fighting weeds: mugwort and prunella

mugwort and prunellaIF I PRACTICED CHINESE MEDICINE, I’d be all set with enough mugwort (Artemisia vulgaris) and self-heal (Prunella vulgaris) to stock an herbal pharmacy. Whatever their positive properties, though, I see these two ambitious perennials as weeds, and need to tackle them.

My first step with any weed—meaning: wrong plant, wrong place—is to I.D. it, as I have said before, and try to understand its life cycle, so I have a shot at approaching it in the most effective way, and at the right time of year. (More on how to do that, and a link to weed I.D. tools, is at the bottom of the page.) I know I have my work cut out—and probably won’t do better than reducing them, with complete elimination unlikely.

mugwort artemisia vulgarismugwort (artemisia vulgaris)

THE NURSERY INDUSTRY agrees with me on this one: bad news. In the Eastern U.S. and Canada, it’s a major issue, because mugwort’s energetic rhizomes can quickly overtake places where regular cultivation isn’t called for, such as a row of trees or perennials in the field, and the plant can reach 4 to 6 feet tall each season, swamping the desired crop.

lower leaves mugwortEasy to confuse when it first emerges with chrysanthemum, with other Artemisia, and even maybe with ragweed, Ambrosia artemisifolia, one way to tell you’ve got mugwort is its leaves, which are bright green on top, but silvery on their undersides. There’s another foliar clue, which is that the lower ones (just above) are less finely cut than the ones at the top of the plant (as in all the other photos). Again, whether top or bottom leaves, they’ll be green on the upper surface and silver underneath.

mugwort in grassesDespite its use in moxibustion (when an acupuncturist applies heat from the burning leaves to a point on the body), in Ayurvedic medicine, and even (sparingly) to flavor food in parts of Europe and Asia (and in the past to flavor beer), I’d like mine gone. It has insinuated itself in a big island of perennial ornamental grasses (above), where I cannot easily cultivate repeatedly to try to break up the rhizomes and expose them to the surface, where they’d hopefully dry out. I’m left to pull and dig rhizomes after a good soaking rain or watering, to try to at least set it back.

prunella vulgarisself-heal (prunella vulgaris)

THIS LITTLE MINT RELATIVE, an enthusiastic type, loves the rougher areas of turfgrass here, and especially shaded, moist ones. When exposed to regular mowing, it adapts to stay just low enough to escape much damage from the blades, staying quite compact, so mowing isn’t a tactic for fighting it.

I could make a lot of tea from my bountiful supply, and self-heal has been used through the ages as a remedy for immune and skin issues, hypertension and more. And at least it’s green, and low–and bees and butterflies love its little purple flowers, which develop in early summer, though of course that means late-summer seeds, and more Prunella. Prunella vulgaris or some but not all of its sub-species are native in various places throughout the U.S., so no surprise I suppose that it’s popular with the insects. And truth be told: I not positive which sub-species mine is, though I believe it’s P. vulgaris ssp. vulgaris, of Eurasian origin.

I have plenty to make loads of insects happy, but in a few very prominent spots I’m planning on a little Prunella reduction campaign mid-August into mid-September, timed to coincide with the best window for lawn re-seeding here, when I will hoe some of the biggest patches out and sow turfgrasses and clover. Thankfully, self-heal’s roots are not as formidable as mugwort’s.

Clearweedm or Pilea pumilawhy i learn to i.d. my weeds

I KNOW, you’re probably thinking: Doesn’t she have anything to do with herself but figure out the names of her weeds? (That’s clearweed, or Pilea pumila, above, a native, and Galinsoga ciliata, below.) There I go again, but it really does help. The links below the photo might help, too.

Galinsoga ciliata, or Galinsoga quadriradiata, a weed

CategoriesFeatured weeds
  1. Bill Plummer says:

    Panicled hawkweed and white avens are two of my native weeds. The hawkweed, especially is easyto pull up especially when the soil is damp. Among the non-natives areCorydalis lutea and C. ochreleuca, both of which are easy to pull.

  2. Liane says:

    Whew! It was a relief to see that all my Prunellas — which I adore — are not vulgaris. That would explain their well-mannered behavior and my attachment to them. Grandiflora and lanciniata are prolific bloomers and very garden worthy. Bees love them too, but there are — fortunately — less to love! Garlic mustard — which blooms at one inch high — remains my (current) worst thug.

  3. Jill Trachte says:

    I have a question for you :). I volunteer at REGI, (Raptur Educational Group, Inc) so we don’t use any pesticides on any of the invasive we have which include burdock, tansy, and buckthorn. All which can be dealt with with a shovel. But I’m not sure how to deal with the wild parsnip. Any suggestions?

