Is there a plant in your garden that you once longed for and now wish you could get rid of? Meet mine: Mexican evening primrose (Oenothera speciosa).
You can see why I wanted them. Mexican evening primroses form diaphanously lovely, cloudlike mass of pink. I had seen them in other gardens, and wondered why no nurseries sold them. Finally, I found some at a farmer’s market. But once planted, the primroses drooped and disappeared. So, I bought some more. Same thing—I couldn’t seem to keep them going. Imagine my surprise when, the following year, I had primroses galore. It seems their topgrowth dies back after blooming, but the roots are still alive. Great, right?
Wrong. Guess I should have paid attention to this part of the description in the Sunset Western Garden Book: “…can be aggressive and potentially invasive.”
It seems Mexican evening primrose is so accustomed to inhospitable growing conditions—dry, rocky, nutrient-poor soil—that in a cultivated garden, it goes wild. Here you see it cavorting around a bewildered Agave americana ‘Marginata’. Oenothera reproduces via underground roots that send forth new plants.
Five or six years ago I sifted the soil in my flowerbeds to get rid of primrose roots. I was determined to win, and I thought I had, for a while. But it seems even if you go after the plants with a vengence, if the merest root remains, Mexican evening primroses bounce right back.
After observing that the roots grow readily downhill but never uphill, at least, not on an unwatered, decomposed granite slope, I transplanted some to my garden’s most inhospitable area: below the fence, along the road. Here you see the result. I’m actually pleased. (Score one for Debra.) That shrub behind the sign is a mallow, btw.
I also grow a white variety of Mexican evening primrose that doesn’t seem to be as invasive.
Last summer I relandscaped a section of the garden. The primrose had naturalized nearby, but was safely (or so I thought) on the other side of a pathway. I didn’t think its roots could—or would—cross the path. But it saw a golden opportunity (rich soil, full sun, lots of room) and has popped up amid young plants that are not yet established. It’s fairly easy to pull out of friable, well-mulched soil. But the taproot is like rubber, and it stretches and then snaps.
I am loathe to use chemicals, but I may go after the plants with Round-Up. Seems such a shame, with flowers as pretty as these. So, first, a bouquet…with mallows.
(Hours before this was scheduled to be posted, look what I saw in the garden. OK, primroses, you have a reprieve. For now.)
I remember these beautiful primroses from my childhood in Mississippi, where they have naturalized. They didn’t seem to be such rampant growers there, perhaps because of the very humid summers and heavy clay soil. They would bloom profusely along the roadsides in spring, then disappear.
It’s the way they disappear after blooming that makes it seem they’re annuals…but they’re busy establishing roots to return the following year. Debra
Oh, goodness, yes. This stuff gets everywhere. At least it gives me something to destroy when I just really want to get out my anger on something…
And yes, the butterflies and bees do love them. Plus they are pretty and bloom for a very long time!
Good plant for those places where nothing else will grow, but watch it carefully…
There actually are some places where it’s ideal. Like roadway medians! Debra
Interesting! I had a lovely spot where it came up every year. But then i lost it during a building renovation & I’ve been looking for some to re-plant. Gonna have to re-think.
PS. Your book DwSucculents is sitting next to me on my desk. Nice to find you online.
Ah. A building renovation. I hadn’t thought of that as a way to get rid of them! Debra
Thanks for that post. I have poppies galore in spring, and this primrose seemed such a perfect follower for summer.
But I did some research, started to worry, and resisted. Still, every once in a while, I’m tempted again. I needed to hear this….
It wouldn’t be so bad if they flowered when nothing much else was going on. But they bloom when everything else does. You can do better! Debra
I had it at my last house along with some mint in the ground! We worked for years & never really got rid of either……be careful!
I’ve had mint take over, too. Mine is growing in shade where it’s battling for turf with sword ferns—which I also wish I’d never planted. Debra
The pink primrose is considered a weed in my area but they look so beautiful growing along the roadsides. I remember picking them as a child on my way home from school.
They seem to have spawned happy memories for several people. I have happy childhood memories of dandilions and wild oats…two plants I certainly wouldn’t welcome in my garden now. Of course when we were kids, we weren’t gardeners! Debra
I’m not surprised. I saw these growing along every road and in every traffic island when I was in Austin. They were the first plant besides the bluebonnet that I learned to recognize. They are pretty.
They are indeed. I think that’s why I let them get away with so much! Debra
They found their way into my garden by accident. Your description of rubbery tap root is apt and there seems to be no easy eradication! But they are lovely. gail
Hi, Gail — There was a time when I envied people who had them, and figured they must be amazing gardeners to grow them. But no primroses found their way into my garden by accident. Alas, it was all my doing. Debra
I had my patch stripped down to a few plants, but they were so pretty I thought I’d try growing them in a pot by my front door. Son of a gun, the roots went thru the hole in the pot and tried to root in the ground so they could take over a new spot! That was the last time I tried that.
