plant it once, have it forever

There’s a prominent Northern California nursery* that advertises on its website that a variety will self-sow and naturalize. Or in its peppy, enthusiastic way: “Reseeds!” One of the plants so listed has a followup note: “Due to agricultural restrictions, we cannot ship this plant to Arkansas, New Jersey, New York, Oklahoma, South Carolina, and Texas.”

Read between the lines: This plant, under the right conditions, might just run wild, out of control, and take over your garden or an ecosystem! (Not all plant restrictions are based on their invasive potential, however. For instance, some might be controlled because of known pests or diseases the species may harbor.)

Over the years I’ve added interesting plants to the garden, only to have them sow and propagate themselves all over the garden. For most of these, I don’t worry huge amounts that they’ll escape to the nearby wilds because they’re wimps when not pampered in a garden, but with regular watering they’re aggressive thugs. Pretty thugs, to be sure. But still thugs.

Here are a few of my mistakes. Some are merely annoying. Others require multiple hours of labor every year to keep under control. Colder areas might not have the same problems with these that I do, but I’m sure you have your own monsters. (My apologies in advance to the fine nation of Mexico. I just noticed that four of my selections have “Mexican” in their common names…)

Mexican petunia (Ruellia brittoniana). Pretty, tough. Also pretty tough to eradicate in my garden once it got a foothold. I should have paid attention when the guy at the plant sale warned me that it might spread. According to Floridata, “Mexican petunia is listed as a Category I invasive species by the Florida Exotic Pest Plant Council. This means that it is ‘altering native plant communities by displacing native species, changing community structures or ecological functions, or hybridizing with natives.’ This warning applies to all parts of the state of Florida (and other areas with similar mild climates). Where hardy, the Mexican petunia excels at invading wetlands.” It also can be a nuisance in a dry garden like mine where it spreads underground and via exploding seed pods.

Mexican fan palm (Washingtonia robusta). Maybe it’s a uniquely California thing: You go out to the garden to pull weeds, and along with the crabgrass and spurge, you end up pulling up little palm trees. Folks in colder climes might be thrilled to have some of these, but here they’re a nuisance. Our Mexican fan came with the house, and it took us a few years to finally remove it. All that time we were yanking baby palms all over the front yard, and the seedbank remained viable for several years afterward.

Mexican feather grass (Nassella tenuissima). I’ve dinged this plant several times before. I won’t add anything more here other than to note that I’ve probably pulled up a hundred seedlings this season. At least this is down from the orgy of seedlings that I had when there was a harem of adult plants in the garden that apparently had nothing on their mind except sex and reproduction.

Mexican evening primrose (Oenothera species, I think it was O. speciosa). I was on vacation at the Grand Canyon in 1991. Innocently I bought a packet of seeds of these that were sold as a “wildflower.” I was thrilled when they came up the first year and I had a gregarious patch of delicate bright pink flowers where there’d been a patch of dirt previously. Little did I know they’d resow and spread by underground runners and continue to annoy me to this day. Wild flower, indeed.

Sweet alyssum (Lobularia maritima). Don’t let the “sweet” in its common name fool you. I continue to weed alyssum seedlings popping up around the garden from a single packet of mixed colors I planted in the late 1980s.

Fortnight lily (Dietes iridioides). A few clumps of these came with the house. The tough, hard seeds lay dormant in the ground for years and plague you with unwanted seedlings long after you’ve removed their source.

Calla lily (Zantedeschia aethiopica). I’ll have to admit that I have a soft spot for these plants and don’t pull them out the same way I pull out other unwelcome plants. My parent’s house came with a fifty-foot foundation planting of them on the north side of their house. The way the plant can spread, however, now makes me think the previous owners might have started with just a half dozen plants. Feral callas are plants of concern in some California wetlands. A couple well-watered garden spots seem to generate calla lilies out of thin air.

Epazote (Dysphania ambrosioides). I won’t quite call planting this Mexican herb a mistake, since I use occasionally in cooking. It does spread about the garden a bit, however, and pops up in unexpected places. There are reports [ including this one ] that it’s colonized parts of New York’s Central Park–though that’s not my doing. I popped over to Wikipedia and learned this pretty interesting detail I’d never heard before: “Epazote essential oil contains ascaridole…; in pure form, it is an explosive sensitive to shock.” Botanical TNT–Wild!

To my mistakes, I’ll add some native California annuals and perennials that have been really successful in reproducing themselves in my garden. Currently, my plants are wandering around an area where they’re desired and haven’t escaped far. I won’t call them mistakes at this point, but I can see that they could become unwelcome in some situations.

