10 Invasive Plants to Avoid in Your Garden

A tall, purple-flowering butterfly magnet, it’s understandable why gardeners have made this exotic shrub so popular. In recent decades, however, this Chinese species has jumped the garden fence and is aggressively colonizing natural habitats in the west, outcompeting the region’s native plants.

A gorgeous harbinger of summer across Europe, this biennial self-seeds prolifically, especially in wet soils. Invasive-species managers are now actively discouraging gardeners from spreading this weedy species further, as it has been spotted naturalizing across the country.

Brought to the Pacific Northwest by a Scotsman who missed his native flora, this attractive yellow-flowering shrub is now wreaking havoc across hillsides from New York to Oregon. Aggressive and fast-growing, Scotch broom quickly elbows aside other native plants, depleting biodiversity.

One of the most popular evergreen climbers in the horticultural trade, English ivy forms dense carpets in both the canopy and on the forest floor once it escapes the garden’s perimeter. The native groundcover known as Allegheny spurge is an excellent alternative to this invasive vine.

Bright and breezy and easy to grow, it’s no wonder garden loosestrife is a die-hard favorite amongst gardeners. This beloved Eurasian perennial is unfortunately more than happy to grow in places it isn’t deliberately planted, particularly in wet habitats like marshlands and along streams.

There are a multitude of bamboos on the market and most are bullish, aggressive, and downright difficult to control. Prized for their ability to create dense thickets for privacy screens, it’s precisely this characteristic that makes bamboo so hard to control once it escapes the garden and invades wildlands—which it frequently does.

Another native of the British Isles, this beautiful, glossy-leafed evergreen is dispersed by birds and can pop up and cause problems in even the most pristine forest habitats. Instead of planting this interloper, try the native Pacific waxmyrtle, which sports red berries beloved by birds, too.

The iconic tufts of pamapas grass have come to symbolize the Pacific Coast—despite the fact that this species is native to South America, not its neighbor to the North. Not only does this grass form dense stands, making recreation along invaded trails difficult, but the species poses a significant fire hazard, too.

Originally used in windbreaks and as a hedge plant, this silvery-leafed Eurasian native is now a widespread problem across the continental United States. Birds disperse the abundant seeds, making it hard to predict where new populations will become established.

Giant reed’s enormous stature and hardy nature make it a striking addition to any landscape—even where it hasn’t been invited. Capable of invading wetlands and riparian areas, this huge grass can alter a waterway’s natural hydrology and nutrient cycling, and displace native species as a result.