In New York, and the Hudson Valley, there are dozens of harmful invasive plants that are simply illegal to sell. These plants are identified as harmful because they out-compete native plants, hurt biodiversity, and harm ecosystems. In some cases, they can hurt people, pets, our food supply, landscaping, parks and waterways. They do the opposite of woodland restoration.
In 2015, New York added a middle group for some species, which were identified as “regulated and prohibited.” A regulation became effective that says that species like Norway Maple, Japanese Virgin’s Bower, Burning Bush, Winter Creeper, Chinese Silver Grass, and Black Locust must be labeled with a warning to buyers that they are harmful to the environment.
In this blog post, we’re going to explain why these six species are labeled as harmful, and also tell you about a couple of native alternatives that you can plant instead.
1. Instead of Norway Maple (Acer platanoides) → Sugar Maple (Acer saccharum)
The Norway Maple is an aggressive invasive tree that has established itself extensively across the Northeast. It is known for its dense canopy, which has a longer growing season compared to native trees like the Sugar Maple. The prolonged shade may inhibit the growth of nearby native trees and shrubs, ensuring that only other Norway Maples grow beneath it. It also has a very competitive root network, and may release toxic chemicals into the soil. If that’s not enough, it’s a preferred host of the Asian longhorn beetle, which is ravaging forests.
If you want a maple tree on your property, the Sugar Maple is a great alternative. It’s ecologically vital to the Northeast, supporting over 280 species of butterflies and moths. It provides food for birds and insects, whereas the Norway Maple only supports a handful of insect species.
2. Instead of Japanese Virgin’s Bower (Clematis terniflora) → Climbing Hydrangea (Hydrangea anomala subsp. petiolaris)
Japanese Virgin’s Bower is an ornamental vine that grows aggressively, forming dense, tangled masses that reach up to 30 feet in height and width. It will easily block sunlight from plants underneath.
It is deceptively similar to the native Virgin’s Bower, and sometimes it’s sold interchangeably at less discerning nurseries. However, the key distinction is that Japanese Virgin’s Bower leaves are smooth and entire, while the native species are toothed and lobed.
However, even the native Virgin’s Bower can still be aggressive. A safer choice is Climbing Hydrangea, which is well-behaved and great for walls, fences, and trees.
3. Instead of Burning Bush (Euonymus alatus) → Chokeberry (Aronia arbutifolia or melanocarpa), Fothergilla, or Viburnum
Burning Bush is a popular decorative shrub, but it’s very difficult to control due to its dense thickets that crowd out native vegetation. It’s capable of self-fertilizing, creating entire colonies on its own, and it lacks natural predators in North America, so there’s nothing holding it back. Another challenge with Burning Bush: when birds eat its berries, they spread the seeds into nearby forests, helping it invade natural habitats.
Alternative shrubs such as Chokeberry, Fothergilla or Viburnum provide superior alternatives that offer great visual interest and lots of ecological benefits. Chokeberry is a low-maintenance shrub known for spring flowers and fall foliage, while providing berries for birds. Fothergilla features beautiful flowers that are great for pollinators. Viburnums are also known for beautiful flowers and berries for native birds.
4. Instead of Wintercreeper (Euonymus fortunei) → Bearberry (Arctostaphylos uva-ursi), Allegheny Spurge (Pachysandra procumbens), or Sweetfern (Comptonia peregrina)
Wintercreeper is an evergreen perennial vine that poses a significant ecological threat. It grows on two fronts, with a dense groundcover, smothering native plants, and as an aggressive climbing vine, which clings to barks with aerial roots. When there are wildfires in forests, wintercreeper is known to be an aggressive “first-mover” that comes into disturbed areas and doesn’t go away.
Instead of Wintercreeper, try Bearberry, Allegheny Spurge or Sweetfern. Bearberry is a hardy dwarf shrub that forms a low-maintenance mat. It’s great as a “living mulch” to prevent erosion and weeds. Allgheny Spurge is a slow-spreading groundcover that thrives in shady areas, which is great for underplanting in gardens under trees and shrubs. Sweetferm is another slow-spreading shrub that is valued for its adaptability in poor soils and its ability for erosion control.
5. Instead of Chinese Silver Grass (Miscanthus sinensis) → Switchgrass (Panicum virgatum), Big Bluestem (Andropogon gerardii), or Bottlebrush Grass (Elymus hystrix)
Chinese Silver Grass is sometimes used by landscapers because of its elegance. However, it spreads aggressively in dense clumps, and can prevent other species from establishing. It’s also highly flammable.
Instead, try Switchgrass, Big Bluestem or Bottlebrush Grass. They all are warm-season grasses that are adapted to local conditions, known for stabilizing soil, preventing erosion and being highly tolerant of drought and floods. They are also host plants for caterpillars and butterflies.
6. Instead of Black Locust (Robinia pseudoacacia) → Honeylocust (Gleditsia triacanthos var. inermis), Hickories (Carya spp.)
Black Locust is an aggressive species that can colonize disturbed habitats and push out at-risk species. It’s a native of the Appalachian region, but it’s becoming invasive in other areas. A key to its spread is the fact that its roots actually change nitrogen levels in surrounding soil, creating an ideal habitat for itself and weeds.
Some alternatives include Honeylocust or Hickories. Honeylocust grows quickly and is resistant to pollution, drought and salt, making it an ideal choice for urban environments. It also changes nitrogen levels nearby, but in a beneficial way. Hickories, like Shagbark Hickory, are a rich food source for wildlife.
