Wild Onion Grass & Wild Garlic – Identification and Control
November 3, 2018
Methods to get rid of wild onions and wild garlic in your yard
If you are reading this post then you’ve seen them. Those pesky tall dark-green to white stalks rising above your grass in the Fall and Spring that will dull your lawnmower blade. Well, there are really only a few effective ways to get rid of wild onions (also known as onion grass) and wild garlic that are established,
Dig them out, removing the bulb/roots (organic, most effective, minimal disturbance/damage to your lawn)
Leave them. They don’t actually harm anything, but just look bad.
Ignore them, as they are dormant during most of the growing season
They grow at a fast pace in late fall and Spring while your grass has slowed down. So you will see the isolated green clumps sticking above your lawn. Hence it can be very noticeable and unsightly. I will say this though – as tempting as it is, you should NOT pull them. Unless you have very loamy, black, crumbly soil, you will likely break the stalk, leaving the bulb. This means the plant will come right back and sprout more stalks.
Wild Onion and Wild Garlic – a hundred year old problem!
Back at the turn of the century (19th/20th that is) farmers were advised to plow their fields in the winter to help kill off these bulbs. As the turning of the soil would expose most of the new bulbs to the elements, killing them. If they neglected to do this they risked having their wheat taste bad, resulting in lower prices. Or having their cows milk taste sour, and would be unable to sell it.
Wild Onions versus Wild Garlic – Similarities and Differences
Wild onions/garlic are any Alium species that wasn’t cultivated by you. So, basically any Alium growing in your lawn.
The primary difference between Wild Onion vs. Wild Garlic is the leaves. Wild onion will have many leaves coming from one stalk, while wild garlic will have single, tubular, hollow leaf coming right from the ground.
Since they are of the same genus, they are more similar than different. For example, the most common similarities;
Both grow during cooler temperatures, namely Early Spring and Autumn
Both will grow taller than your grass at this time, since your grass is likely to be slow growing or dormant due to cooler temperatures
Leaves from both will have a strong garlic or onion odor
Both are perennial, meaning they will come back year after year unless you remove/kill them.
Both wild onion and wild garlic will have a very distinct, pungent garlic-y smell when disturbed/cut
Wild Onion has flat, broad leaves all coming up from one stalk. There are numerous different species that could be present in your lawn. Basically one bulb can produce many leaves all coming from the same stalk. Also, the leaves may spread out or hang down, like a very ‘upright’ tall version of crabgrass. If you cut a leaf of wild onion, it will not be hollow.
Wild garlic is native to Europe/Asia/Africa and was introduced as a food source by colonists. This is a perennial bulb that will eventually from into clumps of individual bulbs/stalks. It has spread via seeds/bulbs and is generally present throughout the Eastern United States, into the Midwest and along the West Coast. When people talk about wild onions growing in their lawn, they are most commonly referring to wild garlic. The bulbs are generally 3-6″ below ground. If you cut a leaf of wild garlic – it will be hollow.
Controlling Wild Onion/Garlic – What you should NOT do
Don’t ever pull on the tall stalks of wild garlic. The stalk will almost always break away, leaving the bulb full in-tact in the soil. Nature has engineered this plant to survive losing its stalk/leave! It will just send up more stalks at a later time. Perhaps in a week or two if it is during the Early Spring or Fall. I repeat – don’t pull wild onion/garlic. If you break the stalk, you will most certainly be leaving the bulb behind, and will just have to attack it again at a later date.
Best methods to control Wild Onions/Garlic
Removing the plant/bulb by digging
If you don’t have 300 plants poking up through your grass, then this is the most effective organic way to do remove/kill the plant. Also, it can be more effective than chemical, since the herbicide will often fall right off the stalks or leaves, as they are quite narrow. One very important tip is that you should wait until after a rain to dig out the bulbs, as it is much easier in moist/wet ground. And above all else – you must make sure you get all of the bulbs/roots.
The roots will run deeper than your grass, so you need to make sure you dig about 6″ (15 cm) deep. Doing so will ensure you most likely get underneath the bulbs, and provide the best opportunity for complete removal.
The simplest way to remove the plant is to dig up the entire plant with a shovel/trowel. You must make sure you remove all of the bulbs/stalks – basically everything. Leaving any part behind will likely result in a new plant growing. Just stab the shovel into the ground near the stalks, and dig them up. Make sure you get the entire bulb/root mass.
How to get rid of wild onions withoutdamaging your lawn
I have developed a really good trick for getting rid of the entire plant, without leaving gaping holes in my lawn. As with the shovel method, you should do this when the ground is moist to make life easier. This can be done with a shovel, or a pitch fork. But what I will do is stab the pitch fork or garden spade about 4-6″ away from the clump of stalks, and make sure it penetrates deep into the ground.