    1. margaret says:

      Hi, Jill. It’s tricky because of the chemicals in the sap that can cause skin issues — you must really suit up and follow protocols to work it carefully — and also b/c it seeds so prolifically. I noticed that a Powerpoint presentation by an invasive plant org in Ontario that’s posted online has a lot of tactical detail and also detailed warning about safety (click here, look at slides 18 onward). Again: key is not to let it seed so even deadheading or mowing down before flowering is well underway and seeds are forming is essential at the least — but must be done w/caution re: your exposure.

  4. Chris Wells says:

    I will gladly trade you horehound (marrubium valgare) and wire grass (wild Bermuda) for your mugwort and prunella! They look like such lovely plants!
    If horehound candy comes back into vogue, I have a cash crop!

  5. Susan says:

    ajuga is my bane ~ a friend gifted it to me when I was younger and didn’t know any better. It’s everywhere on my property. and throughout my lawn. Good news, parasitics and bees are not my problem.

  6. Sharon says:

    In my botanical fantasy life I imagine a common medicinal use for mugwort, the world would be healed,
    there is so much of it.

  7. alan Gorkin says:

    Does anyone have a suggestion for Ground Ivy (Creeping Charlie)– I don’t know the latin name, sorry. I believe it is Glechoma. It grows vigorously in our Vinca.

  8. Arcavius says:

    I’m not sure why mugwort is considered such a problem. One does not have to be a ‘Japanese herbalist’ to use it as food or a medicinal; processing it is easier than making a hamburger! Frankly, the move away from foraging wild herbs and edibles is disturbing, especially since most people don’t even realize why they see such things overwhelmingly as weeds.

    “Weeds” mostly get their bad reputation from big industries engaging in smear campaigns against widely available, wild-grown resources which they believe is hurting their bottom line. These industries can be grain producers, wine makers, and, most prominently, big pharma. That last one is the biggest culprit, taking away free or cheap medicinal sources from the common people who have been fed disinformation for many decades.

    City dwellers can be forgiven to some extent for their complicity in this downplay of wild herbs, since most don’t usually come in contact with plants that aren’t ornamental, ‘lawns’ or obvious fruits and vegetables they get from a store. More distressing are the farmers and rural folk who are either directly involved with growing plants, or are exposed frequently to wild plants and herbs in their environments. These are the folks who should recognize not only the usefulness, but the necessity of natural plants that can provide food, natural protection against pests, and powerful medicine for all manner of problems.

    Given the current state of world economics and climate change, maybe it is time to rethink the real efficiency of strictly cultivated foods. Maybe it is time to consider the things that grow uninvited in our precious flower beds and between the cracks of our driveways and give them a second chance to help feed us. It’s time to break the stranglehold big business has over our food supply and move back to knowing *exactly* what we’re putting on our tables and in our bodies.

    1. margaret says:

      With highly invasive non-native perennials like this that spread extensively and are difficult to eradicate, the issue is not whether they have a culinary or medicinal use but what other plants, native ones, they have extirpated with their increasing presence. A little would be good; miles of it means miles of former botanical residents gone missing, and therefore the food web dependent on those former inhabitants also finding themselves empty-handed.

  9. molly Quigley says:

    what truely brings me to tears, is the lesser celandine! i have seriously thought about moving! does anyone out there have a way to get rid of this beast?

    1. margaret says:

      It’s one of the worst. In a small infestation, repeated hand digging (getting all the plants parts — not just foliage but the bulblets and tubers, too) over several seasons may do the trick, but of course larger infestations are harder and chemicals are often resorted to. With those the timing (earliest spring pre-flowering) is key, and experts warn that they may control but not eliminate the infestation — meaning back to hand digging. No good answer here, except to say untackled it will just get bigger and bigger.

  10. Florence says:

    Oh, Margaret… your article is so timely for me. I’m battling mug wart, again. This thug came into my garden with some iris and before I knew what it was, had transplanted the iris. Now I have two areas where it is soooo happy. I’m going to use that homemade weed killer on it, epson salt, dawn white vinegar. I’ve let the mug wart get tall enough so that when I spray it, the spray only hits the mug wart not the plants below… Heat is on for today, 90’s are predicted, so I’m gonna cook the beast.

  11. Alexa Freeman says:

    I would give someone a lot of money (that I don’t have) to learn of a technique to get rid of mugwort. I’ve tried solarizing. I’ve tried cardboard and 6 inches or more of wood chips. I even did this in a defined area and kept it covered for three solid years. I’ve tried patrolling my yard daily and cutting each one off at the soil level so they would starve to death. Of course I’ve tried hand weeding. I’ve tried hoeing. The only thing I haven’t tried yet is torching which I will do this summer but I’m not optimistic. I won’t use herbicide but I’ve read that roundup doesn’t even work!

    Have you figured anything out yet? It is ruining all my beds.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.