herbicide, always check the weather forecast.
Only use on sunny and calm days with zero percent chance of rainfall. Rain washes away the product, rendering it ineffective. For optimal results, outside temperatures should range between 60 and 90°F. Apply the product after the morning dew has dried, but while the soil is moist.
For cool-season grasses, such as Kentucky bluegrass and tall and fine fescue, use a post-emergent herbicide that features quinclorac to kill the crabgrass. For warm-season grasses, like St. Augustine and Bermuda, use Roundup for Lawns. This is a selective herbicide that is safe to use in the late summer to control crabgrass and other common weeds found in your lawn.
Watch your lawn after application. Brown grass means too much of the product was applied. Water the area well to help dilute the herbicide and to hopefully salvage your lawn.
Any new crabgrass plants require immediate spot treatment. For established plants, treat the problem areas with a second herbicide application no sooner than four days after the first treatment, but no later than seven days.
Controlling Crabgrass with a Homemade Weed Killer
If you are using a homemade weed killer, do so cautiously. Many homemade weed killers don’t just target weeds but affect the plants and soil around them. On crabgrass, use the best homemade weed killer recipes as spot treatments rather than a broad application.
Mix Borax, dish, and vinegar inside a sprayer. Use a sprayer that allows you to choose between spray and stream for precision control.
On a sunny day, use the stream selection to spot treat crabgrass throughout the lawn. Be careful not to overspray as the weed killer will kill everything else around it. For larger problem areas, swap to the spray selection and let loose.
Organic Crabgrass Prevention
Aside from corn gluten, the only natural way to remove crabgrass is manually. For best results, soak the problem area with a garden hose or a sprinkler. Allow the water to soak into the ground for about 30 minutes and then remove the crabgrass, making sure to get everything, including the roots.
To make crabgrass removal easier, use a weeding tool or a pitchfork. Before reseeding the bare spots, work some organic compost into the soil. Once you have laid out the new seed, cover with straw to keep the moisture in and the birds out.
Water the new seeds every day until sprouts begin to emerge. As soon as the new grass is long enough to start mowing, cut back on the daily watering, and begin to water deeper. Maintain your new lawn to prevent crabgrass from coming back.
If crabgrass has fully invaded your lawn, use a crabgrass killer across the entire yard, but do not try this method during the summer months. If you plan to renovate your yard by removing everything, it’s best to wait until next year.
A Healthy Lawn is the Best Crabgrass Preventer
One thing we have learned is that with all lawn grasses, weed control is best done by maintaining a healthy lawn. If you have a thick lawn, weed infestations of any kind aren’t able to take hold. To prevent grassy weeds or various broadleaf weeds from invading your yard, use the correct mowing height, which may require adjusting your mower.
Crabgrass germination requires direct sunlight; longer grass blades shade the soil, preventing the sunlight from reaching the seeds. When mowing the lawn, do not cut more than one-third of the grass blade’s length at a time. Cutting too much at once harms the grass, plus allows more light to reach the soil, increasing the chances of germination.
Do not use infrequent, shallow watering; instead, practice heavy watering only when needed. Periodic but deep watering encourages root growth in various grass types, and it is that deep root system that allows for healthy turfgrass.
Lawn fertilizer is an essential step in maintaining a healthy lawn. No matter what season grasses the lawn features, apply fertilizer three to four times a year to stay on top of all lawn weeds.
In the spring, apply a fertilizer with crabgrass control to kill the weed seeds before they germinate. When looking for the best fertilizer with crabgrass preventer in it, look for ones that contain pendimethalin or prodiamine.
Thank you for reading our crabgrass control post. If you found any of our crabgrass prevention tips and recipes useful, please take a minute to share these tips and ideas with others on Facebook and Pinterest, so they can learn how to control crabgrass, too.