Hold it at approximately 30 degrees from vertical, so that the trajectory will put the tip of the shovel/pitchfork beneath the bulbs (about 6″ / 15 cm deep). Then just gently rock it back, while gently pulling on the onion talks at the same time, until you can flip over or feel under the chunk of sod.
Next, look for a clump white stringy roots poking through the dirt. This will be the group of onion/garlic bulbs. Remove some of the dirt until you can get the clump of bulbs inside your fist, then take your other hand and hold the sod, and pull. You are kind of pulling weeds in the reverse direction, in that the stalks are going down relative to the sod. By doing this you will be removing the entire bulb and stalk, without doing much damage to your lawn/yard. Since the bulbs are most likely to be an inch or two (5 cm) deeper than the grass roots, you haven’t done much mechanical damage to the grass, as they will still be intact. As a final step, just put the chunk of sod back where you dug it up, and nobody will even notice that the wild onions were there.
This entire operation is about the same as if you ran an aerator over this small chunk of sod. So, no real damage, and will reduce compaction at the same time. One less weed, and more room for your grass roots – that is what I call a win/win! The video below details the process;
Killing Wild Onions or Wild Garlic with Chemicals
Since neither are ‘broad leaf’ the common weed killers don’t work well on Onion Grass or Wild Garlic. This is the same problem you have may have noticed on controlling Nutsedge. Broad leaf weeds have a lot of surface area that the herbicide can stick. Wild onions, and wild garlic in particular have small surface area, meaning that it is harder to apply a lot of herbicide. In addition to this, they have a slight waxy coating to protect themselves. So, smaller surface area combined with a coating that sheds weed killer means that most weed killers may not be effective. In addition to that – they have a bulb deep in the ground, that can store a lot of energy to help the plant survive a herbicide attack. Thus, you have a trifecta of herbicide resistance, small round leaves, waxy coating, and an energy filled bulb to resist herbicide. So – you can kill it with conventional herbicides that won’t harm your lawn, but it may take a loooong time.
What herbicides easily kill wild onions?
Certain herbicides have been tested in labs to see when is the best time to spray in terms of the plants age. Research found that spraying herbicide when the plant was young, at the 2-leaf stage was the most effective way to damage the plant. The problem with that is you don’t notice the plant at that stage very much! It most likely just blends in with your lawn.
There a couple of herbicides that have been found to be very effective at killing Wild Onion. Paraquat was found to be very effective at killing Wild Onions in the Spring. While Imazaquin was found to be an effective herbicide when applied in the Fall. Imazaquin is available on Amazon in concentrate form. If you have a severe infestation, and don’t mind using chemicals to kill Wild Onions, then that would be your best option. Just apply it in the fall.
When should I spray wild onions and garlic?
Well, if you have a ridiculous infestation, then you should apply your herbicides after mowing, when the center of the stalks have been cut and are exposed. Or, follow the advice above and apply Imazaquin in the Fall. This will raise the probability that enough chemical will enter the plant to kill the bulb.
What conventional chemicals will kill it?
Glysophate (round up) will kill it, and everything else, but may require multiple applications, and benefits from the wild onion plant having been just mowed to expose the interior stalk. Regulare 2-4-D/Cambria herbicides can kill it with enough applications, but you should do it right after mowing.
As stated above, the easiest readily available herbicide to use on Wild Onions is Imazaquin. You can get it on Amazon here.
What other liquid herbicides can kill it?
A large dose of vinegar in the soil can kill wild onions and garlic. Also, if you boil a pot of water and apply it to the plant, this should kill it too – and all the surrounding grass that is exposed to the intense heat.
Is wild onions / garlic edible?
Warning – there is one other look alike weed that is actually deadly. Death Camus looks very similar to wild onion in many ways. However, it doesn’t have that pungent smell that the wild garlic/onions have, and outside of that you need to wait until it blooms to make a positive ID. But fair warning – I take no responsibility for you consuming plants growing in the wild. You do so at your own risk.
But back to the main question – are wild onions or wild garlic edible? Yes. Both are edible, and can be somewhat nutritious in minerals. For instance, you can use the stalks as a substitute for chives, or as a general seasoning. They are each quite similar to scalions. However, remember, both of these plants have very pungent garlic-y or onion-y smells. If the plant doesn’t have a strong smell, don’t eat it (never thought I would type that sentence).
Do Wild Onions or Wild Garlic cause any problems in my lawn?
In a nutshell – no they don’t. They displace grass, and don’t fit in with a uniform lawn, as they will grow taller than your turf during Spring/Fall. But that is it – other than that they cause no harm to your lawn. Although they are much tougher on your lawnmower blade than Fescue or Bermudian grass.
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USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. 3 vols. Charles Scribner’s Sons, New York. Vol. 1: 499.