October 13th, 2007
I Hate Horseherb


One of the first books I bought when I began gardening in Austin was Sally and Andy Wasowski’s Native Texas Plants: Landscaping Region by Region. I believed that one should garden where one is and was interested in discovering native Texas plants that would, not only survive in Central Texas, but thrive. However, Ms. Wasowski totally lost me on page 99 with this ode to horseherb, Calytocarpus vialis.

This plant illustrates how prejudices can cloud the mind. It is described in botanical literature as a “noxious lawn weed.” Why? Because it outcompetes grass in the shade. Funny, that’s what I thought everyone wants a shady ground cover to do.


Well, honey, call me prejudiced but I’m here to tell you that horseherb is a noxious weed. It’s right up there with bindweed in my book. It will grow in your lawn. It will grow in your paths. It will smother the buffalograss. It will climb over the agave. It will suck the life out the species tulips. It will crowd out the bluebonnets.

In short, if you have it, you will never be rid of it. Try pulling it up, and it will snap off at the ground and resprout again in a few weeks. Dig it up and every little root will start a new plant.


Still, I’m resigned to the digging out method. Here I am, digging up the meadow and adding compost. The meadow needs to be disturbed a bit this time of year so that the self-sowers (larkspur, bluebonnets, cilantro, and nigella) will sprout. Unfortunately to get out the horseherb, I’m also digging up rainlilies and tulips and buffalograss and the nice gravel mulch I have around the agave. What? You can’t see any gravel mulch around the agave? Now you know why I hate horseherb.

by M Sinclair Stevens

17 Responses to post “I Hate Horseherb”

  1. From nelumbo in SC:

    It’s funny how the line between “native” and “invasive” can blur although they are often presented as opposites.

    Horseherb sounds a lot like my English Ivy problem…it’s taken over the front yard. Blah. I think I’ve decided that I hate the concept of groundcover.

    Groundcovers can be tricky. One rainy year I let the English ivy take over the south border because it was such a nice deep green, a color we love in our dry dusty summers. Of course, I quickly regretted it. Now I’m quite vicious hacking it out but it’s a losing battle. — mss

  2. From Pam/Digging:

    I just read that section of the Wasowski book again recently, and I thought they were nuts too. I didn’t realize just how invasive horseherb is, but aside from that it’s not attractive at all.

    My biggest nemesis, however, is some unnamed trash tree in my neighbor’s yard that sends suckers clear under my driveway to pop up here, there, and everywhere in my garden. I’ve tried digging. I’ve tried spraying. I’ve tried pulling. Ha! It’s the roach of plant life; I’m sure it could survive a nuclear holocaust.

    That sounds nasty, Pam. I’ve been keeping an eye on my neighbor’s bamboo but so far it has played nice. — mss

  3. From Annie in Austin:

    Hello MSS,

    There’s a good-size patch of Horseherb in the parkway in front. Anything green that’s mowed is called ‘lawn’ but maybe I should keep my eye on this plant!

    Annie at the Transplantable Rose

    It can look nice when watered. And I used to treat horseherb like “lawn” too in some situations. But now I’ve declared all out war. I’m taking no prisoners. Die! Die! Die! — mss

  4. From Steve Mudge:

    I use the digging method whenever possible too but Horseherb, well, my wife wanted to stay as native as possible so we let it grow…for awhile, then after digging out the same patch three times we got out the Roundup–that stuff is really very good with getting in and killing the roots and its toxicity is quite low.

    In desperation I’ve tried Roundup on a patch in the front lawn. It didn’t have much effect. Next I’m going to try 20% vinegar solution. That’s supposed to be able to kill even poison ivy. The trouble with any spray solution is killing the nearby plants. But then, I have that problem with digging, too. Aaaaagh! — mss

  5. From Carol:

    Horseherb sounds like a terrible plant to have! You have my sympathies.

    But at least I don’t have to battle moles. You have my sympathies, too. — mss

  6. From Rantor Austin:

    Pulling it does work eventually. It’s gone from every place but one, a strip that the City dug up and left with the topsoil buried and the caliche on top a few years ago. I kind of like the papery feeling of the leaves, which nobody ever seems to mention. I’d be afraid to use Roundup (read about glyphosate). It sinks down and also runs downhill and gets into our drinking water. A neighbor used it a few weeks ago (spray version) on what he thought was poison oak but was really passion vine. He pretty much killed the passionvine (habitat for zebra longwings and for gulf fritillaries) and the drift killed a whole lot of other things besides, most of them ours.

