Fight Garlic Mustard with Native Groundcovers
Garlic Mustard (Alliaria petiolata), Buckthorn (Rhamnus cathartica), and Japanese Honeysuckle (Lonicera japonica). If plants could ride horses, these would be the three horsemen of the Invasive Plant Apocalypse – at least for shady areas in the Midwest. However, a recent post in The Native Plant Herald (the blog of Prairie Nursery in Wisconsin) tells us how native woodland groundcovers can be used to keep these botanical barbarians from running amok. To read the post, click here.
To be clear: the plants discussed here are generally native to parts of the eastern and central regions of the US and Canada. In other regions, this information may not apply.
I have experience with some of the plants discussed in the post. Wild Ginger (Asarum canadense), for example. According to Prairie Nursery, Wild Ginger “forms a solid mat of roots at the soil surface … Once established, a bed of Wild Ginger is essentially impervious to invasion by garlic mustard, buckthorn and honeysuckle.”
I can attest to the solid mat of roots. What’s more, Wild Ginger is a darn good-looking groundcover for shady gardens. On the west side of our house, I have a couple of patches of Wild Ginger, in some places interplanted with Lady Fern (Athyrium filix-femina). They seem to live comfortably together. Wild Ginger roots do smell like ginger, but the plant is entirely unrelated to culinary ginger.
Unfortunately, to establish a bed of Wild Ginger you first have to remove the Garlic Mustard.
Another native recommended in this post is Long Beaked Sedge (Carex sprengelii). I planted a patch just last year in our shady back garden and it has already formed a very solid mass.
Long Beaked Sedge has pretty nice seedheads.
There’s a lot of Northern Sea Oats (Chasmanthium latifolium) in our garden. It definitely forms a solid mass, and it’s a really beautiful grass in summer and fall.
However, be careful where you put it, because it is a bear to remove and has definite expansionist tendencies.
There’s one plant mentioned in this post that in my garden has not been much of a weed inhibitor: Big Leaf Aster (Eurybia macrophylla). Or as my kids like to call it, Big Ass Leafter. Not sure if I don’t have the right conditions, or what.
Anyway, this post mentions a couple of other plants and I’d recommend it to anyone who has a shady or woodland garden.
gardeninacity 
Thanks for this good advice, Jason. I can use it!
You’re welcome!
Sounds good advice Jason but some of the recommendations might seem invasive in themselves to some people.
Yes, certainly the Northern Sea Oats can be a problem with how it spreads while being difficult to remove.
Good advice Jason. I think native plants won.
Thanks, Nadezda.
I’m still trying to find a native groundcover that will choke out Bermuda grass, It’s kicking my butt this year! So, if you hear of anything, please let me know.
I certainly will, though I don’t think we have Bermuda grass here. Crabgrass, now, is another story.
I’ve just checked that Northern Sea Oats is available over here and it is – yay. I have the perfect area for it. Thanks Jason 🙂
You’re welcome, Sam! The Sea Oats is a beautiful grass but you have to keep an eye on it.
Sounds like a good strategy for managing unwanted plants. The ferns with wild ginger look nice together.
They do, don’t they?
I can attest to the wild ginger in shady places keeping unwanted visitors at bay! Love those Northern sea oats. They are pretty indoors in a vase too.
That’s true. I keep meaning to cut some sea oats for a vase inside.
The plants may differ from region to region, but the overall advice is genius and (in my experience at least) very true — if you want to block invasive plants or weeds, you only have two options:
1) Get on an endless treadmill of mulching, pulling, hoeing and putting down sprays and pellets of herbicides containing who-knows-what
OR
2) Plant a native (or non-invasive exotic) that’s tougher than the weeds and able to outcompete them.
#2 seems like the clear winner to me.
(Most of the specific plants recommended by Prairie Nursery aren’t native down here in Tennessee and I don’t think would grow well down here. I tried one native ginger and it has survived – barely – but has not thrived and not spread. I also don’t have much shade. But I am trying several different sedges and think I have some that have sprung up naturally too in garden beds. The other day, I watched a male cardinal eating sedge seeds. A beautiful sight!)
I have several different sedges. I’d love to see the cardinals eating the seeds.
An excellent post–it’s always good to discuss the downsides of the “botanical barbarians” (love that, btw!) and promote useful and appropriate native alternatives. Like you, I also enjoy the Inland sea oats– a beautiful native plants and especially for shady spots.
The sea oats is a really tough and beautiful plants. In fact, I think it is probably better to plant this in more challenging spots.
Jason I was thinking the same thing….and it is one of my projects for next year, once I see where and what I need.
Sounds like a great project. Take some pictures and do a post next year.
I am surprised that Ginger isn’t used more often around here. It is so pretty and carefree. I like those sea oats too. Thanks for the info.
The Ginger is definitely a carefree plant. I don’t have to do anything for it.
Your big leaf asters look just like they do when I find them at the edges of woods, but it is true that not much else grows among them. I can’t guess why yours aren’t doing what they normally do.
Your wild ginger looks much fuller with more foliage than the examples I see here.
I was just noticing this afternoon that the Big Leaf Asters seem to have spread quite a bit since last year, so maybe I should just be more patient.
What a coincidence. I heard Robin Wall Kimmerer speak today, she’s the author of Braiding Sweetgrass which I’m reading, and she mentioned garlic mustard. I’ll probably write about the book in my next post. She mentioned “invasive” species and said a tiny bit about balance – how nothing is inherently bad, we just need balance and sometimes we have to consciously cut back a plant and make space for another kind.
I’d really like to read 1493, the sequel to 1491 by Charles Mann. He talks a lot about the introduction of plants to the New World after the arrival of Europeans.
I had wild ginger in my shade gardens in Maine but it never did as well as yours. I think the harsh winters had something to do with that.
I also think Wild Ginger likes more alkaline soils, and yours was probably acidic.
Yes, this seems to work pretty well. I’ve also noticed that Wild Columbine seems to compete well with Garlic Mustard at some of Wisconsin’s state parks. They bloom around the same time, and Wild Columbine is just a smidge taller than the Garlic Mustard.
I never would have guessed that about Wild Columbine. It doesn’t at all seem like an aggressive plant.
Thanks for this info, Jason. I started noticing garlic mustard here just a few years ago. There’s an area under and right in front of a large evergreen that is prone to it and another invasive weed I haven’t identified. I did plant a few wild ginger plants as well as a type of Lamium known as “Golden Archangel.” Both are spreading and seem to be doing the trick in keeping out other intruders. The friend who gave me the Lamium warned me it could spread, but said it was easy to control, though now I see it’s called invasive by many sites. Still, it’s much better than garlic mustard.
The Lamium isn’t nearly as invasive as the Garlic Mustard, which seems to produce seeds by the million.
I’m waiting for my shipment of big ass leafer from Prairie Nursery and hope it does well in my dry shade. 🙂 I have garlic mustard but it’s not as horrible here as it is farther north. I need to find a spot for that ginger. Love it!
I think any of the shadier spots in your back or side garden would do.
The Wild Ginger that I have relocated from a natural woodland have performed much better than nursery grown potted plants, making me wonder if it does better with Mycorrhiza in the soil. Terrific plant and great choices you have suggested!
Thanks! Perhaps the Wild Ginger from the local woods is a locally adapted genotype.
Thanks! Perhaps the Wild Ginger from the local woods is a locally adapted genotype.