Saturday, January 5, 2008

Paranoiac (Euphorbia trigona)

This is one of a series of plants I bought during a quest to get one particular plant. The plant I wanted was Euphorbia ammak; I wound up buying E. trigona and E. pseudocactus first, and then eventually got two enormous cuttings of the one I really wanted from someone on Garden Web.1

The nice surprise is that all three have turned out to be great additions to the group, though in different ways. Euphorbia trigona had one quirk that I haven't seen anyone else describe before, though, which was: it waited to see if I could be trusted before it started to grow. Or at least that's how it looked to me.

The original plant had both of these stems potted together; I divided them when I bought it and gave them each separate pots. And then for the next year, they just sat there. The taller of the two got a little taller (less than an inch, but enough to be detectable), and that was all. Then, suddenly, around September of this year, they started to branch, and they both got taller as well, and now I guess we're off to the races. Apparently they finally decided that I wasn't going to hurt them, or something like that.

There was one other odd moment with these. At some point last winter, they both started to get brown and tan patches in the center of the main stems, though only on one side:

I never figured out what started this, and I never figured out what to do to stop it. The plants just kind of quit on their own. My best guess is sunburn, which fits in some respects (the affected sides were the ones facing the window, and the brown started with a reddish color, like some plants get when they're sunburning) and not in others (this all happened in winter, the season without a lot of sun). I suppose if it starts up again this year, we'll have a theory.

This is not a difficult plant to keep, though there are some things to bear in mind if you're going to get one. First, they are a Euphorbia species,2 and as such, there's some dangerous sap involved. How dangerous? Hard to say. I have seen one account recently (in the comments) by a guy who says he got Euphorbia trigona sap in his eyes and was blind for two days as a result. Also there was apparently excruciating pain. There are also a number of accounts of people getting blisters when Euphorbia sap (not necessarily E. trigona) dripped on them, and occasional, impossible-to-verify reports of people having reactions just to breathing the air in the vicinity of a cut plant.3 I suspect that there's some hysteria and suggestibility involved here, and also that people may be getting different species mixed up, but even so, Euphorbias are not wholly benign and should be treated with a certain amount of respect and common sense. Eye protection, in particular, is probably a good idea: they squirt latex when cut often enough, and the consequences if you get some in your eye are severe enough, that taking the ten extra seconds to put on a pair of goggles (or wraparound sunglasses, even) is going to be worth it, on average, if you're going to prune one. The only other thing I do with Euphorbias is make sure to have some paper towels handy, if I'm going to be making a cut. I try to cover the side of the cut closest to me with the paper towel, so that if it should squirt latex in my direction, I won't get sap shot into my face. (It's also handy to have paper towels because sometimes they drip for a while after being cut.)

For less traumatic plant maintenance, like picking off dead leaves, or repotting, I personally don't go to any extra trouble to protect myself, but then, I don't react to Euphorbias particularly. Occasionally I get a little itchy.4 Even so, I wash pretty carefully after dealing with these plants for any length of time; my skin may be fine, but if I forget about the Euphorbia sap and rub my eyes, I'm screwed. So I wash anyway. Rubbing alcohol is said to be useful for dried sap, by the way, if you find some you'd forgotten about.

So, if you have pets or small children, this is probably not the plant for you: even setting the sap aside, there are still thorns, and the plant does tend to be top-heavy over time. This is not a good plant for high-traffic areas, for people with small children that might stick pieces of it in their mouths, for people with large pets that could knock it over, or for placing on tall stands.

Now that I've completely scared you away from ever wanting one of these, let's talk about how you would care for them if you were to get one, which you won't.

Light and watering are the primary things to watch here; there are Euphorbia pests, but they tend not to be a huge deal. (At one time, I thought that mine had had whitefly, but I'm doubting this in retrospect; mealybugs or scale are probably more likely and/or more damaging. Euphorbias in general are pretty hardy folk.) Most propagation is by cuttings – just lop off a piece, let it dry for a few days to a few weeks, and then plant it. Start watering when you see new growth. My impression is that cuttings rarely fail, but are slow enough that they can try one's patience: I have yet to see the Euphorbia ammak cuttings I mentioned earlier do anything, despite having had them for six months (on the other hand, a E. lactea cutting I took at work has rooted already, so there's some variation from species to species and situation to situation). And of course you do have to feed once in a while, but that's not really a big deal. Light and water are big.

