Natural landscaping advocates rejoice when they see homeowners reducing the size of their lawns. This isn’t always good news, though. Back in my conventional landscaping days, I got rid of lawn in places where turf grass didn’t grow well. And what did I plant instead? Groundcovers – the kinds readily available at garden centers and by donations from other gardeners.
Discovering groundcovers
Many years ago when we first moved to our house, I discovered growing here and there a vine with pretty blue flowers. It was periwinkle (Vinca minor), a European native, also called myrtle. I gathered every plant I could find around the yard to fill in a scruffy area in the back. I succeeded. Then I learned that this vine invades natural areas, forming a mat that excludes native plants. I became aware of it growing along roadsides and extending into woodlands.
I recall how pleased I had been to find a whole flat of English ivy (Hedera helix) at the garden center for a good price. I soon had planted the beginnings of a green carpet along my side fence. Long after it had established itself, I learned that this plant, native to parts of Europe, Asia, and Africa, is an invasive species in most of the United States. It’s especially harmful since it not only can form a dense mat that excludes native plants, but can also climb trees, weakening or killing them by blocking light or adding so much weight that they’re susceptible to blowing over in storms. It’s also a reservoir for bacterial leaf scorch that can affect trees such as elms, oaks, and maples. And besides spreading vegetatively, it can spread to new areas by seed, courtesy of birds that eat its berries.
I also had planted Japanese pachysandra (Pachysandra terminalis) under bushes and trees, and in areas where nothing else seemed to grow. Is pachysandra invasive? It does not appear on invasive plant lists as consistently as plants such as periwinkle or English ivy. Some areas, however, such as Virginia and Pennsylvania, do report that pachysandra has appeared in natural areas, crowding out native species.
Completing the sorry history of my groundcovering past are sweet woodruff (Galium odoratum), bugleweed (Ajuga reptans), and dead nettle (Lamium galeobdolon). Groundcovers such as these seem to be in the same category as pachysandra – not currently appearing on official invasive plant lists, but often on watch lists, since they’re suspected of invading nearby natural areas. By dumb luck, I never happened to acquire the invasive goutweed (Aegopodium podagraria), a native of Europe and Asia, also known as bishop’s weed or snow-on-the-mountain. I don’t envy my fellow gardeners as they report their endless battles to eradicate this plant.
What to do? Prioritize.
So here I find myself – a native plant advocate, invasive plant enemy – with a yard free of the obvious invasives like burning bush, but finding the remnants of my past lurking at ground level. What to do? Given the difficulty of removing these plants and the cost of replacing them, I’ve established some priorities. My first priority is to eradicate those plants such as English ivy officially identified as invading natural areas and capable of reaching new areas by seed. I’m close to conquering my ivy by having repeatedly pulled it out, trying to leave no bits behind. (I’ve chosen not to use herbicides, though they would be effective.)
My next priority is to remove plants such as periwinkle, identified as invading nearby natural areas by vegetative means. Though in my urban/suburban area they may pose no immediate danger, they do silently promote their own use every time someone admires their pretty flowers and neat growing habit. (Those fortunate enough to live near natural areas have a greater responsibility to eradicate them.) I want to offer the opportunity for people to see examples of our beautiful native plants, as well as to provide native wildlife with the benefits of plants with which they have evolved.
Though it’s a slow process, I’ve been acquiring native plants such as the native pachysandra (Pachysandra procumbens), also known as Allegheny spurge, with the goal of covering the ground with natives instead.
Convincing people to plant something other than these popular groundcovers won’t be easy. Even as native-plant societies and state departments of natural resources report their invasion into natural areas, most university horticulture departments and cooperative extensions are promoting most of them as fine groundcovers. And all conventional garden centers sell them. In fact, the reasons for their invasive tendencies are the same reasons for their popularity. They’re attractive, easy to grow, and form a mat that excludes other plants, providing that green, uniform look characteristic of the turf grass they’re replacing.
As Wild Ones, we can provide a different example. Instead of planting “groundcovers,” we can instead cover the ground with native plants, either used alone for a conventional uniform look, or better yet, mixed together for diversity and to expand the public’s idea of what a landscape can be.
Examples of Native Plants to Cover the Ground
- Wild ginger (Asarum canadense)
- Ferns such as New York fern (Thelypteris noveboracensis)
- Partridgeberry (Mitchella repens)
- Creeping phlox (Phlox stolonifera)
- Green and gold (Chrysogonum virginianum)
- Foam flower (Tiarella cordifolia)
- Alumroot (Heuchera Americana)
- Penn sedge (Carex pensylvanica)