naming weeds: hello, galinsoga and commelina

Galinsoga ciliata, or Galinsoga quadriradiata, a weedI HAD TO LAUGH when I read that Galinsoga, a vegetable-garden weed I’m all too familiar with (photo above), is also known as “gallant soldier” for marching forward energetically. A trooper, indeed. And finally—finally!—I know the name of the blue-flowered thing that looks like someone dropped some pieces of their spiderwort houseplant in my garden. Hello, Commelina. As always, I’m encouraging myself (and you) to put names to our weeds, because knowledge is power when it comes to beating them.  This week, two more names to perhaps add to your list. Anybody look familiar?

galinsoga wastes no time

GALINSOGA is also called quickweed; the Rutgers weed database says that’s because the seeds that follow its tiny, daisy-like yellow and white flowers start to germinate on their way to the ground—no waiting, and quick enough to produce multiple generations each growing season.

More than one species are listed in weed books; I have G. quadriradiata, which I actually know as its synonymous name G. ciliata, and I know just where it came from. A friend in New York City shared a desired plant a decade ago, and a gallant soldier was lurking in the pot, a hijacker. (Originally, it’s from South America, but is now widespread in the U.S.)

Galinsoga weed uprootedI recommend pulling this one as soon as it emerges–it thankfully comes out easily when young–or using a hoe to dislodge seedlings, being sure never to let it establish and flower. With repeat weeding or cultivating, I have kept it from becoming a wider issue.

Remember that a shovel with clods of dirt remaining on it, used in an infested bed then used in an infested one, can spread seeds of things like Galinsoga.  Clean tools between uses if you’re working around seedy weeds.

Bad infestation? Maybe do what environmentally conscious farmers sometimes must, and don’t plant the area for a season, instead cultivating repeatedly to disrupt the cycle of germination and establishment of an annual weed such as this.

Commelina communis weed emerging in late springa weedy spiderwort: commelina communis

FOR YEARS, as mentioned, I’ve half-imagined that bits of a former resident’s spiderwort houseplant had jumped out the window and planted themselves in the garden, but of course that’s not the story.  (If I lived in Florida or another warm zone, a “houseplant” a subtropical Tradescantia might in fact be one of my toughest weeds.) But for me the story is the Asiatic dayflower, Commelina communis, another widespread invader from (you guessed it) Asia. It’s in the same family as Tradescantia, so you, too, may notice a resemblance. This one has small blue flowers.

Commelina communis, uprooted and in flowerThere’s a native American Commelina species called C. erecta, but we don’t seem to have it hereabouts, according to reference sources on local flora. And besides, this particular pest I’m always pulling around now only appears in semi-shady to shady, cultivated spots in my garden where the soil’s been disturbed and I’ve brought in things from the nursery: classic weed modus operandi. Commelina communis is another common hitchhiker, especially pesky for garden centers. This IowaPlants.com page has a very detailed set of photos of all its parts, if you want to do a closer ID.

Asian dayflower is an introduced annual that reproduces by seed, says the UMass-Amherst Extension, which has good photos of a thick stand of it in flower. I’m happy to have no such photo of my own; that’s a situation I work my best to prevent happening here by pulling or hoeing the emerging seedlings, as with the Galinsoga.

Clearweedm or Pilea pumila

ah, the order of things

I KNOW, you’re probably thinking: Doesn’t she have anything to do with herself but figure out the names of her weeds, poor lonely woman? (That’s clearweed, or Pilea pumila, above.)

No worry; I haven’t completely lost it, or drifted away from civilization. This feels good.

There’s an expression, “A place for everything, and everything in its place.” Well, there is something about naming my weeds, putting one or two more a week into its place in the (dis)order of things, that I’m finding to be a lot like that. Even in the early summer jungle—which is what a garden after so much rain wants to be right now, flexing its unruly muscle at me—it feels comforting, and empowering.

Oh, and I love any excuse to stop all this incessant weeding and go inside, make a cup of tea, and look things up.

some other first-name-basis weeds

  1. “Gallant Soldier” is what I have, and I have it at the “holy jeez” stage. What a carpet of seedlings! I’ve got the Commelina too, but it’s not nearly as pesky.

    I agree that it *is* kinda nice to put names to these guys. I hate being ignorant about any plants, even the unwanted ones!

  2. annfsneff says:

    Yes, yes, yes. These weeds do look very familiar. I now have located my copy of “Weeds of the Northeast” and am also busy trying to identify my weeds.

    1. margaret says:

      Hi, Annfsneff. Good book! I am actually having fun with it all; really interesting.

