How to Organically Prevent and Treat Crabgrass

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What You'll Need
Organic herbicide (citric acid and clove oil)
Clear plastic sheets
Lawn mower
Corn gluten
Garbage bag

Crabgrass is a common weed that has become the bane of existence to a lot of lawn-lovers. With seeds that can live in soil for years, crabgrass outgrows other grass varieties and has been known to harm nearby plants. Although crabgrass can be a pain to remove, there are ways you can rid your lawn from this troublesome pest without turning to harsh chemicals. From crabgrass removal to preventing germination, here are ways you can—organically—treat and prevent crabgrass from taking over your lawn.

Prevent Seeding

Remove as much of the crabgrass as possible before the plant can spread seeds and reproduce. Large patches can be treated with an organic herbicide, such as a mixture of citric acid and clove oil, though you should be careful when applying it to the lawn. If you cannot remove the crabgrass early in the season, mowing can prevent it from going to seed. When removing the crabgrass, pull it out from the root and try to get as much of the plant as possible.

Discarding Plants

You should immediately place crabgrass clippings and plants inside a garbage bag to prevent distributing the seeds throughout the lawn. Avoid using the clippings as mulch or placing them into a compost pile. If you want to recycle the clippings, you can place the garbage bag in the sun for a month or two. The heat from the sun will kill the crabgrass seeds and you can then use the rest of the material for mulch.

Stopping Germination

A lawn mower cutting a lawn to prevent the growth of crabgrass.

The best way to prevent a crabgrass infestation is to have a healthy lawn. Grass that is thick and healthy will prevent crabgrass seeds from germinating. Keeping a healthy lawn starts with mowing. Always mow your grass within the recommended height range. This will make it harder for the crabgrass to compete with the rest of the grass and prevent it from spreading seeds. As a rule of thumb, you want to keep the grass higher than the crabgrass as this will help choke it out.

To slowly kill off existing crabgrass, mow once a week and keep the grass from growing higher than three inches. Mowing frequently will slowly reduce the amount of crabgrass because it prevents the plant from spreading seeds. Be careful not to cut the grass shorter than its recommended height as a healthy lawn is the best defense against crabgrass.

Watering Techniques

A sprinkler watering a lawn to prevent the growth of crabgrass.

Unlike other grass varieties, crabgrass has shallow roots. To take advantage of this, water for long periods of time, but not very often. This will help the rest of the lawn stay healthy while drying out the top level of soil, which will help kill the crabgrass. Just be careful that the rest of the lawn is receiving plenty of water to remain healthy.

Spring Preparation

Crabgrass is hardest to control in the spring when the rest of the lawn is just starting to grow. To help prevent the crabgrass from taking over, spread some corn gluten across the entire lawn. Corn gluten will make it harder for the crabgrass to germinate and provides nitrogen for the rest of the grass. Not only does this method help kill the crabgrass before it takes hold, but it also provides nutrition for the rest of the lawn.

Solar Power

If none of these methods work, try using the power of the sun to kill off the crabgrass. Start by mowing the problem area as short as you can and then water it thoroughly. Take a square of clear plastic and cover the area, sealing the edges of the plastic close to the ground. Over the course of the next month or so, heat from the sun will kill all of the crabgrass seeds underneath. Once the crabgrass is gone, remove the plastic and reseed the area to match the rest of the lawn. This method takes a little more time and effort, but will produce great results.