How to Control Crabgrass
By: Julie Day
How do I get rid of crabgrass? I have tried all the over the counter products, and I can’t seem to get rid of it. -Dusty
To kill crabgrass, there are two things you need to know about it:
- Crabgrass Is an Annual Weed: The plants themselves are killed by fall frosts, but the seeds remain on the ground to sprout anew the next spring and summer. Each plant can produce over 150,000 seeds!
- Crabgrass Is a Grassy Weed: As the name implies, crabgrass is a grass, as opposed to a broadleaf weed. That means that any product that kill crabgrass will also kill the grass in your lawn.
Knowing these facts, keep in mind these tips for controlling crabgrass:
- A healthy, thick lawn is your first defense against crabgrass. Nurture your lawn, and keep your mower on the highest possible setting. Crabgrass seeds require bright sunlight to germinate, so they’re more likely to invade bare spots.
- Water less frequently, but more deeply, to discourage crabgrass and other weed germination.
- Use a grass catcher when mowing your lawn, to capture seed heads. Discard the clippings – you can begin composting them again once you have the crabgrass and other weeds under control.
- Use a pre-emergent herbicide in the spring and summer to prevent crabgrass seeds from germinating. Do not aerate or otherwise disturb the “shield” provided by the herbicide. Watch forsythia and lilac bushes, since the traditional time to apply pre-emergent herbicide is between the blooming of forsythia and lilac. You may also want to re-apply the herbicide in early summer.
- “Weed and feed” type products often contain pre-emergent herbicides, but some do not have high enough concentrations to be effective against stubborn crabgrass. If you’ve tried them without success, consider applying a pre-emergent herbicide separately.
- Attack clumps of crabgrass as soon as you spot them, before they have a chance to go to seed. Crabgrass produces a toxic chemical that inhibits the growth of plants around it, so it will soon start affecting your lawn grass. Pull the plants by hand, or spot spray with a post-emergent herbicide such as Round Up.
- Pull and discard the dead crabgrass plants as soon as possible, to prevent them from smothering your lawn grass.
- How to Control Weeds in Your Lawn (article)
- How to Have a Weed Free Lawn (article)
- Lawn Weed Control (video)
- How to Target Weeds (video)
- Vinegar Weed Killer (video)