California poppies (Escholzia californica). What? Our sacred state flower?! Well, there are some unwelcome escaped colonies in Chile and Australia. And the seeds regularly find their way into cracks in the pavement.

Baby blue eyes (Nemophila menziesii). Not really what I’d call a thug, though these seem to be pretty successful at reproducing themselves. It’s easy to pull out the occasional unwanted plants, but who’d want to?

Clarkia (Clarkia spp.). I haven’t grown many clarkia species, but the one that seems to wander around the most for me is C. rubicunda ssp. blasdalei.

*There’s a good chance you’ll have guessed the identity of this well-known nursery if you’ve spent any time at its website. I don’t mean to diss them at all. You can get potentially rambunctious plants from virtually all nurseries, including those dedicated to native plants.

10 thoughts on “plant it once, have it forever”

  1. A timely post! Let’s add to that a Persicaria that I bought from a nursery that swore that this particular Persicaria was not invasive at all. Well, I dug it out and spent the next summer digging up runners in a no-water situation. I think that did it, though.

    And don’t get me started on the mexican feather grass…

  2. My gardening is still at such an early stage that it’s thrilling to me if any plant manages to reproduce itself, and I haven’t yet regretted any of them. The plants that have sprouted fairly abundantly from seeds I’ve scattered on the ground include Clarkia unguiculata, Collinsia heterophylla, Eschscholzia californica, Layia platyglossa, Lupinus nanus, Lupinus succulentus, and Nemophila menziesii. Those are all fairly predictable candidates, but some other predictable candidates haven’t been as successful. For example, Lasthenia californica sprouted abundantly in pots for me, but I only got one or two surviving seedlings from the seeds I scattered directly on the ground.

    We have a single sweet alyssum plant with purple flowers that has been here for years and has only ever produced one seedling that I’ve noticed, and that one seedling didn’t survive. Our alyssum is under the front porch roof, with heavy shade, little water, and surrounded on two sides by cement, which may help explain why it’s not spreading.

  3. I had to explain to my aunt the significance of “Due to agricultural restrictions…” I like that nursery and it’s one of our main sources for plants, but the website is sometimes a little like mexican feather grass or oenothera, seducing you with all that beauty… It has a lot of good info, but also requires a certain amount of reading between the lines.
    I wish I could get Baby Blue Eyes to reseed in my garden.

  4. Mexican Evening Primrose is the WORST! One of my master gardener friends who has been on the bringing back the natives tour several times makes a point of adding a sign explaining how invasive it is out of fear visitors will race home and plant it.

    I know you and TM will strongly disapprove, but I must confess I still use Mexican Feather Grass on occasion in smaller, protected gardens. Is there any other plant that has that same gorgeous wheat color? And don’t suggest Carex, my clients always think I ordered them a dead plant when they see it.

  5. James,
    Just yesterday I was bemoaning Lirope ‘Silver Dragon,’ not a plant that self-sows, but rather, runs and runs below ground!!
    On the other hand, Cerinthe has now naturalized and I’m enjoying its best year ever in my Spring garden.
    btw …I wonder if you noticed that although Mexican feather grass is considered invasive, it is planted as a major element at Cornerstone Sonoma in the Van Sweden garden AND the Pamela Burton installation. Cheers,

  6. Great post. I know of the NorCal nursery you are referring to, as I’ve been a regular customer of theirs for the past 3 years. Indeed, I’ve raised my own eyebrows over their peppy mantra of “Reseeds,” as reseeding with reckless abandon is not necessarily a desirable trait for any garden plant, native or non. But I still love their selections of native annuals (including the Clarkias), which have “gently” reseeded within the confines of my annual wildflower bed.

    Epazote is another story. I love Mexican food so planted one in my herb garden a couple years ago. It flourished, flowered, and disseminated its seeds EVERYWHERE. So in my book, it’s now officially a weed.

  7. James, great subject to raise in spring, when fantasies flourish as much as potential weeds.

    Epazote! an herb I have tried, and failed, to grow. I always think it’s funny how one person’s weed is another person’s difficult plant – though obviously some of the plants here are a little more serious than that.

    Nemophila menziesii (and also N. maculata) aren’t dangerous if you plant them in a place that doesn’t get summer watering. They both grow wild here but are never invasive; I try to “help” along colonies by seeding around where I live.

  8. I guess it’s location, location, location. I’m still trying to get over seeing broom for sale at a local nursery. You are apt to notice that “reseeds” and “invasive” are really the same thing. . . Wish there was some sort of truth in labeling program at all the nurseries. I second Ryan on Baby Blue Eyes envy. They have no love for me!

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