May 9th, 2003
Acanthus mollis

photo: Acanthus mollis
2003-05-09. Acanthus mollis. Austin, Texas. (zone 8)

Everyone who visits my garden in April or May is stopped dead in their tracks by Acanthus mollis. It’s so big. And it’s floral spike is bizarre and somewhat menacing.

Acanthus mollis is not really a good landscape plant in Austin, although it can be useful if you have a very shady site. It needs lots of water. As soon as the temperatures reach the 90s, it wilts and looks about as attractive as cooked spinach. Once the summer gets really hot, it fades away leaving a big hole in the border design. But when temperatures cool off in the fall, it’s back again. Fall and winter (if it’s not too cold) are it’s best seasons. In spring, the leaves are often ravaged by spring cankerworms and whatever beetles are about.

It’s one tough plant, though, and keeps coming back despite my neglect. People in more temperate climate consider it a pest.

photo: Acanthus mollis
2003-05-09. Acanthus mollis. Austin, Texas. (zone 8)

by M Sinclair Stevens

35 Responses to post “Acanthus mollis”

  1. From Magnolia Angel aka Karin (The Netherlands):

    I planted an Acanthus mollis a few weeks ago but it still doesn’t grow much. It has been very wet during May in the Netherlands but now we have very hot weather. I really hope my Acanthus mollis will be so beautiful as yours in the future.

  2. From Georgia Davis (Austin):

    Was surfing to find into on Acanthus mollis and lucked into your site. I’ve lived in Austin for 46 years now (Bubbaland for the last 6). My garden area here has an awful lot of shade, also. House was built in the 1950s and has three mature trees…a real blessing in this heat. This is the second summer for my acanthus plants and they send up their spikes for the first time this year. Awesome, indeed.

    Was able to provide lots of water last year, so they weren’t very “droopy.. This year I’m rather housebound with a broken fibula and torn ligaments, so depend on hubby to water…thus, the droopy acanthus plants.

    We were wondering if the plants died after flowering, and perhaps self-seeding, or what. Hope not ‘cuz they are gorgeous huge plants. Please let me hear from you concerning your experience with them.

    Enjoy your site and will drop in again, very soon!

  3. From Scott Cupples (California):

    I have always considered it to be a big pretty weed. In southern California, I have one growing in a secluded part of my yard. Little summer sun, never watered in the summer. In November-December has brilliant green foliage and in spring sends up the central stalks. In summer, it dies off and I mow it down with the lawn mower clear to ground level. Comes back up every year. I starting to become fond of it now.

  4. From Tina (California):

    We have a bunch of Acanthus mollis in our garden in the San Francisco Bay Area and I have come to loathe the plant. It spreads like crazy and has infested every part of the garden. Nothing grows nearby as it sucks up all the water. I have been trying to get rid of it by digging it up but out of every last little piece of root a new plant grows (I have been digging up the same spot three or four times now and each and every time I come away with buckets full of roots). I am about ready to hit back with chemical means because I want it out of my garden, all of it and soon.

    Any suggestions on how to get rid of this sucker are highly welcome!

    2004-01-12. I visited San Francisco last summer and saw an amazing stand of Acanthus mollis in Golden Gate Park. One gardener’s weed is another gardener’s treasure, although that seems to depend on how difficult it is to grow the plant. Here, Acanthus mollis is a bit of a challenge because of the heat. I guess you can put up with months of heat, humidity, and rainlessness (as we do in Austin) to keep Acanthus under control, or live in a cool, pleasant clime and be besieged with it. The best advice to you, therefore, would come from a gardener in San Francisco area. — mss

  5. From Phil (Australia):

    I’m surfing the web right now to find a way of getting rid of this weed, and came upon your site.

    We have one of these monsters in our backyard, no matter what we do it seems to have taken out a mortgage on that patch of ground. Adding to my woes is the fact that I made the mistake of moving some soil around the garden… guess what? baby acanthus all over. The guy that owned the house before us said he had been trying to get rid of it for 20 years.

    Chemicals are a way to go. Anybody have any ideas to help a Desperate Aussie?

    Oh… and I know that there are some folks out there who think this is a nice plant… well each to his own.

