Your family can fight invasive species—by eating them

Matthew Bruckner and his two kids spent a Maine vacation eating wild blueberries straight from the bush. Returning home, they wondered what else they might forage. Soon the Washington, D.C., family found wild blackberries in the alley behind their house, in dirt patches around the city, and in a nearby natural urban woodland.

It turns out the foraging wasn’t just family fun—it was helping rid the neighborhood of an invasive species.

Invasive species are plants, animals, and other organisms that aren’t native to an area and are harming the ecosystem. These invaders often don’t have animals that eat them in their new environment, allowing them to outcompete native organisms or alter the habitat.

According to research recently published in Science of the Total Environment, invasive plants and animals cause an estimated $21 billion in damage each year in the United States, mostly due to the harm they cause to crops. And according to the National Wildlife Federation, 42 percent of threatened or endangered species are at risk because of an invasive species.

One way people are fighting back against these non-native threats? By eating them. “It’s about getting people outside in nature to learn about the history of the area and the potential damage that invasive species can cause,” says conservation biologist Joe Roman, who runs Eat the Invaders.

Foraging for invasive plants with your family can get kids outside and teach them about protecting the planet. Here are four invasive species to look for—and how you can convince kids to eat them.

Invasive species: Himalayan blackberries

Why they’re bad news: Brought to California in the 1880s by a botanist trying to create new varieties of fruits and veggies, the Himalayan blackberry quickly spread as birds and other animals ate the fruit and dropped the seeds. Native to Armenia, their thorny thickets smother grasses and other plants, block access through the woods for humans and wildlife, and injure livestock.

Where to find them: These bushes grow in early summer along the edges of forests and farm fields and in urban backyards and parks. They’re widespread in the Pacific Northwest and California but are also invasive in some areas of the Southwest, Midwest, and East Coast.

Getting kids to eat them: Blackberries shouldn’t be too hard, but these invasives aren’t as sweet as cultivated blackberries. So they’re best in baked goods like muffins. Beat ⅔ cup sugar, ½ cup Greek yogurt, ⅓ cup vegetable oil, 1 egg, and 1 teaspoon vanilla extract until fully combined. Then mix 1 cup flour, ½ teaspoon baking powder, ½ teaspoon salt, and ¼ teaspoon baking soda in a bowl. Combine wet and dry ingredients and then fold in 1 cup rinsed Himalayan blackberries. Put the batter into a muffin tin and bake at 350°F for 25 minutes.

Invasive species: sow thistle

Why it’s bad news: Sow thistle looks a lot like the also-edible dandelion, but it’s much more destructive. (Dandelions are non-native but not considered invasive.) Its creeping roots crowd out useful crops and suck the soil of water and nitrogen. Native to Europe and western Asia, sow thistle probably arrived as seeds that were accidentally mixed with farm seeds brought over on purpose.

Where to find it: In spring and summer, sow thistle grows in forests, meadows, and riverbanks all over North America. Pull them up by the roots and throw the parts of the plants you don’t use in the trash (not the compost, where it might spread) to keep them from growing back.

Getting kids to eat it: Try sow thistle in a cheesy quesadilla. Sauté 1 cup rinsed sow thistle leaves in 1 teaspoon of olive oil, then set aside. Place a flour tortilla in a pan, spread 1 cup shredded cheese over the tortilla, then add the greens. Heat until the cheese is melted and the tortilla begins to brown, then fold it on top of itself.

Invasive species: kudzu

Why it’s bad news: This vine was brought to the United States from Japan in 1876 to help control erosion. But kudzu can grow up to a foot a day, overshadowing grass, shrubs, seedlings, and even mature trees. That deprives these plants of the light they need to photosynthesize.

Where to find it: The vine’s fragrant purple flowers grow from July to September, but its leaves, roots, and vine tips are available all year. It sprouts in forests from Texas to Massachusetts, as well as in Oregon and Washington. Avoid harvesting from the side of a highway or in manicured areas like golf courses, where herbicides might be used.

Getting kids to eat it: Foraging is hard work—quench kids’ thirst with some kudzu lemonade. Combine 1½ cups sugar and 8 cups water in a pot and bring to a simmer. When the sugar fully dissolves, remove mixture from heat and add 4 cups rinsed kudzu flowers. Let it steep for an hour at room temperature, then strain the liquid to remove the flowers. Add 1 cup lemon juice and serve this pink drink over ice. (You can also boil the leaves and eat them like spinach.)

Invasive species: watercress

Why it’s bad news: Native to Europe, settlers introduced this plant for food. But it soon spread along the edges of waterways and even on the water’s surface, blocking out native plants.

Where to find it: Common along rivers, creeks, and other areas with cold-flowing water, watercress grows in almost all 50 states and Puerto Rico. Harvest it in spring and fall from the water’s edge of a running stream; make sure to rinse thoroughly. (Before foraging, familiarize yourself with water hemlock. It doesn’t look like watercress, but it’s poisonous and sometimes grows in similar areas.)

Getting kids to eat it: Turn the species invasion into a British invasion with some proper watercress sandwiches. Slather white sandwich bread with butter, mayonnaise, or cream cheese, then top with watercress, salt, and pepper. Cut off the crusts for a tea-party look.