  7. From Marj, Decatur TX:

    Oh, goodness. I guess we all do march to different drummers!

    I love my horseherb — in fact, I had to BUY it. It is the only thing that has survived in my heavily-shaded, very dry, western exposure, red clay front yard. Wise County had one of the original brick plants for Acme Brick Co., and I’ll swear they could have mined our clay and not needed a kiln!

    We’ve tried everything in the thirty years we’ve lived here, and the nice green groundcover with those tiny yellow flowers are finally taking hold — after three years.

    Luckily, we’re in the country, so no neighbors can complain if it escapes.

    I wouldn’t mind it so if it didn’t grow where I didn’t want it. — mss

  8. From Samantha Hunt, TX:

    I find horseherb absolutely wonderful. It outcompetes grass in the shade and makes a wonderful ground cover. If anyone is wanting to get their horseherb off to a great start, trying throwing barbecue ashes on top of them. Don’t even water it in, just spread it over the top and your horseherb will take off like it’s on steroids. Thanks!

  9. From Samantha Hunt, TX:

    One more thing, I pity the poor fools who use all their time and money trying to force their yard to look a certain way (like everybody else’s in the Stepford community.) Save yourself time, money, and discouragement and let be what wants to be. You will find that some things you consider weeds, some people in other parts of the world actually BUY to plan in their garden. Therefore, actually there is no such thing as a weed. Such as the Asiatic dayflower. It’s nasty and scraggly looking, but if you water it and give it a good haircut every time you mow, it grows into a beautiful mass of blue flowers.

  10. From Trinity, Texas:

    How do you kill the nasty coca burrs in your yard. My yard is being over killed by them. Someone suggested putting St Augustine grass seeds out…please help if you can…thanks.

    I’ve never had this problem. However, I read recently in the Texas Gardener that if you fertilize the area well that it kills off the burrs. I’ve never tried this so I can’t say from my own experience. — mss

  11. From Danny (Austin, TX):

    I love my horseherb. It’s growing in many different spots voluntarily after I removed my St. Augustine lawn (I mulched and have installed low-water plants). I may indeed live to regret letting so many thrive…I will not let them interfere with my other plants. If that happens, I will trim them back or just pop them out of the ground. They don’t seem too bad-tempered like nut grass (nut sedge) or bermuda grass, both of which are blood-pressure-raisers for me. Count me as (currently) a big horseherb fan.

  12. From Rebecca in Flower Mound:

    I have liked it, but now it seems to be outperforming the bermuda grass in the sun. Should I expect to lose all my bermuda? I personally wouldn’t care if the entire back yard was just groundcover, but what will it look like in the winter time?

    Horseherb might die back some in a freeze but it comes back rapidly. For me it’s generally green in the winter but brown in the summer if we’re having a drought. It doesn’t mind being mown back. Personally, I think it always looks terrible. — mss

  13. From Stanley Austin:

    I have minimum sun (trees) in my back yard and would like to find Horseherb seed…do you have any suggestions …thanks Stanley

  14. From Jean Austin, TX:

    For some reason my dog likes to eat Horse Herb and everytime will throw up that night. Won’t eat her food the next day. Is it a poisonous plant to animals?

  15. From Bryan Austin, Tx:

    I hate my horseherb!! It’s really taking over my St. Augustine. If anyone finds a surefire way of killing it, please post. I will gladly donate to whomever wants to come and dig some up.

  16. From CR Smith, Allen TX:

    Horseherb grows great in Allen TX. My neighbors planted it (2-3 starters in the back near the alley)and now it is invading my flower beds…even those in the front. It took 2 years to spread from the back to the front of the lots. Now it’s in several yards. I had a 5″ deep concrete barrier installed between the yards as I don’t like using so much Round-Up. I wouldn’t mind it so much if I could keep it out of my flower beds. It’s really invasive.

  17. From Kathy Fry Canyon Lake:

    if you still have some horseherb I would love it. My daughter lives there in Austin TX and I live about an hour away. I would take all you would let me have.

    RSVP ASAP Please
    Kathy Fry