Light: These don't necessarily have to have full sun, but they do need very bright light or they will become thin and weak. Drastically increasing light intensity can lead to problems: if you're going to bring an indoor plant outside, do so gradually, in steadily-increasing intensity and duration. If you just chuck it out into the middle of the front yard, it'll burn and burn and burn.

Water: Euphorbia trigona actually tends to be a pretty problem-free plant, when left to its own devices. As with any succulent, rot is a concern, but it's not inevitable. Drench the plant with water when the soil is almost completely dry, then allow it to dry out almost completely before watering it again. If a plant has begun to succumb to rot, cutting the rot away with a clean knife is more likely to work than trying to poison it away with a fungicide. On a large plant, one may be able to cut away the affected tissue with a clean knife, though this depends on where the problem is located and how widespread it has become. If the plant's base is completely gone, you can still take cuttings and root them, as described above.

There is at least one cultivar: I'm unclear on the name, but I've seen it labeled 'Red,' 'Royal Red,' or 'Rubra.' It is, as you would expect, red:

I haven't seen anything to suggest that it is any more or less difficult than the normal green variety. (UPDATE: I did eventually get one. They're not any more trouble than the green variety, though the red color will fade if the plant's not getting enough light.)

E. trigona is often confused with another commonly-sold Euphorbia, E. lactea. The confusion is understandable; the stems are remarkably similar. Once a plant has branched, though, it's easy enough to tell the difference: E. trigona branches, once sprouted, remain close to the original stem, and grow parallel to it. E. trigona also grows small leaves on new growth: the leaves form between the thorns. In E. lactea, on the other hand, branches grow out away from the main stem at an angle, and may or may not ever wind up vertical. The result is that E. lactea has a more open, treelike form, and is thus unpleasant to bump into from any angle, and takes up more space, pound for pound, so you're more likely to bump into it; E. trigona is harder to hurt yourself with, unless you ignore warning signs about a shifting center of gravity.

Euphorbia lactea

Finally: I would hope that nothing written here deters anybody from buying one of these plants, if that's what they want to buy. I figure it's important to get people's attention, so they have a safe amount of respect for the plant, but it's not like the plant is going to come after you in the middle of the night with a sawed-off shotgun. It's all common sense, really, I swear.


Photo credit: all mine.

1 Enormous to the point where I was a little concerned that people might think I was getting severed human arms in the mail. Apparently, either 1) nobody thought that, or 2) people send one another severed human arms all the time.
2 Also: Euphorbias are not cacti. Very few things will rile up a pedantic cactus and succulent collector quicker than calling a Euphorbia a cactus. A lot of them have spines like cacti, they come in the same shapes as cacti, they serve the same general function in their ecosystems as cacti, you can root cuttings of them like cacti, and they are virtually interchangeable with cacti in every other respect, but they are not. Cacti. What's the difference? Oy. How about we go back to the main text and let me tackle this some other time? Or, if you just can't wait to find out, you could read this: it's not inaccurate, though I think it fails to make some distinctions that need to be made. It was the best answer I could locate, though.
3 Particularly the species E. cooperi, which has a fearsome reputation, and gets mentioned often enough that one assumes people aren't just making up stories about it. E. tirucalli ("pencil cactus," or "Firesticks") also has a lot of stories out there, and I'm more careful with that one, too. E. trigona, our subject here, has a lot of warnings, but few actual stories about it causing damage or irritation, and it's pretty widely sold, so it's clearly not a total ninja like E. cooperi that can kill you seven different ways in the blink of an eye. So don't panic: just don't forget what you're working on, and that you need to be mindful of where the sap is going.
4 Though, for itchiness, nothing at work has been worse than picking dead and yellowing leaves out of Ficus benjamina trees, which I can literally only do for a couple minutes before I have to run screaming to the sink. I suspect this is at least partially psychological, since I'm beginning to itch right now as I type this, but even so: there's something about Ficus benjamina that makes me itchy even when I'm thinking about other things entirely. My current theory blames pesticide residue, since the same thing happens sometimes when I weed under the tables in the greenhouse.