  6. From Liz Stewart (Great Britain):

    Im amazed reading some of these comments. I live in the UK. I have four a.mollis that hardly grow despite tlc and plenty of pleading. They are considered quite exotic here, also rare. Very few people have them!

    Both of my a.spinoza are going to oblige me with a flower after just planting them last autumn. I love acanthus more than any other plant in the garden. And if they want to seed all over the garden–well what is it you Americans say–“Bring it on!!”

    Where in the UK? My husband is from Cheshire (southwest of Manchester). I love A. mollis, too; it’s big-leaved and tropical-looking with faintly sinister flowers. It’s blooming right now, but as the temperatures have finally reached the 90s, the leaves are beginning to wilt. It won’t last much longer this season, but it will come back in the fall when the temperatures drop. I think the people who dislike it live in the cool, wet Northwest. — mss

  7. From Janelle Hoffman (Oregon):

    When I first moved into my home in Oregon, I didn’t know what it was. It reminded me of the plant from the Little Shop of Horrors, it just didn’t want to die or go away. It was in a separate bed next to a concrete sidewalk and the roots grew under the sidewalk.

    I don’t have a solution. Just be careful where you plant this one.

  8. From Karen (California):

    My parents have an Acanthus mollis growing under an oak tree in Healdsburg, CA, and it’s been there for decades. It spreads only a little every year. They never water it (one doesn’t water under oak trees), and it grows big and green just as soon as the rains start in the fall, flowers in the late spring and dies back to nothing in the heat of the summer. They literally do NO maintenance. It’s a truly spectacular plant, and I can’t recommend it enough for creating that lush, green look under oak trees. You have to be comfortable with the look of the summer die-back, but if you’ve come to appreciate native plants out here, that’s just part of the package and part of the seasons.

  9. From Dan (Georgia):

    I am starting to feel a little apprehensive now about the Acanthus mollis that I just stuck into my bog garden. I live in Atlanta and asked the nursery man if it was invasive. He said “No, it just forms a nice clump.. I am going to hunt him down if it goes bamboo on me. I already have a nice spread of horesetail reed grass (scorpiodes equestriae) that I have to keep an eye on. I’ m hoping that the hot and humid weather here will keep it under control. I keep the area pretty moist. Of course, it is not too late to move it to a different area–like behind my pool pump where hardly nothing else will grow and let it spread all it wants to. Any suggestions?

    I also scored a “Summer Beauty” acanthus which is a hybrid of the mollis and the spinosus. Apparently, it comes from a garden in China and is more heat tolerant and slightly smaller (3’x3′)but still produces a tall flower. Y’ all should snag one if you ever come across one.

  10. From Earle:

    I have read that “after flowering, explosive pods scatter seeds over a wide area…” Are these pods on the flower spikes? If not, where are they and what do they look like.

    Have ‘Summer Beauty’ in a large planter to prevent root spread but would also like to insure against spreading from exploding seed pods. Would appreciate any info on this.

    To my knowledge, mine has never set seed. I think it gets too hot in Austin just as the A. mollis is flowering. I’ve never seen any exploding seedpods (except on bluebonnets). And no little seedlings have popped up nearby. — mss

  11. From CNS (Texas):

    Is the Acanthus mollis deer resistant in Central Texas?

    According to G. S. Thomas in “Perennial Garden Plants”, deer tend to stay away from acanthus in general. I can’t say from experience because I don’t have deer. In my garden, it’s the hot temperatures that make this plant ratty from May to October. — mss

  12. From Rebecca Dubose:

    My Acanthus is wonderful. Today, I noticed spikes peeking above the foliage. After the spikes die, my plant dies completely back and immediately leaves begin coming back. Except for those few weeks, it is green and lush the rest of the year. Bugs don’t bother it. And I dig up the babies I don’t want and add them to the compost pile.

  13. From Tony (Australia):

    I really need to get rid of these monsters. Does anyone have any idea? My monsters are popping up some 20 metres away from the parent plant! I have dug, I have poisoned, and I have dispaired, short of covering the whole garden in concrete and using it as a carpark, I am at a loss for ideas.

  14. From Ronn:

    Has anyone in the Seattle area had any experience with this plant? Any problem with it being invasive?

