If you’re looking to make use of local wild greens, why not give tumble mustard (Sisymbrium altissimum) a try? Tumble mustard—a non-native species from the Middle East thought to have been introduced to North America years ago via contaminated crop seed—is found throughout much of the world, including the continental U.S. and Canada. It can be quite common on deteriorated Western range lands.
You probably know tumble mustard best as one of a group of plants called “tumbleweeds” that detach from their dry stalks at maturity and tumble across the plains on the wind. To make use of fresh tumble mustard greens, however, you need to identify the plant while it is young and lush.
Tumble mustard, like other mustards, produces a basal rosette of greens. When it lays prostrate on the ground it looks like a fantastic jaggedy pinwheel. The pinnately lobed leaves vary in form, with the lower leaves bearing larger, deep lobes that range from smooth-margined near the tip to toothy near the base. Upper leaves are deeply dissected, but bear thin, spindly lobes, giving them a wispy appearance.
When tumble mustard begins to bolt, and the leaves rise up off the ground, they can be lush and lovely for a spell—perfect for a salad. They are somewhat fuzzy in texture, so I like to chop them up and mix them with other greens.
Shortly thereafter, when flower buds form atop the bolted plant inside a burst of spindly leaves, you can clip the whole top off and blanch or boil it in water to use as a cooked vegetable. Or you can chop this part up too and throw it raw into a salad. The flavor ranges from mild to spicy with a mustardy kick. The thin leaves surrounding the mustard heads are of a fine consistency, as are the tender top portions of the stem. Break the stem above where it toughens up, which you can figure out by simply bending the stalk—the same method recommended to asparagus-pickers.
Foraging author Samuel Thayer explains that the meristem, or fastest growing portion of a plant, is the part of a plant you want to eat (Nature’s Garden, 2010). That is when and where the vegetable is at its best for flavor, calories, and texture.
I was surprised to read that tumble mustard has a low edibility rating at Plants for a Future, one of my favorite online resources for wild edibility citations. My guess is that those who rated this plant may not have been eating the tender, tasty, meristemic growth, but perhaps attempting to eat tumble mustard in a less ideal stage.
I recently collected some nice tumble mustard greens in both Manitou Springs, Colorado and north Denver, so the season is on for foragers in those and comparable regions. We even get tumble mustard up here at 10,000 feet in Fairplay where I live, though the season comes a bit later.
Safe practice dictates that if you are unfamiliar with tumble mustard or plants in general and uncertain of your identification, don’t eat it the first time you identify it. Run it by an expert, or wait and watch the plant through a season. If your tentative ID is correct, the mustard will branch many times as it grows, beginning to assume the round-ish form that as a mature plant will eventually break off and tumble on the wind. It will produce small, lemony-yellow, four-petaled flowers. The fruit/seedpods are long and skinny and protrude in a raceme from the stems.
Not too many people write of tumble mustard edibility, but it is indeed edible and in my opinion not bad eating—just so long as you catch the season right and gather it in a good stage of growth.
Sometimes we foragers get zany for a particular wild food treasure—morel mushrooms or wild leeks, for example. But let us not forget that there are humbler finds to be had, green staples growing in abundance that we can easily incorporate into our seasonal fare. In the case of common non-native species like tumble mustard, there’s the added bonus that we might even be helping native ecology by eating them.
- Toxic Lookalike: This is a bit of a stretch, but for folks who are new to foraging, you DO NOT want to confuse tumble mustard or any other edible plant with poison hemlock (Conium maculatum). Poison hemlock is common in Colorado’s lowlands and many other regions, and eating it can be deadly. The greens of poison hemlock, like tumble mustard, are split into many lobes. But they are much more finely and multiple times dissected, and much brighter green. Poison hemlock grows to be very tall, often towering over my head, so even in spring when young hemlock greens are low to the ground there are often tall, dried stalks overhead that help with identification. Novice foragers may mistake poison hemlock for some sort of wild carrot due to the similar leaves. Do not make this mistake.
UPDATE 12.6.17: In this post I originally included a caution that tumblemustard absorbs heavy metals and radioactive waste, based on Howard (2003). However I have since read the paper by Warren (2001) upon which that assertion was made. In his study, tumblemustards that had blown into radioactive ponds were studied to see how much they absorbed radionuclides. That is not the same as a hyperaccumulator that concentrates metals via root absorption, for which I have yet to find evidence on tumblemustard. Thus the caution should instead read as such: If you are going to harvest seeds from dry tumblemustards, don’t get your tumblemustards downwind from radioactive ponds in case they were previously soaking in them.