Wild Onion Control: How To Get Rid of Wild Onions

This page is an expert guide on getting rid of Wild Onion from your property using the products and methods suggested by our experienced lawn care specialists. Follow this guide and use the recommended products and we guarantee you will be successful in eliminating Wild Onion.

Garlic and onion may make great additions in the kitchen if you are cooking some Italian food, but on your lawn? Not so much. Wild Onion (and the very similar Wild Garlic) are two pesky weeds that are definitely a sight for sore eyes--and thats without chopping and dicing them.

Wild onions (Allium canadense) are relatives to the varieties of garlic and onions we buy from the grocery store but with a glaring difference; these winter perennials creep up usually where they are not wanted in flower beds or lawns.

Continue reading to learn more about wild onion and how you can remove it from you property using professional lawn care products and advice by Solutions Pest & Lawn lawn care experts.

Identification

Before proceeding with control methods, it's important to first properly identify the plant to confirm whether it is wild onion. Misidentification can lead to using the wrong herbicides, which will be ineffective against the weed, costing you time and money. Below are some identifying traits of Wild Onion.

• Wild onions are perennial grass-like plants that grow from bulbs. They grow actively in the cooler weather of fall and spring, usually up to 18 inches in height. When dug up, the bulbs are covered with a fibrous membrane and have short roots.
• During spring, the weeds bolt and grow flowers in umbels. Each individual flower resembles a six-pointed star and ranges from pink to white in color. From these flowers, aerial bulblets are formed and eventually drop to the ground to form new plants. The older plant then dies.
• Several plants are easily confused for wild onion, like wild garlic and other more toxic plants. It’s important to distinguish wild onion from other weeds, as that may impact your approach to treatment.
• To tell wild onions from wild garlic, check out the leaves. While wild onions grow flat leaves, wild garlic grows tubular leaves that are hollow on the inside. To tell wild onions from toxic lookalikes, dig up one of the bulbs. The bulb of a wild onion will be covered in its fibrous membrane, while the toxic lookalikes will lack this.

Use our description and image above to help you to identify wild onion on your lawn. If you are not totally sure and need assistance with identification, contact us and we will properly ID the plant for you as well as give you the best product recommendations to control your weed.

Even though wild onions are closely related to the cultivated onions we buy in grocery stores, unless you’re a trained foraging professional, we advise you to not dig up wild onions for consumption.

Inspection

After you have confirmed that you are dealing with wild onion, you should move on to Inspection to pinpoint the areas where the weed is growing and the conditions that is helping Wild Onion to thrive.

Where to Inspect

Wild onions have a wide distribution throughout the United States. If you suspect weed activity in your lawn, look for patches of differently colored turf. These plants are often a different shade of green from your normal turf grass.

What To Look For

Wild onions grow actively in cooler temperatures when most turf grasses become dormant. When the weather cools in fall, be on the lookout for taller patches of grass that have not lost their color to dormancy. In spring, look out for early flower formation. If bulblets have formed, control methods may only treat the existing plants and not any new plants that have yet to sprout.

Treatment

After identifying your weed and inspecting your property, it’s time to start treatment.

Before starting any treatment, be sure to wear your personal protective equipment or PPE, and remember to keep people and pets out of the treated areas until products dry completely.

If you have a few wild onions growing on your lawn, then manual pulling is manageable enough. Keep in mind that it’s easy for the plant leaves to break off from the bulb, and that other bulbs are often left in the ground to grow.

In lawns, mowing will also help, but not kill the plants entirely. With proper, consistent lawn care, weeds will eventually weaken and choke out.

For large infestations of wild onion weeds, the best method of control is to apply a post-emergent herbicide that’s labeled to not injure your lawn’s native turf grass.

Step 1: Mix And Apply 2,4-D Amine

In cool-season grasses, we recommend 2, 4-D Amine. The labeled application rate for this product is 3.16 pints of concentrate per 1 acre. For smaller applications, this breaks down to 1.1 fluid ounces of concentrate applied over 1,000 square feet.

In warm-season grasses, we recommend Fahrenheit Herbicide. For spot applications, mix 0.2 ounces of the product per 1 gallon of water to apply over 1,000 square feet. Keep in mind that when making applications over St. Augustinegrass, Bermudagrass, or Zoysiagrass, temporary stunting or chlorosis may occur.

For either of these products, we recommend you mix and apply your herbicide with a handheld pump sprayer. Because wild onion leaves are waxy, we recommend you use a surfactant like Nanotek to enhance the effectiveness of your treatment. Nanotek is a non-herbicide product designed to improve the adhesion and penetration of pesticides onto treated surfaces. When using Nanotek, just add 1 fluid ounce per 1 gallon of solution.

Spot-treat any wild onion plant you’ve found during your inspection. Use a fan or cone spray pattern to ensure the leaves are fully coated, and spray the weed to the point of wet but not runoff. Be sure to spray on calm days when temperatures are not too hot and when wind speeds are low to minimize drift.

Step 2: Reapply

When applied properly, affected weeds will yellow and begin to die. A follow-up application may be necessary if signs of recovery are observed, especially if the plant’s bulb is still alive. Reapplication intervals with 2, 4-D Amine range from 21 to 30 days. Reapplication intervals with Fahrenheit range from 4 to 6 weeks.

Applications are most effective when plants are actively growing before seed production. If the plants are close to producing seeds, you may need to mow the plant to prevent the weed from spreading.

If you do mow, the bulb will survive and grow a new plant over the next year, providing another opportunity to apply chemical control. Keep in mind that mechanical removal alone is not recommended, as it is easy to leave bulbs in the soil to grow new plants next season.

Prevention

Once you have eliminated wild onion from your lawn, you will need to implement some preventative measures which ensure that this stinky weed doesn't make a comeback.

• One of the best ways to control wild onions after they’ve been eliminated from your property is to mow them down if new plants start to sprout. When mowing lawns, simply mow regularly to the grass’s proper mowing height. Removing weeds before they can reproduce will stop them from spreading onto your property.
• We also recommend promoting the health of your turf to reduce the conducive conditions that allow weeds and disease to take hold. Reduce the shade cast on your lawn by trimming overgrown shrubbery and tree branches, rake away leaf litter and pick up any debris, and employ a proper watering schedule to provide the local grass with enough water to strengthen its roots, but not so much that will encourage weeds. Many grasses require 1 inch of water every week. Apply the water all at once in the morning so it has time to seep into the ground without evaporating in the sun.

Key Takeaways

What is Wild Onion?

• Wild Onion (also called Onion Grass) is a common weed that grows on lawns and flowerbeds and has distinctive onion smell.
• Wild Onion looks similar to wild garlic with the main difference being that wild onion has wider, more grass-like leaves, while wild garlic leaves are thin, tube-like and hollow.

How To Get Rid of Wild Onion In Your Yard

• To treat growing wild onion, we recommend applying 2,4-D Amine Selective Weed Killer. Treat the wild onion in the early fall to November with a follow-up treatment near the end of winter into early spring (February or early March).

Preventing Wild Onion Reinfestation

• Prevent wild onion by monitoring your lawn in the fall and early spring for a few years and reapply 2,4-D periodically if you see young wild onion growing since the weed's bulbs can stay dormant in the soil up to 6 years.