naming weeds: hello, galinsoga and commelina

I 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.)

I 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.

a 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.

There’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.

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

• Clearweed, or Pilea pumila (photo just above the previous section)
• A weed I planted, Houttuynia or chameleon plant
• Garlic mustard, Alliaria petiolata
• Prunella and mugwort
• Hedge bindweed and spotted spurge
• How to ID your weeds—links to online guides
• Smothering weeds with cardboard and newspaper
• Piling on the mulch for weed suppression and control