  15. From Bill (Seattle):

    Ronn, re your question about Seattle experience: I’m searching for more info because of short Q&A in The Seattle Times this morning. There was no mention of invasiveness, but I’m still leary. It’s at the following link. The author may be able to help with more info.

    And Liz from Great Britain: I appreciate your humor, but only some Americans say “Bring it on!.

  16. From Pam (UK):

    My acanthusis is magnifisent. It has large healthy tall flowers and is looking most majestic. However the leaves are covered with what looks like a white fungus.
    Any suggestions?

  17. From Mara (west of Austin):

    I absolutely adored my “Bear Claw”, aka Greek pattern plant, even though my visiting sister from New Zealand made the sign of the cross with her fingers to ward of it’s evil. She did that when she saw my oxalis too. I moved and took one of the bear claws with me. It did not like it under my new oaks west of town. The thin leaf mulch above limestone was not its cup of tea. I gave it 2 years and then sent it back to an old neighbor in the old hood who absolutely adores it. Is happy as can be now but not greedy as they are in California. Did I say, that I absolutely adore them.

  18. From Gail:

    I live near Seattle and have it in my garden. From everything I’ve read (and experienced) it is not considered invasive here. It is tolerant to zone 7 and prefers a hotter, same dryness, summer than we usually experience. This summer was considerably hotter (many days well into the 80’s rather than our typical 70’s) and has not gone wild. I also have have acanthus spinosus which seems hardier and perfers more sun.

  19. From Linda (San Antonio):

    I live in San Antonio. I’ve been browsing this great blog.

    Having heard that acanthis mollis can’t tolerate our heat, I didn’t give them a second thought.

    But, gosh, I’m always looking for something that will grow in the winter!!!! (Especially something that looks a bit on the exotic side!!)

  20. From Rose (Chicago):

    I have been looking for deer resistant plants to start from seed and acathus mollis was one recommended. I bought seed and am now wondering after reading thru the posts, if this should be direct sown. I hope to grow this plant here in Chicago, IL and in Aurora, KY. Chicago is Zone 5; Aurora Zone 6. Both areas get hot and humid in the summer but KY can get over 90 degrees. From the photo I’ve seen the plant and it looks stunning to me. I use soaker hoses with timers in both areas to keep the gardens watered. Any suggestions on growing from seed will be appreciated.

    I’ve not grown Acanthus mollis from seed. I bought the original plant and then have made divisions. Can anyone else help Rose out? — mss

  21. From Katy Central Texas:

    Will this Acanthus perform if kept in container? I have a place near a doorway I’d like to place it if it will do well in a large pot..and what size would be best. Can it be contained…or will it bust out the!

    I’ve never grown one in a container so I do not speak from experience. However, it doesn’t grow very fast so it should be feasible. It offsets, though. Seems to me that when it got a bit big you could just repot it and put the babies in their own pot. The biggest it’s gotten in the ground in Austin is about 3 feet wide and 2 1/2 feet tall. That’s because the heat cuts it down when it gets in the 90s. However, I’ve seen it much larger (4 or 5 feet) in San Francisco where the summers are cool. It’s comparable to a philodendron. — mss

  22. From shannon, charleston, sc:

    i have 3 acanthus in a nice shady spot in my backyard. 2 have “bloomed” and the other has a spike just beginning. my problem is that all of the leaves are turning yellow & falling off. any clue as to what’s going on?

  23. From Jackie, The Woodlands, TX:

    WOW! Thank goodness I found out what my plant is. We were landscaping new home and I bought a group of plants, several listed for shady areas. Hubby threw away the tag that told its name, and we’ve been trying to find out what it is since first of spring. We planted it under a clump of root bound trees. A flower spike began to grow in the middle of the beautiful green foliage and reached almost five feet. It is now middle of July and the leaves are just now turning yellow and the flower is dying. Our friends could not believe how beautiful it was. Until I read this web page I had no idea what to do with it and am glad I didn’t dig it up. We will keep watering (it requires a lot) and let it run its course by wilting, growing or whatever it desires. We love it and actually hope it will produce babies. So far I haven’t seen this happening but will let you know, that is if it returns in the fall or spring. Thanks for a great web site.

