5 Invasive Ground Covers to Avoid

Bishop’s Weed/Goutweed

There’s no denying that the variegated form of bishop’s weed is an attractive plant. It even grows well in shady sites, where you need splotches of white to brighten things up. But this vigorously spreading plant is one of the earliest plants that was identified as invasive. It was first noticed to have escaped cultivation and become invasive in Rhode Island in 1863. Today it is classified as an invasive species across much of the United States.

• Name: Bishop’s weed (Aegopodium podagraria)
• Identification: Creeping, herbaceous perennial reaching 1.5 to 3 feet in height. The white umbel flowers resemble those of Queen Anne’s lace. The variegated leaf color often reverts to solid green outside of cultivation.
• Mode of spreading: Self-seeds and spreads via rhizomes. The roots from a dense mat, smothering out any nearby plants.
• Removal: Cut it down as short as possible in the early spring and then cover the area with black plastic. The lack of photosynthesis and water and the extreme heat will eventually kill the plant.
• Non-invasive alternative: Golden Alexander (Zizia aurea)

Bugleweed

One individual plant of bugleweed looks harmless and charming, but it will spread by runners and quickly form a dense mat. There are places, like hillsides, where mat-forming plants are welcome. They prevent erosion and don’t need mowing or maintenance. But you should not plant bugleweed anywhere near your lawn or garden beds.

• Name: Bugleweed (Ajuga reptans)
• Identification: Grows from ground-hugging rosettes, some varieties have purple or maroon leaves. It has purple flowers in the spring.
• Mode of spreading: Spreads by runners and quickly forms a dense mat. It moves into the lawn and kills the grass.
• Removal: Dig it up deeply and thoroughly and sift through the soil to make sure no roots are left behind as the plant grows back even from small fragments. Alternatively, cover the area with black plastic and leave it on for several months.
• Non-invasive alternative: Barren strawberry (Waldsteinia fragarioides)

Chameleon Plant

Native to southeastern Asia, this plant was sold as a winter-hardy ground cover that grows in a wide zone range (USDA Zones 4-10) and has become the nemesis of gardeners who made the mistake of planting it. The chameleon plant is virtually impossible to get rid of. It is a rapid spreader that covers anything in its path, forming a thick mat of roots that are impossible to thoroughly fish out and remove.

• Name: Chameleon plant (Houttuniya cordata)
• Identification: This creeping plant grows 1 to 2 feet tall with leaves in an eye-catching mix of red, cream, and green. When crushed, the leaves have a fishy odor with citrus and coriander undertones. The small flowers in the spring and summer are green or white.
• Mode of spreading: By fleshy rhizomes, spreading indefinitely and becoming intermingled with other plants.
• Removal: A combination of repeated herbicide applications and smothering it with black plastic for entire seasons can at best contain its spread. Any remaining root will form a new plant and continue spreading.
• Non-invasive alternative: Wild ginger (Asarum canadense)

Evening Primrose

It is rather uncommon for native plants to be problematic but the weediness and aggressive self-sowing habit of the evening primrose make gardeners often wish they had never planted it. Common evening primrose is native to Eastern North America and the showy evening primrose, also called Mexican primrose, is native to the southwestern United States and into Mexico.

The plants are persistent in the garden to the point of becoming invasive due to their prolific reseeding.

• Names: Common evening primrose (Oenothera biennis); showy evening primrose (Oenothera speciosa)
• Identification: Common evening primrose is a biennial with yellow flowers between July and October. In its second year, it sets seed after the bloom and then dies. Showy evening primrose is a perennial with pink to white flowers between May and October. The flowers of evening primrose open at night and close by noon.
• Mode of spreading: Self-seeds.
• Removal: Promptly pull the entire plant after the bloom before it produces seed.
• Non-invasive alternative: Helenium

English Ivy

Ivy has been used so long as an ornament on venerable old buildings that, understandably, people would think it’s benign. However, it damages the buildings and trees it climbs. In areas where it is invasive, such as in the Pacific Northwest, it wipes out any vegetation in its path, including trees and shrubs.

While the odd topiary or trailing vine in a container is fine, use caution if you need to dispose of plants at the end of the season. They will survive in your compost heap. The one place English ivy is safe is when grown as a houseplant in a container.

• Name: English ivy (Hedera helix)
• Identification: Woody vine with evergreen leaves and insignificant greenish flowers in the fall.
• Mode of spreading: Spreads by vines that root at the nodes and climbs over any obstacles. It also spreads from seed when birds eat the fruit.
• Removal: Pull by hand if the plant is small. Killing an ivy infestation requires the application of an herbicide. If ivy is climbing up a tree or attached to a wall, the vines need to be cut to a manageable size first.
• Non-invasive alternative: Virginia creeper (Parthenocissus quinquefolia)