5 Invasive Plants You Can Eat

The logic of eating wild plants is obvious; the logic of eating invasive wild plants is even more so. Culling aggressive species that threaten native plants, while avoiding the environmental pitfalls of agriculture? Free, local, abundant food? Yes, please.

Invasive plants are non-native species that can thrive in areas beyond their natural range of dispersal. These plants are characteristically adaptable, aggressive and have a high reproductive capacity. Their vigor combined with a lack of natural enemies often leads to outbreak populations that can reach horror-movie proportions.

Millions of acres of once-healthy, productive North American rangelands, forestlands and riparian areas have been overrun by noxious or invasive plants. They destroy wildlife habitat, displace many threatened and endangered species, reduce plant and animal diversity (as weed monocultures overrun other plant species in an area), and disrupt the flight patterns and nesting habitats of waterfowl as well as neotropical migratory birds — to name just a few of the nuisances they create.

So what can we do? Get eating!

1. Purslane (Portulaca oleracea)

• Native range: Old World, probably Southeast Asian in origin
• Invasive range: Throughout North America
• Habitat: Rocky bluffs, barnyards, gardens, sidewalk cracks, disturbed areas; widely found in city lots

Because it's a prolific producer of seeds, common purslane can rapidly take over warm, moist sites. And although it may not be as threatening as some of the other invasive species listed here — more of a pesky (albeit gourmet) weed — it's included because it's a particularly rampant plant that contains loads of omega-3 fatty acids, as well as being a great source of vitamins A and C.

The profuse succulent has thick, round leaves and small, yellow flowers that bloom from midsummer to early fall. It’s kind of crunchy, with a tangy, slightly salty taste.

How to eat:
Texas A&M; University's AgriLife Extension offers several interesting purslane recipes, including pickled purslane, Mexican purslane stuffing and verdolago con huevos. Purslane also works well in a wide range of salads and soups, from this wild purslane salad to this no-cook purslane and cucumber soup.

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2. Japanese knotweed (Polygonum cuspidatum or Fallopia japonica)

• Native range: Japan, China and Korea
• Invasive range: Throughout North America and Europe
• Habitat: Riverbanks and roadsides, agricultural areas

Introduced as an ornamental plant and for erosion control, this aggressive perennial can reach 6 or 7 feet in height and is all too happy to push out native species. It mostly spreads through rhizomes, with shoots so hearty they break through asphalt and can survive underground for years. Many a frustrated gardener has discovered this species to be nearly indestructible.

The pretty leaves are alternate, egg-shaped; stems are hollow. Small white flowers bloom in late summer. The fruit is a single seed within a three-winged calyx.

How to eat:
Japanese knotweed can be eaten raw, but it's typically cooked. And due to some similarities with rhubarb, it works in a variety of desserts — like knotweed muffins, sherbet and pie. If you're feeling more adventurous, the Guardian offers this recipe for Japanese knotweed vodka.

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3. Dandelion (Taraxacum officinale)

• Native range: Eurasia
• Invasive range: Throughout North America
• Habitat: Public and private gardens and lawns, roadsides, sidewalks, degraded meadows, rocky hillsides, forest openings

Some of us (me) may love the earnest dandelion, but many see the plant as an invasive weed that does little more than sully an otherwise perfectly manicured lawn. It’s believed dandelions were first brought to North America by the Pilgrims on the Mayflower for the plant's medicinal uses. A single dandelion produces around 2,000 seeds per season, giving the weed great potential for broad dispersal, and its non-native status means it can displace its native relatives.

It has been shown that dandelions can pose a threat to alpine zones and upper forests through competition with conifer seedlings. On the other hand, dandelions easily colonize disturbed and over-grazed habitats, and can serve as an important source of grazing for cattle, wild ungulates and bears.

The pervasive root systems of dandelions make eliminating them very tricky without thorough and repeated applications of cultural, mechanical or chemical control, making them a bane to gardeners (and a boon to eaters).

How to eat:
All parts of a dandelion plant are edible, either raw or cooked. The greens are well-suited to a salad, a stir fry or a soup, among many other options. The flowers can be eaten raw, fried or used to make dandelion wine, while the roots provide an even wider range of possibilities. A few recipes worth trying include dandelion pesto, roasted dandelion-root ice cream and cream of dandelion soup.

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4. Kudzu (Pueraria montana)

• Native range: Asia
• Invasive range: Most of the Southeast, and as far north as North Dakota
• Habitat: Roadways, edges of forests, home gardens; everywhere

It has been said you can actually watch kudzu grow — and given that it grows up to a foot a day in the proper conditions, that might just be true. Kudzu was first brought to the U.S. from Japan for the 1876 Centennial Exposition in Philadelphia. By 1900, its fragrant purple flowers and the vine’s miraculously quick coverage ability made it a popular choice for porches across the U.S. Southeast. Now, however, it covers more than 7 million acres across the region.

The insatiable vine will take over anything in its way — other plants, buildings, road signs, you name it. It kills other plants by blocking light, strangles stems and tree trunks, breaks branches, and uproots trees and shrubs. Eat, eat, eat!

How to eat:
Kudzu seeds and seed pods aren't edible, but the leaves, roots, flowers and vine tips are. (Like any foraged food, though. This site lists a range of recipes like kudzu blossom jelly, rolled kudzu leaves, deep-fried kudzu leaves and kudzu quiche.

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5. Curly dock (Rumex crispus)

• Native range: Europe and North Africa
• Invasive range: All 50 states
• Habitat: Common in fields, roadways, gardens, yards, disturbed areas, glades, meadows, and along streams and riverbanks

Curly dock is a highly aggressive plant that spreads by seeds through self-pollination — the non-native plant is found in agricultural landscapes throughout the U.S. and is listed as invasive in 15 states. Curly dock grows very large at times and can block sunlight from other plants in the surrounding area. It can also outcompete its neighbors for soil nutrients and water.

Curly dock is a relative of rhubarb in the buckwheat family, and is also known as sour or yellow dock. It's high in oxalic acid, and may be irritating to sensitive skin, so should only be used raw in moderation. Use it when the leaves are young; the foliage can be boiled in several changes of water. That said, it's delicious.

How to eat:
Wild Food Girl suggests a few recipes across curly dock's wide culinary range, from dock cream cheese spread to stuffed dock leaves to potato, dock and tahini soup.

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For more information and guidance in telling what's what, try a site called Eat the Invaders. And for general foraging tips, check out this guide to summer foraging from the Ecologist.