Anybody who has heard me talk about gardening knows that I have an uneasy relationship with Japanese pachysandra (Pachysandra terminalis) which is easily the Number 1 planted shade groundcover in New England gardens. Oh sure, it spreads quickly to form a solid green mat in the shade under trees, and its evergreen foliage stays green all winter. You can find this plant at every garden club plant sale and divisions of it have been passed from gardener to gardener for at least a generation. There is probably not a single neighborhood in Massachusetts that doesn’t have an acre or two of of what horticulture guru William Cullina calls “the vinyl siding of landscaping” (an expression that makes me giggle every time)…
But this plant has a darker side, through no fault of its own other than the fact that it’s a foreign import into a landscape where it has no natural controls. Unfortunately, when Japanese pachysandra is planted near moist woodlands in New England, it can quickly spread into the woods through its underground roots, choking out anything else that happens to be growing there and threatening unique and fragile woodland plant communities. There are few (if any) native herbivores (insects or other leaf eaters) that can digest the foliage of this alien plant, or co-evolved pests that control its growth in any way. And once Japanese pachysandra is established in an area to its liking, good luck removing it. Ever!
In the photo above, this lush border of pachysandra needs to be rigorously “pushed back” with a sharp spade twice a year, to keep it from becoming an entire backyard of pachysandra….
When we moved onto our small farm six years ago, we were delighted to find a beautiful stream flowing through it, and even more thrilled to discover unique native plants such as trilliums, jack-in-the-pulpit, Christmas and sensitive ferns, and winterberry holly growing in the rich, moist soil along its banks. I did find some Japanese pachysandra also growing along with Japanese barberry (another invasive planted by a previous well-meaning gardener), but I targetted those for removal in hopes of expanding the populations of the native plants. I spent a few hot summer days standing in the cool water of the stream pulling the roots out by hand (it was not a very large area), and thought my work was done.
Fast forward a year or two, when I noticed that not only was the pachysandra still holding on along the streamside, but that it had literally jumped the garden gate, and had spread at least 10′ into the woods:
I began beating back the pachysandra again – trying carefully not to damage tree roots and the now-tattered jack-in-the-pulpits. I do not use the weed killer Roundup (or its cousin Rodeo) because of its negative impacts on amphibians, not to mention the fact that this heavily-used neuro-toxic herbicide is being increasingly linked with fetal cell death in humans, along with other alarming impacts to people and wildlife. So armed with only a small garden fork and my hands, I have opted for hand-to-hand pachysandra combat. This spring, I declared 2011 “The Year I Shall Remove the Pachysandra Regime”, and each day I’ve resolved to pull out pachysandra roots for 15 minutes until the pachysandra is completely GONE. Wish me luck! I hope to report back in a few years on the newly restored native plant populations that should be making a comeback!
Jack-in-the-Pulpit (Arisaema triphyllum) is one of the cool New England bog plants that I’m trying to save from a thickening mat of Japanese pachysandra in our “wet woods” (Photo of jack-in-the-pulpit copyright Trudy Walther)
A note about hand-weeding: Pulling weeds by hand might seem like a lot of work, but its slow and steady pace is great for teaching you about the makeup of your soil and how certain plants impact their surroundings. I’ve noticed that where my pachysandra roots form a tangled mass of stolons (runners), they seem to suck up all the soil moisture from an otherwise boggy area, and the resulting soil becomes dry and lifeless. In my pachysandra monoculture, I find no other plants, no tiny decomposing insects or butterfly caterpillars looking for leaves they can eat, no salamanders or frogs, nothing at all except the thick white pachysandra roots. It’s clear to me that the pachysandra has, in a few short years, impoverished my rich woodland soil, and nearby plants (and their associated wildlife) are all suffering from these rapid changes to their environment.
If you’re also battling pachysandra, please share your control stories from the trenches!