7 Surprising Facts About Invasive Plants

Updated: Apr. 23, 2024

From purple loosestrife to kudzu, find facts about invasive plants—and learn why you'll want to eliminate these non-natives from your yard.

What Makes a Plant Invasive?

Dame's Rocket growing wildly in early JuneBarry Winiker/Getty Images
Invasive Dame’s rocket

Invasive plants have two characteristics. First, these plants are nonnative to the ecosystem, and second, they cause or are likely to cause harm to humans, the environment or the economy.

Check your garden—you might have one of these surprising invasive flowers.

Invasive Plant Damage Is Costly

The invasive aquatic plant Elodea is the first freshwater invasive plant known to have appeared in Alaska. It chokes out native vegetation and spreads easily and rapidly, needing only a 2-inch clipping of its stem to take root in a new location. Because it disrupts native vegetation and damages the quality of aquatic environments, experts say it could cost the Alaskan sockeye salmon industry as much as $159 million a year.

Psst—never plant these invasive shrubs (and what to grow instead!)

Don’t Leave Purple Loosestrife!

Purple Loosestrife (lythrum Salicaria)Tom Meaker/Getty Images
Purple loosestrife in bloom

Many invasive plants are known for spreading quickly. The deceptively pretty invasive purple loosestrife can produce more than 2.7 million seeds annually. Native to Europe and Asia, purple loosestrife looks like a lovely flower—but it’s a headache for many gardeners in the United States and Canada. It grows in wetland environments and crowds out native species. Roots can send out 30 to 50 shoots, which creates an interconnected web of plants.

In addition to purple loosestrife, keep an eye out for the worst invasive plants.

Invasive Plants Are Difficult to Remove

Himalayan Blackberry Isolated On White Background, Rubus ArmeniacusDanut Vieru/Getty Images
Himalayan blackberry

Himalayan blackberry is invasive in the Pacific Northwest, forming impenetrable thickets of up to 500 canes per square yard. As with many native plants, it is incredibly difficult to control and eradicate, especially when attempting to pull it out by the roots.

Here’s how to remove invasive plants from your garden for good.

Russian Thistle Spread Across the Southwest

Russian,thistle,flower,at,the,field.EUGENY POPOV/SHUTTERSTOCK
Russian thistle, also known as tumbleweed, is prevalent in much of the southwestern United States.

Better known as tumbleweed, Russian thistle arrived in the U.S. in 1873. Its rapid spread was accidental. Today, it infests approximately 100 million acres, especially in the American Southwest.

Should you get rid of Canada thistle? Find out what the experts say.

Some Invasive Plants Are Harmful to Humans

Lots of invasive plants hurt the environment, but giant hogweed hurts people, too. Its leaves grow up to 5 feet across, and its toxic sap causes severe skin blisters when exposed to sunlight. If you have the misfortune of coming into direct contact with giant hogweed, wash the affected skin with soap and water as soon as possible. Next, make sure to keep the affected area out of direct sunlight for at least 48 hours.

Is a black locust tree invasive?

Kudzu Vine Grows Extremely Fast

KudzuMartha Snider/Getty Images
Invasive kudzu vine

In summer, kudzu vine can grow up to 1 foot every day, reaching lengths of over 100 feet. Some refer to it as “the vine that ate the South” because of its prevalence in the southern United States. Unfortunately, it was once intentionally planted there as a means of controlling erosion.

Next, find out if trumpet vine is an invasive plant.


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