Invasive Shade-Tolerant Garden Plants in Vermont

Vermont’s lush forests, rolling hills, and shaded landscapes are susceptible to invasive plant species that thrive in low-light environments. These invasive plants can spread quickly, outcompeting native species and disrupting local ecosystems. Understanding these plants and choosing native alternatives is essential for preserving Vermont’s natural beauty and biodiversity.

Lesser Celandine (Ficaria verna)

List of Invasive Shade-Tolerant Garden Plants in Vermont

1. Japanese Barberry (Berberis thunbergii)

• Description: A small, thorny shrub with bright red berries and small, glossy leaves, often planted for its ornamental appeal.

• Impact: Japanese Barberry forms dense thickets in shaded areas, outcompeting native plants and altering soil chemistry, which can negatively affect the surrounding ecosystem.

• Garden Alternative: Winterberry (Ilex verticillata) - A native shrub with vibrant red berries that supports local wildlife and thrives in shaded areas.

2. Garlic Mustard (Alliaria petiolata)

• Description: A biennial herb with heart-shaped leaves and small white flowers that emit a garlic-like odor when crushed.

• Impact: Garlic Mustard spreads rapidly in shaded woodlands, outcompeting native plants and reducing biodiversity.

• Garden Alternative: Wild Ginger (Asarum canadense) - A native ground cover with heart-shaped leaves that thrives in shaded environments and offers similar coverage without being invasive.

3. Japanese Knotweed (Fallopia japonica)

• Description: A robust perennial with large, heart-shaped leaves and clusters of small white flowers. It spreads aggressively, particularly in riparian areas.

• Impact: Japanese Knotweed forms dense stands that outcompete native vegetation, reducing biodiversity and altering habitat conditions in shaded areas.

• Garden Alternative: Joe-Pye Weed (Eutrochium purpureum) - A native perennial that supports pollinators and thrives in similar conditions without becoming invasive.

4. Common Buckthorn (Rhamnus cathartica)

• Description: A deciduous shrub or small tree with dark green leaves and small black berries. Initially introduced as a hedge plant, it has since become invasive.

• Impact: Common Buckthorn invades woodlands and shaded areas, forming dense thickets that prevent native plants from growing.

• Garden Alternative: American Hazelnut (Corylus americana) - A native shrub that provides valuable habitat and food for wildlife, thriving in shaded environments.

5. Norway Maple (Acer platanoides)

• Description: A large deciduous tree with broad, dark green leaves, often planted for its dense shade and fall color.

• Impact: Norway Maple produces dense shade that suppresses native undergrowth, leading to reduced biodiversity in forested and shaded areas.

• Garden Alternative: Sugar Maple (Acer saccharum) - A native tree that provides similar shade while supporting a diverse understory of native plants.

6. Oriental Bittersweet (Celastrus orbiculatus)

• Description: A climbing vine with bright orange berries and glossy green leaves, often used for decorative purposes.

• Impact: Oriental Bittersweet rapidly covers and smothers native trees and shrubs, leading to significant ecological disruption in shaded environments.

• Garden Alternative: American Bittersweet (Celastrus scandens) - A native vine with similar ornamental value but without the invasive characteristics.

7. Multiflora Rose (Rosa multiflora)

• Description: A thorny shrub with clusters of small white flowers and bright red rose hips, often used as a living fence.

• Impact: Multiflora Rose forms dense thickets in shaded areas, outcompeting native plants and reducing habitat quality for wildlife.

• Garden Alternative: Pasture Rose (Rosa carolina) - A native rose with fragrant pink flowers that supports pollinators and thrives in similar conditions.

8. Lesser Celandine (Ficaria verna)

• Description: A low-growing perennial with shiny, heart-shaped leaves and bright yellow flowers, often found in moist, shaded areas.

• Impact: Lesser Celandine forms dense mats that outcompete native spring ephemerals, reducing biodiversity in shaded, moist environments.

• Garden Alternative: Bloodroot (Sanguinaria canadensis) - A native perennial with white flowers that supports early-season pollinators and thrives in similar conditions.

9. Periwinkle (Vinca minor and Vinca major)

• Description: Evergreen ground covers with glossy leaves and blue or purple flowers, commonly used in shaded gardens.

• Impact: Periwinkle spreads aggressively, forming dense mats that overshadow and outcompete native ground covers, reducing biodiversity.

• Garden Alternative: Bunchberry (Cornus canadensis) - A native ground cover with white flowers that supports local wildlife and thrives in shaded environments.

Conclusion

Invasive shade-tolerant plants can significantly impact Vermont’s ecosystems by outcompeting native species and altering local habitats. By selecting native, non-invasive alternatives, gardeners can help maintain ecological balance, support local wildlife, and preserve the natural beauty of Vermont’s landscapes.

For more information and to connect with other gardening enthusiasts, join our Facebook group: Shade Gardening.