Crabgrass Control – How To Kill Crabgrass
By: Heather Rhoades
Crabgrass (Digitaria) is a frustrating and difficult to control weed that is frequently found in lawns. Getting rid of crabgrass completely is next to impossible, but through carful lawn maintenance and persistence, you can greatly reduce the amount of crabgrass in your yard. Keep reading to learn how to kill crabgrass and using crabgrass control methods to keep it from overtaking your lawn.
Using Crabgrass Prevention to Control Crabgrass
The most effective way to get rid of crabgrass is to make sure that you don’t get it in the first place. A healthy and thick lawn is essential to be able to accomplish this.
A healthy, crabgrass free lawn will start with proper watering practices. Water your lawn deeply for long periods about once a week. Do not water frequently and shallowly, as this will encourage crabgrass to grow. Deep watering will encourage your grass to grow deep roots and they will be able to reach water better than the crabgrass weed.
Proper mowing will also help to keep crabgrass out of the lawn. Frequent mowing to the proper heights, normally between 2.5 and 3 inches (6-8 c.) depending on the type of grass, will make it more difficult for crabgrass to grow.
Appropriate fertilizing and annual dethatching will also encourage a thick and strong lawn, which will prevent crabgrass from being able to establish itself.
How to Kill Crabgrass After it is Established
Sometimes crabgrass sneaks into our lawns and flower beds, despite our best efforts. Getting rid of crabgrass once it has gotten into our yards will take time and persistence.
The most common method for crabgrass control in the lawn is to use an herbicide. Selective crabgrass killer herbicide, non-selective herbicide, and pre-emergent herbicide will all work to get rid of crabgrass. Which one you use will depend on where the crabgrass is growing and what time of year it is.
For spot treatment of crabgrass any time of year, say in flower beds and very small areas in the lawn, a non-selective herbicide will work. Non-selective herbicides will kill any plant that it comes in contact with. This includes the crabgrass and any plants around the crabgrass.
In early spring, a pre-emergent herbicide works well for getting rid of crabgrass. Since crabgrass is an annual, the pre-emergent will keep the seeds from last year’s plants from sprouting.
Later in the year, after the crabgrass seeds have germinated, you can use a crabgrass selective herbicide. Be aware, however, that the more mature the crabgrass is, the better able it is to resist the selective herbicide.
You can also use organic methods for crabgrass control. The most common method for getting rid of crabgrass organically is hand pulling. You can use boiling water as a non-selective herbicide on crabgrass as well.
Note: Chemical control should only be used as a last resort, as organic approaches are more environmentally friendly.
This article was last updated on
The Best Crabgrass Killers for Weed-Free Lawns
BobVila.com and its partners may earn a commission if you purchase a product through one of our links.
Crabgrass is an annual weed that frustrates homeowners year after year. It gets its name from how it grows—low to the ground with stems that radiate out from the center of the grass clump, resembling crab legs. When it comes to battling crabgrass in the lawn, the odds are stacked in the weed’s favor:
- It germinates when soil temperatures reach between 55 and 65 degrees Fahrenheit, the average temperature during the spring and fall seasons in most areas.
- Ungerminated seeds live in the soil for up to 30 years before sprouting.
- A single crabgrass plant can produce 150,000 seeds during the growing season.
- The weed can grow vigorously in hot, dry conditions.
- It favors the thin and bare spots in your lawn.
Although crabgrass is an annoying weed that can take over a lawn in no time, you can eradicate it with a bit of planning. The best crabgrass killer for your lawn will depend on when you apply the product and how bad your crabgrass infestation gets. Read on for our guide to navigating the available options and our top recommendations for the best crabgrass killers.
- BEST OVERALL:Scotts Halts Crabgrass and Grassy Weed Preventer
- BEST FOR CENTIPEDE GRASS:Southern Ag 006130 Atrazine St. Augustine Weed Killer
- BEST FOR ZOYSIA GRASS:Ortho Weed Be Gon Plus Crabgrass Control Concentrate
- FOR USE IN FLOWER BEDS:Preen Garden Weed Preventer
Timing to Get Rid of Crabgrass for Good
Crabgrass is a grass just like other grasses on your lawn. Applying combination herbicides won’t get rid of it. Of importance to note is that timing is important if you want to get rid of this weed permanently.
There’s a big difference between controlling perennial grass weeds and annual grasses. Annual and bi-annual grass weeds have a period of dormancy while crabgrass thrives all year round. That is why it is a perennial weed.
Tenacity killing crabgrass in my lawn.
Crabgrass will thrive even in winter (November – April) when most lawn grasses are dormant. Here are two timing tips that will help you get rid of crabgrass in your lawn:
- For spring, just before the germination of this weed, apply a pre-emergent herbicide. This will prevent the seeds from germinating on your lawn. I personally use Tenacity and have a gallon at the ready to use whenever these buggers pop up.
- In the summer, use a potent crabgrass post-emergent herbicide to kill already existing weeds in your lawn.
As you can see, understanding the life-cycle of this lawn weed is key to eliminating it for good. Here’s a summary of what you need to keep on your calendar to control this weed.
|Spring||Soil temperature = 55 – 60 degrees Fahrenheit. Crabgrass seeds germinate||Apply a pre-emergent herbicide for crabgrass control.|
|Mid-summer – Fall||Warm weather crabgrass is flowering and producing seeds.||Apply a good post-emergent herbicide, or uproot.|
|Winter||Cold temperatures, dormant crabgrass seeds.||Prepare to apply a pre-emergent.|
8 Killer ways about ‘How to Get Rid of Crabgrass’
So you really hate Crabgrass and you need help to get rid of it? Believe it or not, it’s possible and in this article, you will read about how to do that.