Now that I am getting ready to sell my house, I have let them take over again in the original spot. Let the new person deal with them, heh heh.
Hi, Bev. Hmm. Selling my house would solve my primrose problem, wouldn’t it? If your home’s new owner isn’t into gardening the primroses won’t be a problem. It’s only when they strangle your prized plants that they’re infuriating. Primroses are like well-dressed party guests who get a little too happy and then are obnoxious. Debra
Oh, I so feel your pain! This was one of the first things I planted, my first spring as a gardener, from seed. It is lovely, smells sweet, makes a great cut flower, but YIKES! I am forever yanking it out. Perhaps I’ll go guerrilla plant some in some otherwise neglected spot where I can drive by and see it, but won’t have to battle it for my garden.
Do they smell sweet? I hadn’t noticed. At one time I had such clouds of primroses, I wanted to fall into them and swim around. Their scent would have reinforced the fantasy. I wonder if my primroses are not particularly fragrant, or if there’s something wrong with my nose. I think I’ll go outside and find out…Debra
Too bad they are so invasive they look so pretty and the butterflies seem to like them.
Bees, too. And ants. And aphids. Debra
I did a post all about that a while ago.
http://healingmagichands.wordpress.com/2007/09/27/nimby-plants-i-would-never-plant-again-oenothera-speciosa-showy-evening-primrose/
What I found is that if you will be persistent and keep pulling out the new growth when the roots sprout, eventually the primroses will die out. I started my total eradication plan last year and this year I have only had about four places where they came up.
Fortunately, they are easy to pull up.
At one time I got rid of nearly all of them, too. A few came back, but I figured I had them licked, and they were so pretty…well, this is one persuasive plant! Debra
I’m so glad that I read this. It reminded me why I should NOT buy the gorgeous ‘Lemon Silver’ evening primrose that I was drooling over today at the nursery. (I don’t have a slope that needs to be tamed, unfortunately!)
Well, Kim, I sure hope I haven’t steered you wrong. There are numerous species of Oenothera as well as cultivars. These may not be invasive, in fact, my own Oenothera speciosa ‘Rosea’ may not be a rampant pest in other growing conditions and regions. I’m not familiar with ‘Lemon Silver’ but it sure sounds lovely—maybe your nurseryman can advise you? And if you find out something worth passing along, would you let us know? — Debra
Hi: I have Mexican Primroses, they are just lovely. However mine have bloomed for the season and do not know when to cut them back.
Hi, Hazel. If you find the spindly stems unsightly, shear them off at ground level. The business part of the plant is underground, and trust me, it’s alive and well. — Debra
uh-oh… I swore I wasn’t going to put another yellow flower in my garden but I just bought a lemon sunset evening primrose. In fact I almost bought 2 because they’re so pretty. Now I don’t know whether to plant it our not.
I love this site, your comments are hysterical, but I wish I hadn’t seen it. Now if I plant and have problems I have no one to blame but myself. I was on another site and it said they don’t have any problems with bugs, beautiful plant etc etc… I should have stopped there! Maybe I’ll plant it in the wooded lot next door. Thanks for the info…. kinda
I despise this one too! It was already here when we purchased our house, I can’t stand the pink, it seems to spoil the orangey-red, purple, and burgundy with blue thing I have going on. But the squirrels love the petals…
Hi, Erica — I wouldn’t mind Mexican evening primrose so much if it bloomed in summer, fall or winter, but it goes gangbusters when my spring garden is at its peak. You’re right, it does compete with oranges, reds, and blues. But, like your squirrels, I love the petals (not to eat, though, just to look at!) Debra
I’ve had this stuff for about o say 6 years. Have been trying to get rid of it the past 3 or 4! I have pulled it all up, round up, round up, round up, and yep you guessed it MORE ROUND UP! I would love to just see the stuff die. It’s in my yard half way down my house…..WHAT WAS I THINKING???? I was told to try gasoline anyone tried this yet?
Hi, Steph — I sympathize. Re gasoline, you’re kidding, right? Fire hazard aside, I can’t imagine that would be good for your soil. — Debra
Wow, I’m so sad. People try to grow things as bland (and thirsty) as, say, St. Augustine, while pouring roundup on our native? They look so great tangled with that agave, too. Actually, all the pictures look great, except for the dead one. I’d have a lawn of them, if I had a lawn.
(Caveat: I’ve lived in south Texas, where it is too dry to become rampant; and Houston, where it’s frequently too wet. And I like pink. And I don’t mind dandelions, either.)