How to Kill Onion Grass Weed in Your Yard

Published on: June 6, 2021
onion grass weed

Weeds are undesirable plants that tend to be very hearty and invasive. Onion grass is one of the weeds that can spread quicky through your yard and take water and nutrients away from your lawn and other plants. To control onion grass, you need to be vigilant in your efforts and make sure this weed does not overtake your lawn and gardens. Here is how to kill onion grass weed in your yard and the best way to keep it from coming back.

What Is Onion Grass Weed?

Like the name implies, onion grass is related to other common plants in the bulbous family like garlic, chives and yes, onions. It is similar in appearance to green onions, with small white bulbs and long waxy, green stalks or leaves. Often called wild onion grass, this perennial plant is considered a weed as it can overtake lawns and gardens, coming back year after year in larger numbers. Onion grass fares well in cold climates, with bulbs staying dormant during the winter and sprouting in the early spring with many other bulbs.

How to Get Rid of Onion Grass Weeds

The problem with most weeds is they are more aggressive and heartier than many of the desirable plants in your yard. Onion grass germinates and spreads easily on its own and once it is rooted, it can be difficult to kill. When determining how to get rid of onion grass, you must consider the different methods available, and which will be best for your situation. The following options are common onion grass treatments that can be used individually or in tandem to kill onion grass weed.

Pull Up Onion Grass Clumps
Onion grass grows in clumps, and you can hand pull these weeds or remove them with a hoe or trowel. This is a tedious method and not always effective if you are not careful to remove and discard the plants completely. You may need to dig down six inches to remove all the bulbs and it is important to discard the plants somewhere where the seeds will not be released into the air to spread to your yard again.
Use Herbicide
Weed killers can be used to eliminate onion grass weeds in your lawn. You can use an herbicide spray to kill small groups of onion grass clumps directly, or if the invasion is widespread, you can use an herbicide concentrate to treat the entire yard. One problem with onion grass is that it has waxy leaves that protect it from some of the effects of herbicide. It is likely you will need to use herbicide multiple times to completely rid your lawn or garden of onion grass.
Soil Acidity
Plants like onions, garlic and onion grass love acidic soil, while most grasses do not. If your soil is acidic, your lawn may struggle while onion grass weed will flourish. Fertilizing your soil and lawn to create the ideal pH balance and nutrients for your plants and grass can reduce acidity and improve the health of your lawn and garden. The right soil balance can make your yard less attractive to onion grass, especially when you have a thick healthy lawn with a strong root system.
Lawn Overseeding or Sod
If you have onion grass overtaking your lawn, it may be difficult to complete kill all the plants. The best way to kill onion grass is to make sure your grass is healthy. Aerating your lawn, overseeding and fertilizing can help restore healthy grass that pushes the onion grass out of your lawn. If there are too many of these weeds, you may consider starting from scratch with sod. Tilling up your lawn, treating with herbicide and installing new sod can put an end to your onion grass problem in your lawn.

Onion Grass Weed Prevention

How to kill onion grass weed is just the beginning. Once you kill the weeds, you need to make sure they do not come back. If you pull up onion grass or kill the weeds with herbicide, you will need to use herbicide to stop new bulbs from forming. Treating in the fall and winter can prevent new bulbs from sprouting in the spring. For lawns, keep up with grass and soil care to prevent reinfestation of onion grass from seeds blowing in on the wind.
onion grass bulb
Onion grass are one of the most invasive species of weeds and it is difficult to keep out of your lawn and gardens. If you are having difficulty removing onion grass from your yard, contact a professional landscaping company for advice or help. Your local landscaper knows how to get rid of onion grass for good with the right combination of lawn care and weed prevention methods, saving you the time and effort of doing it yourself.

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