Anonymous said...

I have never experienced any problems from my Euphorbia plants, but I am pretty cautious after reading scary accounts found at ""

In fact, at a plant exchange this fall, I had the opportunity to take a very large E. tirucalli and could not bring myself to grab it. (Now I am kicking myself though.)

also, just now as I was reading this blog entry, the clickable footnotes were not working right; when I clicked on them I was routed to another site!


mr_subjunctive said...

That was weird. Somehow or another, the footnotes and the editing page got attached to one another. Hopefully I got them working now.

Sarah Sedwick Studio said...

E. Trigona is my husband's favorite plant. He used to call ours our "relationship plant" ala "How to lose a guy in 10 days" (the movie - if you haven't seen it, it's cute, and in it, they have a 'love fern', very nice idea, though she's trying to annoy him with it in the script)

Back to the point: I used to have both E. Trigona and E. Lactea. Once my cat took a flying leap at Trigona and sliced off a chunk with his outstretched claw. Rooted very easily.

This plant does not need to go outside in summer. Mine never did, but it lived by a big window, and grew about six inches a year - only in the summer. In winter it didn't want water, and it didn't want to grow.

Great plant. Mr S - if you ever get the red variety, I'm sending my cat over to take cuttings!

mr_subjunctive said...

Hmm. Well, I don't think I would have thought of it as an especially romantic plant, but whatever works, I guess.

I agree that it's not necessary for the plant to go out in the summer; a lot of people like to do that for their plants, though.

My plant has been growing in winter, if slowly: it seemed to be making the fastest progress in about October. No idea what that's about.

If we get a small specimen of the red E. trigona sometime, I might buy one. It's a nice enough plant. For the moment, though, all we have is a big $50 one (pictured), which even with the employee discount is more money and space than I'm willing to spare. But I'll let you and the cat know.

Anonymous said...

That's a nice plant. I shall have to hunt for one when I make my pilgrimate to the world's best houseplant nursery this winter - thanks for the reminder! I used to have a client with great light who had tons of these, and I loved them.

I wonder if rubbing alcohol would work on poinsettia sap? I end up with that nasty brown/grey dried goo ("poinsettia blood") all over my arms in December, and it takes really rough scrubbing to get it all off. Thanks for the suggestion.

I read up on allergies to plants a while back. Ficus is a pretty common allergen - the latex in the sap, I think. I read about a guy with a bad allergy to spaths. My personal nemesis is yuccas - I get red welts on my hands and arms, but they go away within an hour. If I have to cut off many dried leaves, I get a really bad sneezing and runny nose attack that last for an hour or so too. I am allergic to dried flowers, so maybe it's the dried leaves and the dust rather than the plant itself. But the welts are definintely from touching the yucca.

mr_subjunctive said...

So far, I haven't had any of the symptoms of a full-blown allergy: with cats (and a few dogs) I develop asthma, my eyes itch and water, I sneeze, and my arms, especially the insides of my elbows (where there are often bad hives) itch like crazy. It's way less exciting with the Ficus, but it also happens consistently and often. Our bigger Ficus benjaminas are dropping a lot of leaves now, and I spend a lot of time trying to pull yellow leaves out of the center of big trees.

I just did a search and found this page at GW, with (ew!) pictures of someone's reaction to Ficus sap. I hope I never get to that point.

I don't react to Yucca, thank god ('cause I loves me my Yuccas), but I get welts like you describe from Agave sometimes, where it'll hurt and/or itch for an hour or two after getting poked with a spine. That hasn't been serious so far either, but it's obnoxious, because until it goes away I don't know whether something's broken off in the skin or not.

I had a very bad pesticide experience a month or so back where my nose ran and ran and ran for a good two or three hours after exposure -- as symptoms go, it wasn't that horrible, but it was freaky because it wouldn't stop, and I couldn't get anything done in the greenhouse because I was having to stop whatever I was doing every couple minutes so I could go blow my nose. I wound up leaving work early, and I didn't come in the next day, either, due to lingering respiratory problems. When the label says Use in a well-ventilated area, sometimes it's actually important to do so. Apparently.