  24. From Irene Gordon South West France:

    HELP!! I’ve just bought 5 seeds. Thank goodness I have come across this discussion site as now I think I will place this magnificent looking plant in pots at the back of the bed.. I have enough problems with stubborn weeds spreading thru the flower bed without Acanthus Mollis stunning tho it may be.

  25. From Burgi, Seattle:

    I’ve had an acanthus in a large pot for 3 years now but it has not flowered yet. It also gets droopy in the hot sun and then some of the leaves wilt and/or get yellow. I love the leaf size and shape but not much else is happening here, although i’ve noticed it seems to have divided itself into 3 clumps. it sits on the deck where it gets sun for only a couple of hours and then mostly filtered but bright light. Any thoughts on why it won’t flower?

  26. From Cecilia (Carlsbad, San Diego - CA:

    Mesmerized by this acanthus mollis, bear’s breeches, oyster plant with great art history,I bought 20 divisions (flat rate box for 100.00)last fall, large and small and potted them all immediately. Amazing great immediate foliage growth in weeks – 100% success and the largest of the bunch had to grand spikes this spring….the two spikes are full of seeds and I expect the other 19 to produce next spring as they gain foliage ground this fall. I think I will resale them after reading this post and keep one or two in a large pot on a concrete slab so I don’t have the nightmare I am hearing through the text or plant them down a hillside that is neglected and native and see what happens maybe it will weed out the pampas grass, fennel and baby eucalyptus trees?
    I understand chemicals do not work…digging and throwing away the dirt is the only cure up to about 1.5-2 feet deep. Good Luck

  27. From Linda San Antonio:

    I really appreciate all of the hard work you put into your plant profiles.

    I spied acanthus mollis at a local nursery and finally bought one. Even though it’s winter, its a fairly thirsty plant. I’ll let it go dormant this summer.

  28. From Bitsy:

    I planted an acanthus mollis in a large container by our front door. Still in its first year, it took a little while to “catch fire” and then put out some beautiful tall leaves in the fall. The problem is that we had a cold snap in December and the plant was badly frost damaged. I had to remove the unsightly brown, collapsed, damaged foliage.

    Is it dead? Will it come back? I am worried that this apparently hardy plant was killed off.

    It lives in the Pacific Northwest, in a shady corner, in a large container (too large to be moved). I would appreciate any hopeful experiences…

    In cold winters or hot summers, my Acanthus mollis often dies back to the ground. So far it’s always comes back. I’m guessing yours will too. Don’t give up hope. — mss

  29. From vm (Austin, TX):

    I planted an acanthus mollis in a mostly shaded area at the entrance of my home. We have had it for 5+ years. It has grown into a large clump but I am not complaining it is very elegant. I like it so much just bought 2 more to use in another shady spot to cover foundation. It does wilt in the summer and I will trim away any yellowing leaves every couple of weeks in the heat of the summer – but if kept trimmed it still is worthy of sitting next to my doorway. In the hot Austin summer I try to water once maybe twice weekly -not bad. I love it. This winter it was full and gorgeous all winter (we had a pretty mild winter). It is not invasive but I have seen it bloom twice – maybe due to the shade. Just found the first pup this year and gave away to family. I am also looking for a variagated version to compliment the solid green leaves. Can’t find a seller yet – just pictures on the internet. I would recommend it for southern, hot, humid areas but keep it in mostly shaded areas.

  30. From Corrie (Baton Rouge, Louisiana):

    Thanks for the great information on this plant. I have one planted in partial/full sun. The leaves are very yellow and droppy. Now, I am thinking that I need to move it into an area with less sun in our hot climate (8b/9a). Just checking again to make sure you have not had any trouble with this plant being invasive in Austin. I just spent the last 5 years trying to rid my beds of running bamboo and asian jasmine. I do not want anything else I have to fight.

