How to Kill Crabgrass – Best Way to Keep It under Control


Crabgrass is a troublesome weed that usually invades gardens and lawns. It steals nutrients and valuable moisture from the soil competing with other plants of value such as flowers, vegetables, and lawn grasses. Although it is a real grass, a keen eye may be able to spot it even when among other types of grasses. Its light-green leaves are rough and pointy, and it spreads quite aggressively. A single seed can result in thousands of plants in a single season.

Wondering how to kill crabgrass without harming your valuable plants? Do not worry. Although stubborn and aggressive, you can still manage to keep the weed under control. This article outlines several effective ways on how to kill crabgrass.

1. Pluck out by hand

Pulling the crabgrass out using your hands isn’t always the most effective or easiest solution. But sometimes it’s the only option. What do you do when its midsummer and your lawn is already full of crabgrass for example?

How to do it?

There isn’t really much you can do once crabgrass gets a foothold in your garden. But pulling it out by hand before it goes to seed will help reduce its growth in the next year. If the weed is difficult to remove by hand, water the ground. That will loosen the soil making it easier to pull the grass out.

2. Mulching

It won’t matter how many times you pull up the crabgrass. As long there are seeds in the soil, they will still sprout year after year. Spreading mulches can be a useful solution. If you cover the ground with mulch, it will block out the light and prevent sprouting.

How to do it?

Spread a 3-6-inch layer of course mulch or a 2-3 inch layer of fine mulch. Course mulches include shredded bark, wood chips and straw. Some examples of fine mulch are leaf fold, well-rotted manure and garden post. Make sure to top up the layer annually or semi-annually when it starts to thin out.

3. Soil Solarization

This solution works best when you want to turn a crabgrass infested area into a garden. The process involves covering the ground with transparent plastic helping to heat up the soil up to 18 inches below the surface. Weeds and other pests will die since they can’t survive in such conditions.

How to do it?

First, dig a 4-6 inch deep trench around the area. Water the ground in the middle until the moist soil runs 12 inches deep. Place the transparent sheet over the soil and cover the edges of the trench with soil. The materials should be 1-4 millimeters thick.

4. Herbicides

There are several types of herbicides to choose from if you want to get rid of crabgrass in your garden. If you’re not worried about killing ornamental plants, you can use a broad-spectrum herbicide. It will kill all the weeds and any other plants it comes into contact with.

How to do it?

If you don’t intend to harm ornamental plants, try a selective herbicide that will only target grasses without causing any harm to other plants in your garden. Since crabgrass will sprout year after year, you should use a pre-emergent herbicide to control the weed before it even emerges. If you don’t like using chemicals, you can learn how to kill crabgrass using natural herbicides below.

5. Natural herbicides

Want to learn how to kill crabgrass naturally, try natural herbicides. If you don’t want to spray chemicals in your garden, several organic herbicides can also be as effective.

How to do it?

Corn gluten meal is one such example. It works as a pre-emergent herbicide by interfering with the development of root systems of weeds. Agralawn crabgrass killer is another natural herbicide made from plant-based ingredients. Cinnamon bark is the active ingredient. It helps to kill large crabgrass weeds that other post-emergent herbicides can’t.

6. Avoid redistributing seeds

Crabgrass is a very aggressive weed, and a single seed is enough to cause a full-blown infestation. That’s why it’s quite essential to know how to dispose of the grass after weeding it out.

How to do it?

After clearing your garden, put all the plants and clippings in a bag and discard them immediately. Never throw away the weed in a compost pile or, worse yet, use it as mulch in your garden. But if you have to throw in compost, put the plants in a bag and tie the top. Leave it out in the sun for four to six weeks. The heat will kill any seeds present.

7. Fertilize your garden in the fall rather than in spring

Crabgrass is an annual plant, and it dies off completely when frost comes along. If you fertilize the garden right after this happens, only your valuable plants will benefit from the fertilizer since the weed will be long gone.

How to do it?

Fertilizing your garden during spring will give you completely different results. Spring is usually the time when crabgrass seeds are germinating. If you apply fertilizer at this time will provide the weed with all the ammo it needs to take over your garden.

8. Water more deeply but less frequently

Many people often make the mistake of watering more frequently but lightly.

How to do it?

Watering the lawn up to 4-6 inches deep is good for the grass. Allowing the ground to dry out between watering will help it develop deeper root systems. Light watering will lead to shallow surface roots that will dry out very quickly. Additionally, deep watering will discourage crabgrass. If the soil is left to dry between watering, the shallow-rooted crabgrass will find it difficult to germinate.

In conclusion

Crabgrass is a very stubborn weed. It will invade your lawn and garden and take way nutrients and moisture from valuable plants. Luckily, you can learn how to kill crabgrass by following any of the methods listed above. But ultimately, prevention is better than cure.

If you can keep the seeds from germinating in the first place, the better. It is harder to get rid of them when they have already invaded your garden. Has crabgrass become an annual bother in your lawn or farm? Follow the above methods on how to kill crabgrass and get rid of the weed once and for all.


Jonathan E. Bass

Graduated from Middle Tennessee State University. I am currently a gardener. I have a small garden behind my house. I love it.

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