How to Identify Garlic Mustard - Foraging for Wild Edible Greens
Garlic mustard (Alliaria petiolata) gets a bad reputation for its highly invasive qualities, but if all exotic foreign plants were this savory and nutritious, we might look at them a little differently!
So named because it’s a member of the mustard (Brassicaceae) plant family with a flavor reminiscent of garlic, A. petiolata is a common weed throughout Europe and North America that is currently invading new territory every season here in the U.S.
That’s bad news for the woodland spaces that it comes to occupy, because it drowns out native biodiversity by exuding a compound from its roots that inhibits the growth of beneficial soil fungi (mycorrhizae) and prevents seeds from germinating.
Thankfully it’s as delicious as it is destructive, and it’s also one of the most nutritious leafy greens you can possibly eat, beating out kale, spinach, collards, and pretty much any other domesticated crop. So do your part—for your forest and your health—and harvest plenty of garlic mustard anytime you see it! Here’s what you need to know about it.
Where to Find Garlic Mustard
Garlic mustard is most common on forest edges and in shaded woodland areas, but it is also known to grow in open fields. You will often find it on shady roadsides, fences and hedgerows, and along walking paths in the woods. It tends to grow in clusters and patches because its seeds generally fall within a few feet of the parent plant.
How to Identify Garlic Mustard
Garlic mustard is pretty easy to spot for newbies, especially as the growing season progresses and it sends up flower stalks.
It seems that garlic mustard most commonly grows as a biennial, which means that it sprouts and grows vegetation in its first year, then returns from overwintered roots the following spring to produce seeds. The second-year growth tends to be much larger and more conspicuous, and thus easier to identify.
Garlic mustard leaves are quite distinct once you’ve developed an eye for them, but their variation in size and shape can lead to some uncertainty when you’re still learning. They vary from rounded, to kidney-shaped (reniform), to triangular, with a slightly rounded or serrated edge. Leaf venation is very pronounced and the foliage is often a deep and distinct shade of green.
Early in the season (February and March for most of its range) garlic mustard grows as a small, squat herb on the forest floor, but in April or early May it quickly sends up a flower stem (petiole) that can reach as tall as three feet. This stem terminates in a small cluster of tiny white flowers with four petals that should be familiar if you know how to identify other mustards like bittercress or domesticated brassicas. The flower stem eventually elongates into a seedpod stem, featuring many stringy pods reaching up to the sky like stick-figure arms.
There aren’t many plants out there that look anything like garlic mustard, which makes this wild edible plant especially easy to positively identify. The common lawn and garden weed ground ivy (Glechoma hederacea), also known as creeping charlie, has leaves that are superficially similar in appearance, but its tiny violet flowers and a growth habit as a ground-cover vine make it easy to distinguish. Ground ivy is edible, too (though not as tasty), so don’t worry if you slip up here.
When in doubt, pluck a couple leaves and crush them up with your hand – do they smell like garlic? If so, you’ve found what you’re looking for.
When to Look for Garlic Mustard
Overwintered garlic mustard will begin to send up new growth as early as January here in Kentucky (Zone 6), but it’s not until February or March that it starts to become more noticeable on the forest floor. By April and May you’ll be seeing it everywhere as its characteristic flower stems shoot up, and after the seeds have matured in June, the second-year growth will die back.
Just before the overwintered plants go to seed, the next generation of seedlings from last season’s seed will be sprouting in clusters around the more mature plants. So after those older plants complete their life cycle, the first-year growth developing nearby will become more apparent.
Garlic mustard is a pretty hardy plant that can tolerate cool temperatures and may even be present year-round where winters are more mild. In places where hard freezes are more common, garlic mustard will lose its foliage and die back to its roots.
Seeds require cold stratification to germinate, which is a fancy way of saying that they won’t grow until after they’ve been exposed to the prolonged cold of winter.
How to Harvest Garlic Mustard
This one’s easy—rip that sucker right out of the ground! You’ll be doing your local woodlands a favor by helping to control one lean, mean pest that’s doing some serious damage to our native plants and fungi.
(Of course, it’s always a good idea to obtain permission wherever you intend to do this, if possible, so nobody gets upset about your wanton destruction of these plants.)
I’m told that stem tips are good to eat cooked for a short period in the spring before the flower buds open, but your primary focus when harvesting should be on the size and quantity of the leaves.
When you have a choice, always go for the bigger, taller plants with the larger leaves near the base. These will give you more food for less work, and those larger leaves will usually be less bitter than others when the plant has gone to seed. The smaller, more triangular leaves growing higher on the stem will be more bitter.
When cutting or plucking the leaves from the stem, try to keep as little of the stem as possible. It’s especially stringy and fibrous, and not much fun to eat. If you’re not going to use it right away, submerge it in ice-cold water and stick in the fridge. It will keep this way for a few days.
How to Use Garlic Mustard
To my palette, garlic mustard leaves are delicious raw – the flavor reminds me more of roasted garlic, with a hint of bitterness that doesn’t usually bother me. Other people are turned off by the bitter notes, but I think it’s an acquired taste, like beer or fermented vegetables.
Don’t fret if you’re not into the bitterness, because cooking your garlic mustard will neutralize it. I like to coarsely chop it and use it as a substitute for greens like spinach, collards, or chard in dishes like stir-fries and omelets. No garlic cloves necessary!
Diving into the wonderful world of wild foods can be intimidating, especially if you don't have much experience working with plants.
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The book was written with the absolute beginner in mind, and with the goal of getting you out into the world gathering wild foods right away.
Introduction to Foraging goes into much greater detail on chickweed, garlic mustard, bittercress, and field garlic, as well as several other wild plants that are very common and very easy to identify.
To learn everything you need to know to begin foraging safely, sustainably, and confidently, check out my book here. Happy hunting!
By the way...
If you're looking for more help with wild plant identification, and you're wondering how to tie foraging into your local, seasonal diet, why not join us over in the Farm and Forage Challenge group on Facebook? You'll be able to connect with folks just like you and me all over the world who are eating seasonally from the landscapes that surround them. I hope to see you there!