    Acanthus mollis is not invasive in Austin as our summers are too hot and dry for it. As soon as the temperatures hit the 90s it will die down until it is cooler. — mss

  31. From Libby, Los Angeles, CA:

    We planted 20 acanthus on a hillside covered with oaks, so they get a miz of sun and shade. While they have produced spectacular tall flowers, the leaves have never had the dark leafy foliage I have seen in other gardens nearby. My leaves look yellow and wilted, and they have been ravaged by snails (I recently tried a product called Sluggo that is not toxic to animals). The temperatures have not been that extreme yet at it is only early summer. Is water the antidote to watering or will they turn yellow no matter what? In addition, I have noticed lots of tiny bugs feasting on the flowers, but am not sure how to deal with them. Any suggestions for the yellow leaves and bugs?

  32. From Pamela, Campti, LA:

    Hmmm…I planted four acanthus this spring, in somewhat sandy soil–a couple of them put out new leaves, but as soon as it got up to 90 plus, they completely died down. Do you think the roots are still okay, waiting for cooler weather, or is it hopeless here? I have always wanted a clump of these, but didn’t realize they were so problematic in the heat–after all you see them in Greece all the time! If they don’t make it, I’m going to try one more time–but can’t seem to find a source for buying them (don’t want variegated or fancy–just the species). Any help and advice will be appreciated!

    That’s what they do. They’ll come back from their roots when it cools off. Mine are almost like a thermometer. I can tell when we hit 92° because that’s when they collapse. — mss

  33. From Bob, Ft. Worth, Texas:

    I bought an acanthus at the Ft. Worth Botanic Garden sale several years ago. The leaves were the attraction. Go to Rome. All the hills of Rome are covered with the plant. Simply everywhere. Mine, so far, is rather sedentary in that it hasn’t moved about. Let one of the blossom stalks mature and dry. Lovely thing, about three feet long. Makes a great, and very interesting dry flower arrangement. Seed pods about 3/8″ in diameter along the stalk. A section of the dry stalk is very suggestive of the top of a Corinthian column. My plant dies to ground at freeze, then comes on strong in early spring, blooms, stalks dry, spring leaves die away (now, late July) with strong fresh leaves coming out within and under them. Old leaves grew to 30+ inches. New leaves are making a cluster within clump of old leaves, which I will trim away in a month or so in order to expose new clump.
    My garden gets lots of visitors from garden clubs. All are astonished at the sight of this plant. I put mine in full shade, not because I was advised to, but because that was the place in which I wanted a large planting. Has done quite well there. In Rome (throughout Mediterranean as well?) they are everywhere from full shade to full sun. Seems to be treated as a weed there. All those pines of Rome have acanthus under them.

  34. From AnneMarie, the Netherlands:

    In my garden I planted 3 small accantus about 3 years ago.They grew so big that I have given 2 off them to my children.Each off them had about 10 flowers,very beautiful.I didn’t do anything spacial with
    them, they just grew and grew.
    One doesn’t see much off them overhere.
    Bye, bye.

    acantusses 3years
    ago, They grew so big that I gave 2 of them
    to my children, They have had about 10 flowers each, very beautiful, But they take too much room.
    Nothing special I did to them, they just grew and grew.

  35. From Andrew Lewis (Surrey UK):

    I have an Acanthus Mollis which has been growing in my garden,(Surrey in England),since I moved here some 11 years ago. It is very vigorous and produces some 14 spikes each year. Due to changes in my garden layout it now sits in the corner of my herb garden, hard up against a fence and the corner of my terrace. I have wanted to move it for some time but have been afraid of killing it. Some hope, judging by many of your comments. I have a cutting growing in a pot in case the transplant doesn’t work, but my concern now is that I will leave some root behind and will be plagued with a profusion of mini Acanthus for evermore. I have some Sodium Chlorate which is no longer available here in the UK. This kills just about everything but poisons the ground for at least a year and can damage other plants growing nearby. I could use Glyphosate which is systemic and can even get rid of bind weed which has the same root regenerative abilities that I have now learnt are a characteristic of Acanthus. Any suggestions concerning the relative merits of these two methods? Like the site. It’s very useful. Thanks.

    I have not used anything on my Acanthus mollis since Austin’s climate is enough to keep it in check. Of the two choices, I would try the least damaging one first. If you dig up the big plants, it’s likely that you will only have to poison any new smaller (and more vulnerable) plants that crop up later. — mss