      Hi, Lynne. Apparently both of these are eaten in some parts of the world, but me, I’m just pulling and composting them… :)

  3. Lydia Seibert says:

    It is important to name your enemy. My garden was open and 3 different men asked me what that weed is that is growing between the bricks in my walk (one of the chickweeds). They never saw any of the fabulous trees, special perennials, design and setting of my property, just that tiny weed. After all the work that goes into getting ready to share all your beauties! Some people, really!

    1. margaret says:

      I know what you mean, Lydia. And oh, those chickweeds…they manage to make a whole mat of chaos with only a tiny foothold, don’t they?

  4. I made the mistake of taking advantage of free mulch from our county compost site – now I have all kinds of unwanted things growing in my yard. But the worst are the ones I inflicted on myself: members of the mint family like spearmint and lemon balm; and “gifts” from my neighbors like honeysuckle bush and mulberry. Ugh!

  5. Patricia N. says:

    I bought euphorbia seeds many years ago thinking how pretty the yellow flowers would be by the side of the house in the spring. Didn’t imagine how ugly the plants would be after the flowers were spent, or how big the plants would get. Dug them all out but they keep popping up everywhere. It seems the seeds can lay dormant for years and then sprout up in the most unusual places, like far away from where they originated.
    The other plant that is driving me crazy is the wild blackberries. They keep coming from and undeveloped piece of land next door to mine and invading my flower garden. They are the hardest thing to get rid of, especially if they decide to come up in the middle of another plant like my montauk daisy.

  6. Jane Perrone says:

    I love finding out the names of weeds too! Current favourites here in my neck of the UK are pellitory of the wall (Parietaria officinalis), and selfheal (Prunella vulgaris) both once prized by herbalists. Oh, and ivy-leaved toadflax (Cymbalaria muralis) – I hear the flowers of this wall-clinger are used as a garnish on a signature dish at London’s famous restaurant The Ivy.

  7. The Coach says:

    Yes, that clearweed! I did notice the clear stem-what a distinction.
    These plants come to me from the nursery after my shopping sprees.
    They seem to inhabit greenhouses in the trade.
    At first, of course, I thought I had a bonus plant. What a letdown.
    Thanks for the heads up, Margaret.

  8. Judy Venonsky says:

    Thanks for the heads-up on the Commelina. They look so much like the seedlings I get from my Tiger Lilies – Lilium superbum I believe). Now I know the difference and will pull them out.

  9. Kingsley says:

    Thank you!!! These two are plaguing me-especially the Galinsoga, why doesn’t anything I want blanket the ground so efficiently?- and I kept meaning to look up what they are. As they say, knowing is half the battle!

  10. Adella says:

    On a completely different topic –
    Are organic seeds also GMO ?
    Are organic fruits and vegetables purchased at farmer’s markets grown with GMO

  11. Hannelore Passsonno says:

    Are there any weeds that are safe to throw into the compost pile (before they flower and make seeds), or is it better to discard any and all weeds?

  12. Betsey Keck says:

    Oh, my! I’ve just delved into the ‘weedy’ part of your post and heartily wish I had jumped in sooner. I think I am a crazy person but I see many of us have fallen for something we thought was splendid and found out it wasn’t. I am such a big fan of Commelina communis. It is beautiful. Its leaves are classic in form and its flowers resplendent in a strong, clear blue that makes my heart sing. I have even relegated a bed alongside my garage to it and been so pleased that it was taking hold and spreading happily. I gather that it’s a nasty weed but exactly how nasty is it? I love it. I don’t want to yank it up right away until I know more about the risks of keeping it around. Would you, please, elaborate?
    As for the Galinsoga I am hazarding a guess that it’s common name, Gallant Soldier, came from its Latin name. It’s really fun that they sound so similar. Oh happy day.

    1. margaret says:

      Hi, Betsey. I don’t think you are alone in thinking it looks like a garden subject; it is so much like may of our most common houseplants, and even a little like Tradescantia. Also: As mentioned and linked in the story, there is species of Commelina that’s a lookalike U.S. native wildflower in many parts of the country — so depending where you are, I suppose you could have that (but unlikely). How much an infestation you’ll end up with depends where you live (climate) and if you’re making it happy (which you are!). It’s an annual, meaning it’s not setting down permanent roots or rhizomes like the worst of weeds that one can hardly get rid of…but it can definitely end up all over the place by seeding around, as in those photos I linked to (nurseries often get big infestations).

  13. Dahlink says:

    Margaret, I want to thank you again for identifying a pesky weed for me last year–dodder. It looks like gold threads strangling plants in my herb bed. I am aware of it now and yank it out as soon as it reappears!

