When I moved into my home many years ago, there were very few plants in the yard — a rhododendron, a few random daffodils, English ivy, ferns and a beautiful purple-blooming perennial, which I loved. Just outside the fence that first summer, it grew to 5 feet tall and put forth striking foot-long flower stalks.
I intentionally kept the rhododendron and daffodils, and removed everything else (although I’m still battling the ivy, 15 years later). But I still mourn that purple beauty, whose eviction was necessitated by a lease violation: That gorgeous purple loosestrife not only threatened to disrupt other tenants, it was deemed outright illegal by the New York State Department of Environmental Conservation.
Invasive species, even those confined to your property, can harm the greater ecosystem when their seeds are spread great distances by wind or birds. Those seeds grow where they land, outcompeting native plants because they aren't the chosen food source for native wildlife that would otherwise keep them in check. This gives them an unfair advantage, and by choking out native plants, those birds and animals lose not only their food source, but nesting materials and shelter. No bird, mammal or fish depends on purple loosestrife, according to the DEC, and its seeds germinate faster than many natives.
The DEC has prohibited the sale and use of plants that “cause or are likely to cause economic or environmental harm or harm to human health” (view the full list at on.ny.gov/2VwHa7j). Still, many of these plants and their seeds remain available for sale in catalogs and some garden centers, so it’s important for gardeners to do their own homework.
It’s important to note that not all nonnative plants are invasive, and, conversely, some native plants can be quite aggressive, despite being well-suited to our environment. Elsewhere, some of our natives don’t mind their manners. Our beloved goldenrod, for instance, which spreads vigorously, yes, but nurtures dozens of insect species in our own gardens, is wreaking havoc in Europe, where it is outcompeting some native plant species and has been linked to a decline in the native ant and butterfly populations there.
To save yourself from battling invasives in your garden (which oftentimes means remaining on the right side of the law), it’s best to avoid plants advertised as “fast-spreading,” “quick climbing,” “rapid self-sowers,” “vigorous” or “aggressive” — all marketing code words for “invasive.” It may be tempting to seek immediate gratification from these plants, but you’ll soon learn that when you buy now, you most certainly will pay later.
Here are seven common things to avoid alongside well-behaved alternatives to plant instead.
1. Invasive: Purple loosestrife (Lythrum salicaria)
Alternative: Gayfeather aka blazing stars (Liatris spicata)
2. Invasive: Rose of Sharon (Hibiscus syriacus)
Alternative: Oakleaf hydrangea (Hydrangea quercifolia)
3. Invasive: Golden Bamboo (Phyllostachys aurea)
Alternative: Clumping bamboo (Fargesia spp.)*
4. Invasive: English ivy (Hedera helix)
Alternative: Allegheny spurge (Pachysandra procumbens)**
5. Invasive: Japanese honeysuckle (Lonicera japonica)
Alternative: Trumpet honeysuckle (Lonicera sempervirens)
6. Invasive: Maiden grass (Miscanthus)
Alternative: Switchgrass (Panicum virgatum)
7. Invasive: Dame’s rocket (Hesperis matronalis)
Alternative: Carolina phlox (Phlox Carolina)
**Note this is not the more common Pachysandra terminalis (Japanese spurge) groundcover, which is considered invasive.