Plants to Grow Old With: The Battle Against Invasive Species

Many gardeners learn the hard way that some "free" plants come with a lifetime commitment. What starts as a generous gift can become a decades-long battle against aggressive spreaders. Here are cautionary tales from the front lines.

Horseradish: The Unstoppable Root

Planted near potatoes as a companion plant, horseradish outlasted the vegetable garden. Decades later, it persists. Any root fragment left behind regenerates. Black plastic for two years only forced it to send runners elsewhere. It's a permanent resident.

Wild Blackberry: Thorns from Hades

A friend's warning went unheeded. Two years of delicious berries came with shredded skin and runners invading vegetable beds and the neighbor's yard. Eradication took four years of cutting and black plastic. Victory was possible—but costly.

Mint: The Barrier Jumper

Three varieties (apple, lemon, peppermint) laughed at four-inch barriers and mulch. Runners hopped over and dove under, colonizing distant beds. Lemon mint self-seeds prolifically. The only safe way to grow mint: in escape-proof containers.

Wild Passion Flower Vine: The Wanderer

Planted by a porch trellis, it soon appeared in shrubs, hedges, and the neighbor's yard—then circled the house. Underground runners make containment nearly impossible.

Honey Locust: The Sneaky Tree

Lovely pink-lavender blooms mask a habit of sending up suckers far from the trunk—in the middle of herb beds, iris patches, and groundcovers.

Lesson Learned

Research before accepting or planting. "Vigorous" or "spreads readily" in catalog descriptions often means invasive. When in doubt, choose clumping, non-running varieties or grow in containers. Some plants truly are companions for life—whether you want them or not.