It's the world's best houseplant nursery, but you're not going to tell us where it is? Oh, yeah, that's fair.

Anonymous said...

Oh yeah, I forgot to mention that I have the red Euphorbia,


Anonymous said...

Well, I don't know if it's really the world's best houseplant nursery. It's an enormous garden center in the DC suburbs that gets a huge selection of houseplants in January and February and has a sale on selected ones in February. Not cheap, but high quality, and stuff you simply can't find retail anywhere else in the area that I know about. The rest of the year, the seasonal plants take up a lot of room, but they still have a fair number of houseplants.

Anonymous said...

Used to have a Euphorbia for years, and it grew fantastically. The bare patches you mention appear to be harmless.
Euphorbia by definition are poisonous plants, and its sap (as you rightly say) should be treated with great caution.

Anonymous said...

What awesome information you have. (I can't wait to see what else I can "dig" up on your site.) All the info was very helpful for me to be able to identify my plant. It was given to me by my sister who was moving and did not want to move the Paranoiac. I have two kids (5 & 2) and 3 dogs... so I brought the plant to work where there are a ton of windows and it has been happy, until... a big piece of wood (decorative at the celing/top of window) fell down, due to it not being put in the way it should have been. Well, it got hurt. It is at least 4 feet tall and there are 2 big stalks that have different sized branches going verticle - it still is a good sized plant. So, because I like it so much I did a search of what was left of the little flag that tells all about the plant and how to care for it. The first line read: "Royal R.." Under that: "Euphorb..". So, I'm guessing it is the Red variety. But I was certain the the "leaves" were green, not red - after learing more about it I have looked more closely and the new growth at the top is a purple/red. So, I'm not sure if it is the green or red variaty.
Anyways, there is a good sized chunk off one of the sides - right on the edge, about 4 inches tall. It looks as if someone just snapped off the thorny edge. There were other places that got hurt, too, but not as bad. Also, a few of the larger branches were just hanging, so I snipped them off and they are just sitting there, drying out right now. (All this was done prior to me knowing the white sap is poisionus.) It has been 6 days now since the accident. Do you have any suggestions as to what I can do to help this plant recover?
Also, I have a question regarding the "lopping off" to get a new plant. Should you only do it where there are "branches", or can you cut off a top section? If you can take off a top section, what about the exposed area that is on the plant?
When my sister gave it to me, the info flag was whole and it said to keep it in a small pot, but you never mentioned anything about that... what is you opinion on that?

mr_subjunctive said...

The red varieties will turn green if they're not getting enough light; it's also possible that someone along the way put the wrong tag in the plant.

I don't think there's anything huge that needs to be done to help the plant repair itself: so long as you let it dry on its own, there shouldn't be a rot issue or anything.

You can cut a piece off straight across the stem whether there's a branch there or not. The parent plant will dry on its own without any problems; the cutting will need to dry also before planting.

Haven't heard anything about the small-pot issue, but it's probably not a bad idea; the succulent Euphorbias generally seem to have smaller root balls than you'd think from looking at the aboveground part.

Anonymous said...

Thank you. Another great feature to your site, you reply quickly, and thank you for that.

Now, in reply to your response, when I cut across the stem, what will happen to the mother stem? I understand it will dry, but will it have any growth from that spot?

I also forgot to mention earlier, this "sunburn" you've mentioned... One of my stalks has a bad spot, close to the base, maybe 3 inches from the soil and 2 inches tall. It is brown and white, and appears to have taken over most of the stalk in that section - not just on one side. (It was that way when my sister gave it to me, but I think it may be getting worse.) Should I cut the plant above and below that spot and start a new plant?

(Would you like to see pictures of it? Can I get them to you somehow? Since it is at work it would be a few days.)

I am also wondering about the leaves the Euphorbias produce. The pic of the red variety you have has a ton of leaves, where the green one doesn't have as many (like mine. Normally, not many and right now, it doesn't have any). So, what makes the leaves grow, or not grow? And, are they leaves, or flowers? If they are not flowers, does the Euphorbia flower?

Thank you - KD in NC

mr_subjunctive said...

Well, I don't always reply quickly. I happened to be on lunch break from work and saw your comment not too long after you posted it.