  14. kathny says:

    I just started noticing the commelina this year in the shady part of my garden. This year I also seem to have some new unwelcome visitors like yellow nutsedge, some type of bamboo grass that just appeared and took over one of our hills and poison ivy, which seems to be really bad this year. My normal pests are horse nettle, queen anne’s lace, bindweed in one spot in my garden that just won’t die, and pale swallowwort, which had pretty much taken over the property along with multiflora roses when we bought the place 20 years ago. We managed to wrangle the roses for the most part, but the swallowwort seems to still be popping up every year, no matter how much we pull it.

  15. joan packer says:

    Thanks for ferreting out the names of these weeds. They seem less overwhelming when you can identify them.

  16. mollie curry says:

    If you love the plant and want it where it is growing, then it is not a weed. I plant chickweed on purpose–delicious and healthy! I also love violets, and allow them to grow in some places and not in others. So they are garden “subjects” in some places, and weeds in others. Maybe those guys checking out the chickweed were lusting after it and wanted to take some to their own patios for between the cracks! Bermuda grass, on the other hand, is not wanted anywhere on my property because it is so hard to get rid of.

  17. Cynthia Nessel says:

    Oh No I think I have galinsoga infecting my dahlia’s. Big bummer! What a mess. I was kindof letting the weeds all around the dahlia’s grow to see what they ended up being, but that does not sound like the best advice. hhmmmm

  18. Nadia@Loveliveandgarden says:

    It is important to name them but unfortunately I haven’t named them all yet. There are so many of them!!! Just when I think I’ve identified it, I change my mind on its ID!!!

  19. mindy says:

    margaret, of the weeds you described, only tradescantia (the perennial) and Pilea pumila have we seen here. For us, the bane of our existence is aegopodium -which is directly traceable to a certain, aheeemmmm, 30-years-ago-neophyte who had gleefully brought home shared hostas from the original garden of Frances Williams,which had “some pretty 3 leaf plant ” growing in with them. What makes it the very worst of all weeds is its insidious and whisper thin root system that can squeeze itself into any space and flourish; and will, when and where broken, sprout new growth.You can understand when i say that i am not on the bus with all those who reach their later years saying they have no regrets.

    As to the plant introduced by old John T., I thought you might smile to see this that was printed last year in The Boston Globe:
    Tales of the City, Boston Globe Aug 26, 2012

    Kudos to all your great iwork, Margaret,

  20. mindy says:

    this is the reprinted story:
    “Over the past 25 years, my husband and I have created a mini arboretum on our property — we call it the Cotton-Arbo retum — that we open to the public. We usually agree on our thousands of plant varieties, but there is one, spiderwort, that I love for its flower and he hates for its invasiveness. The other day, I mentioned that I had read that if we were to cut it back after it flowers in June, it would regrow bushy and reflower in the fall. He met me eye to eye. “Is that before or after the Roundup?
    Mindy Arbo / Winchester

  21. Mary says:

    Ok I have all three of these… The worst being the clear weed its all under my raspberry s ..my roses. It does come out easily. So in my pjs with my coffee in the morning Pull away ..next thing I know an hours gone by… And no I don’t sleep in those pjs that night. It reminds me of a plant I had in my apartment back in the 70’s it was called Swedish Ivy. I was married to a Swede at the time …was I hood winked ?No more Swedish Ivy…no more Swede.

  22. “Doesn’t she have anything to do with herself but figure out the names of her weeds, poor lonely woman?” LOL! I’m grateful to finally know what that that awful pest galinsoga is called. I only had it in a shade bed at first and now it’s just about everywhere. I only wish someone would discover it makes good eating.

  23. rob says:

    I have those same weeds. Galinsoga is amazing to me because you can hoe it and it keeps growing (the hoe will pull up the root which holds onto a ball of dirt). So after a quick hoe, you must rake the uprooted plants into a pile and dispose. But if they get too big, pull it out will pull out the vegetable too. So I just snip it off at the base and let the plants shade it from coming back.

    Spiderwort seems to over winter via the tilled up root system. I try to rake up as much of the roots as I can after tilling (I also have bindwind, quack grass, and fescue grass). It is another weed that must be caught early or else you can’t pull it out without damaging plant or leaving a crater in the soil!

    Then I have the volunteer potatoes that I transplant to the potato patch up until it’s full. Then you just have to be firm about weeding them.

    Do you get lambsquarter? It’s great as a salad addition and in green smoothies as is dandelion (the young leaves).

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