How to Get Rid of Onion Grass: A Comprehensive Guide

We may earn a commission for purchases made through our links.

Do you have a patch of onion grass taking over your lawn? Are you wondering how to get rid of it before it spreads even more? Look no further than this comprehensive guide on what onion grass is and how to banish it for good!

What is Onion Grass?

Onion grass (Allium vineale) is a perennial weed that grows from underground bulbs or bulblets. It resembles green onion or chives, but unlike those plants, onion grass is difficult to control because it spreads quickly and can produce thousands of seeds each year.

While it’s not harmful to humans or pets, onion grass can be a nuisance to deal with, especially if it’s crowding out your desired plants. Here’s how to get rid of it:

Identify the Problem

Before you can eliminate onion grass, you need to know what you’re dealing with. Here are some ways to recognize it:

  • Onion grass has a distinct odor when crushed, similar to garlic or onions.
  • It produces small, white or pinkish flowers in the summer.
  • The leaves are long, thin, and between 1/8 and 1/4 inch in diameter.
  • The stems grow up to 2 feet tall, and the bulbs are about 1/4 inch in diameter.

Control Methods

Once you’ve confirmed that onion grass is the root of your problem, it’s time to take action. Here are several methods to controlling onion grass, ranging from easy to more difficult:


If you only have a small patch of onion grass, hand-pulling the bulbs is your best bet. Make sure to get as much of the bulb and roots as possible to prevent regrowth.


If you don’t mind sacrificing a small patch of lawn, you can try smothering the onion grass with a layer of thick cardboard, plastic sheeting, or landscaping fabric. This method prevents light from reaching the bulbs, suffocating them over time.

Chemical Herbicides

For large infestations, chemical herbicides may be necessary to control onion grass. Look for products that contain glyphosate or pelargonic acid, which are effective on perennial weeds. Follow the manufacturer’s instructions carefully and don’t use too much – herbicides can harm desired plants if overapplied.

Prevent Future Growth

After you’ve eliminated the onion grass, it’s crucial to take steps to prevent it from returning. Here are a few ideas:

  • Regularly mow your lawn and avoid letting it get too long, as onion grass thrives in tall grass.
  • Apply a pre-emergent herbicide in the spring to prevent onion grass from germinating.
  • Dig up any bulbous weeds as soon as you see them before they have a chance to spread.


Q: Is onion grass harmful to pets or humans?
A: No, onion grass is not harmful to pets or humans, but it can be a nuisance when it takes over a lawn.

Q: What’s the best way to control onion grass?
A: The best way to control onion grass depends on how severe the infestation is. Hand-pulling, smothering, and chemical herbicides are all effective methods, but they each have their drawbacks.

Q: Does regularly mowing my lawn help prevent onion grass?
A: Yes! Onion grass thrives in tall grass, so keeping your lawn mowed to a reasonable height can help prevent it from spreading.


Onion grass may seem like a difficult weed to control, but with the right tools and methods, it’s possible to eliminate it from your lawn. Remember to properly identify the weed, choose the best control method for your situation, and take steps to prevent future growth. Happy weeding!


Please enter your comment!
Please enter your name here