The mother stem will probably resprout eventually, though I don't know for sure how long it will take or where the new growth will happen. On E. ammak, new stems spring up from each rib of the original plant, and I think cacti are supposed to do that too, some of them, but I don't know specifically about E. trigona.

On the brown spot, I guess if it really bothers you that it's there, cutting it all off and using the green part for cuttings certainly isn't going to hurt anything. Not really necessary, though, if it's the same thing as what I have on mine.

The leaves really are leaves, and there really are flowers as well. The flowers look sort of like the Monadenium flowers did in this post, if I remember right. I don't think it's very common for a Euphorbia to flower in the home, though. Mine never have. I think I've seen a few here and there at work, but not trigona flowers.

The leaves are there when new growth appears, but then sometimes they hang around and sometimes they don't. There's always one leaf per pair of spines, all the way up. I'm not sure exactly what causes them to drop the leaves; I suspect they let go of them if the plant is too hot or the air is too dry, but I'm not sure about that: I just know that my plants at home don't keep them forever, and it doesn't seem to matter any to the plant.

Anonymous said...

I've had mine for over 30 years and have started dozen of plants for friends and family. Mine seems to grow about a foot a year. I leave it by a large west facing window year 'round. Mostly because it is too large to move, but also because it would get sunburned when I moved it outside; even to a shaddy area. I don't let my cuttings dry for a couple days. I cut and plant at the same time. Thanks for the nice pictures my friend and I were trying to identify the plant so she could enter hers in the county fair.

Anonymous said...

I googled cactus with leaves and found this blog by Mr. S. Now I know what I have. El Cacti Grande was about 8" when I got him and he sits in a pot at my workshop. Nothing happened for quite awhile, and I was told NOT to water it till I saw some growth. OMG, it's about 15" now with the new growth and has large leaves all the way up. He's quite the handsome fella.


I enjoyed your Euphorbia story. Ive been growing them for more than 30 years. I avoid the sap but dont worry about it. A dilute 25% alcohol/water solution with squirt of dishwashing liquid takes care of that and most bugs too. Take cuttings in spring or early summer. Cut at joint or narrowest part of stem. For top heavy plant,place in next size pot to double base weight. Also reduces evaporation in sun where I grow mine, May thru sometime in Oct. Many of my Euphorbs are blooming now. Crown of thorns blooms all year. Check out Euphobia nerifolia for nicely branching shrub sized specimen. Has great varigation on stems like E. ammak.

Anne said...

Thank you for your plant pages!

We got our E. trigona from a friend who was moving to Australia. It's a Red and came to us in horrible condition. He had neglected it and when it came to our house it was slumped over, forming an arch, and the leaves were falling off in the wind.

We didn't know what it was, as our friend had long forgotten the name, so we weren't sure how to help it. We just propped it up with stakes the best we could and kept it that way for several months (it was about 3 feet tall). It would grow new leaves but they would quickly fall.

We hacked it in half this spring and cut the weak part off from the middle/arch. We let the top half dry for a while before planting it.

Both have seemed to survive and have sprouted new leaves and the bottom half even has a new branch!

I'm hoping it's making a good, slow recovery, because I rather like it's look.

Jane said...

I also Googled "cactus with leaves" and found your blog ... how informative! I got three cuttings from a friend's Euphorbia trigona about a year and a half ago, and stuck them all in one pot. They presented a rather, ummm, phallic appearance as they got taller and taller without doing much else ... then suddenly, about six months ago, they began branching like crazy. The darn thing tipped over last week; I hadn't realized how top-heavy it had become. A pair of oven mitts were pressed into service as I repotted the plant into a larger and deeper container; it isn't going over again anytime soon! Apparently it is very happy in my northwest-facing window, because it is full of leaves. Another friend who received a cutting from the same plant just has one tall, bare stalk. The friend with the original plant offered more cuttings this year, but I just don't have any more windowsill real estate left (especially since I now have a cat, and one section on each sill must be left open for his lounging pleasure). He doesn't bother the plants, by the way ... wise cat!

mr_subjunctive said...

The plants in the first picture did finally decide to start branching, though I had to move them to bigger pots first (it's unclear how much of a cause-effect relationship there was between the growing and the repotting). I'm sort of in the process of trying to get pictures. But so that does really happen, if you wait for it long enough.