The attractive and innocent-looking crabgrass can rapidly become the voracious bogeyman that can quickly eat your entire lawn. It can become a big problem during the summer because, in hot and dry conditions it’s able to grow forcefully before dying in the fall. A single weed can give out thousands of seeds that will be ready to grow in the following summer.
Actually, there are three types of people who want to get rid of Crabgrass:
- Farmers who grow crops in the summers for cattle.
- Environmental firms cleaning up oil spills.
- Homeowners with a lawn full of crabgrass.
We are writing this article for everyone.
It’s true that Crabgrass doesn’t grow overnight, and you won’t get rid of it quickly either. But it’s possible to control and prevent its appearance, again and again, each year.
So you can take care of this innocent-looking devil right now just by following our tips. Most of these ways are for getting rid of it naturally. Without further ado, why don’t you start reading them:
1. Water more deeply but less frequently
One of the common mistakes every homemaker make is to water their lawns frequently and lightly. You just need to do a deep watering of your grass every few days, this discourages crabgrass. Deep watering encourages the grass to put down roots deeper.
2. Regularly use fertilizers for your grass type
Fertilizers actually encourage the growth of the grass, and the flush of new lawn grass will horde out crabgrass seedlings.
3. Select Grass Species suitable for your climate
If you choose a grass species according to your area’s climate, then it will easily set down roots and grow healthy. In return, it will provide less room for crabgrass to grow in your lawn.
4. Don’t let any garden spots uncovered for long
If possible, try to avoid this, because if you leave some open spots uncovered for long, then crabgrass will take root. You can fill these uncovered spots by overseeding in fall.
5. Use homemade eco-friendly crabgrass killer
There are lots of eco-friendly homemade crabgrass killers that you can use to get rid of crabgrass. Some of them are:
- Vinegar – Use Vinegar or White vinegar on young crabgrass to kill it.
- Boiling Water – Just boil some normal water and spray on the area with crabgrass.
- Bleach – Put some bleach in a spray bottle and spray it where you wish to remove the crabgrass.
- Salt – You can drop a pinch of salt on the spot where you want to kill crabgrass
- Rubbing Alcohol – Spray Rubbing Alcohol on the crabgrass and it will suck the life out of it to kill it.
- Cornmeal – Corn gluten is crabgrass birth control. It doesn’t kill the weed but controls it from developing again.
- Newspaper – Put 4 thick sheets of newspaper over the area with crabgrass and it will die due to lack of sunlight
Note: No doubt that the areas treated with all the homemade weed killers work fine, but the area treated with boiled water still have no crabgrass growing
One of the most important tip to get rid of crabgrass is to mow high. This means you need to leave the height of the grass about 2-3 inches. Doing this lets the grass save its own turf better, preventing crabgrass seeds getting any light which they require to germinate.
7. Use Herbicides
After giving your best, if you find that you’re not able to stop crabgrass from growing, then you can directly spray herbicides on the weed.
8. Remove Dead Crabgrass
Removing dead crabgrass plants from the field is as important as killing the weed. So, regularly look for dead grass and remove it from the field as it helps to recover lawn grass.
Additional Tip: If you regularly check your lawn and give more attention at a certain interval of time, then you can easily maintain your beautiful lawn grass.
Why don’t you try these tips and let us know whether any tip helped you get rid of Crabgrass? Also, don’t forget to check this article again for more tips. You can use the comment section to let us know your favorite tip to get rid of Crabgrass.
FAQs About Your New Crabgrass Killer
When it comes to using pre-emergent and post-emergent crabgrass killers, timing is everything. Be sure to read the product’s label thoroughly and follow the manufacturer’s directions for the best results. Here are some common questions that arise when using a crabgrass killer:
Q. When is the best time to apply crabgrass pre-emergent?
Apply crabgrass pre-emergent when the soil temperature is around 50-degrees. Killing the weed might require a second application in areas with long growing seasons. Follow the manufacturer’s directions for timing.
Q. Will heavy rain wash away pre-emergent?
No. Rain activates pre-emergent by carrying it into the soil. However, digging and pulling existing weeds after applying the pre-emergent can reduce the product’s effectiveness.
Q. How do you apply a crabgrass killer?
Apply post-emergent crabgrass killer in the morning, on a dry day. Treat only the affected areas of the lawn. Coat the crabgrass evenly.
When to Kill Crabgrass
It helps to familiarize yourself with the plant's life cycle to effectively eradicate crabgrass. When spring soil temperatures (at a depth of 2 to 3 inches) reach 55 to 60 degrees Fahrenheit, crabgrass seeds start to germinate. From mid-summer through fall, the plant produces more seeds in an attempt to increase its numbers. Once the first frost arrives, the plants themselves (but not the seeds) are killed.
When organic methods are used, gardeners must wait until the seedlings are big enough to hand pull, roots and all. While crabgrass doesn't spread via its roots, it's still essential to remove the whole plant in the spring before amending the soil and reseeding.
Pre-emergent herbicides (also called "crabgrass preventers") come in either a granular or a liquid form and kill crabgrass seedlings right as they germinate. Think of pre-emergent herbicides as forming an invisible shield across the soil's surface that stops emerging crabgrass dead in its tracks.