How to Get Rid of Onion Weed

Make onion weed a thing of the past with this simple guide

Co-authored by Lauren Kurtz

Last Updated: May 23, 2022

Onion weed, or Asphodelus fistulosus, is an invasive plant with long, cylindrical leaves and white flowers.^{[1]
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Trustworthy Source
US National Park Service
Agency responsible for the maintenance and promotion of national parks and monuments
Go to source} Onion weed can be eliminated with suitable herbicides, or by using natural methods, like pulling or smothering. You’ll have to be persistent to get rid of this surprisingly resilient weed, but with patience and time, it can be done.

Method 1

Method 1 of 2:

Eliminating Onion Weed

1
Pull the weeds out of the ground. Hand pulling onion weed out of the ground is an easy, immediate option. If you're looking for a natural way to get rid of onion weed, hand pulling is an effective method.^{[2]
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Trustworthy Source
US National Park Service
Agency responsible for the maintenance and promotion of national parks and monuments
Go to source}
2
Use an herbicide. Onion weed can be effectively and fairly safely eliminated by using an herbicide containing glyphosate. You should follow the directions given with the herbicide, but in most cases you simply spray the herbicide on the weeds you want to eliminate.^{[3]
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- Please note: The WHO considers glyphosate to be a probable human carcinogen. Its use is prohibited in some states and countries. Please check with your local laws and use caution if handling this chemical.
- Always spray on a clear, non-windy and dry day.
- Always wear protective gear when using an herbicide.
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3
Cover the area in plastic for a herbicide-free option. Take a sheet of opaque black plastic that is large enough to cover the area infested with onion weed. Use several sheets if necessary. Hold the plastic in place with rocks or stakes, and leave it there for several weeks.^{[4]
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- By cutting off light that the plants need to survive, this method will eventually kill the weeds.
- This method will probably also dry out the soil in the area, and may kill grass or other plants along with the onion weed.
- Plan it to take a year or so for the soil and area to return to normal.

Method 2

Method 2 of 2:

Removing Wild Onions

1
Dig bulbs out of the ground. You can pull wild onions out of the ground, but merely yanking on the green stalks will leave the bulbs in the ground. This means that before too long, the weeds will return. To really eliminate the weed, you will have to take a small trowel and dig the whole plant out of the ground, bulb and all.^{[5]
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2
Choose an herbicide. Only certain herbicides are effective against wild onions. Look for “postemergence” ones, meaning herbicides that are sprayed on the plants after they sprout options include herbicides containing:^{[6]
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- Imazaquin
- A combo of 2,4-D, dicamba, and mecoprop (MCPP) in them.
- Glyphosate (useful only if you have a small number of wild onions to eliminate)
3
Attack persistently. Because wild onions have long, smooth leaves, it isn’t easy for herbicides to stick. This means that you will most likely have to spray several times a season, possibly for more than one year. Don’t give up!^{[7]
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- Spray in late fall and again in late winter or early spring.
- Mowing before you spray might help.
4
Try a natural method instead. If you want to avoid herbicides, dig up the bulbs first and discard. Then spray ordinary white vinegar in the hole. Refill the holes with new topsoil.^{[8]
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- You can also try smothering wild onions under black plastic, in the same way as you would for onion weed.

Community Q&A

Question

Will microwaving onion weed bulbs kill them? If so, how long for?

Community Answer

The important thing is to get the bulbs out of the ground and discard them.