I also finally acquired a 'Red,' which is so far five totally unbranched plants in a six-inch pot. Not a big deal in itself, but the tallest of the five is now over three feet tall, and is just millimeters away from outgrowing its shelf. Don't know what I'm going to do when that happens; I don't want to cut it back.

They've all kept the habit of doing most of their growth in the fall. For what it's worth to anybody.

Anonymous said...

I have the Euphorbia Trigona. Got it about 4 years ago. It's my favorite plant (not cactus you say?). It faces west and grows about a foot a year maybe a little more. It's really branching out and some of the arms look like they are getting kind-of heavy for it. I don't want to bother it but its starting to look a little uncomfortable. Thanks for the tips on cuttings. Its also nice to know the real name finally.

cirrat said...

All right, this is it. Done with the year 2007 and looking forward to the next :) I really like your blog

wool and misc said...

this is extremely helpful, thanks! about a week after i bought my plant from lowe's garden center, i found that the tips of the royal red were turning light green. do you think it's not getting enough light indoors? thanks!!

mr_subjunctive said...

wool and misc:

Most likely. It may be reacting to not getting enough light when it was in the store, though, and not what you're doing in your home. Sometimes plants have delayed reactions like that. Whatever the cause, the red will come back when it's getting enough light again.

Anonymous said...

My E. Trigona of 15 years ish, has rotted at the root giving a thinning black stem. The tops are still green so I have cut them at points where the stem seems OK and will plant the cuttings as published. You suggest leaving the cuttings for afew days to a week. Should they be kept in a particular environment? i.e. cool/shaded/... or doesn't it matter? Greenhouse extremely hot at the moment. Will see if they think I'm not trying to hurt them!

mr_subjunctive said...


I'm not sure whether it actually matters, but I would look for a moderate-temperature spot with bright indirect light, like an unobstructed north-facing windowsill or something like that, if it were me.

Also, the stems will try to bend toward the light, even when unconnected to a plant, so if you're going to have them drying on a table or something, rotate them every so often. Otherwise they'll become sort of U-shaped, which will be C-shaped when you go to plant them.

Flavio said...

I have grown Euphorbia Trigonas since 2000, and never had any problem. I notice that leaving them inside the house, near the window is an excellent spot, preferable if receiving morning sunlight. When light is not adequate branches and the main stem start deforming, instead of growing straightly. They are beautiful and should be kept in
good looking pots. I love to photograph E/Trigonas.

Joe C. said...

I was given 3 three inch long (about 1 inch wide) cuttings from Euphorbia trigona over 10 years ago. They have been doing well. After a few months of doing nothing, they are now 3 to 4 feet tall with many branches.

The original plant from which the cuttings were taken was about 4 inches wide at the base, whereas my plants are all still about 1 inch wide.

Is it possible to encourage these plants to grow wider? Or is there something that one should do at the start to create a wider plant base/stem/stalk?


mr_subjunctive said...

Joe C.:

I don't know of anything specific, no. I noticed my plants' stems getting thicker after I repotted them a while ago (not sure how long ago it was), but that's not a very compelling argument for repotting being the answer.

The 'Red' variety of Euphorbia trigona I have has five stems potted together into a single 6" or 8" (forget which) pot, and none of them have thicker bases. Branches, either, as far as that goes. I suppose it's possible that if your plants are all potted together in a single pot, they could be crowding one another, or somehow inhibiting the development of a thicker base.

Either way, I'm just guessing, and even if it's a good guess, I'd wait until April or May to repot. Cold, plus the soil drying out more slowly because there's more of it there, would more likely lead to rot. E. trigonas are, in my experience, pretty tough plants, and aren't especially rot-prone, but a ten-year-old plant isn't one I'd gamble with, if it were me.

Unknown said...

My Euphorbia T is over seven feet tall and 2-3 feet wide at the top. It is the offspring of one I had, and sold in a moving auction, four years ago. I gave them both the name Desert Pete, and Pete Sr. was just as huge when he left. I am currently considering selling (or even giving "Jr." away because of the hassle of moving him in & out of the house twice a year which involves a moving dolly, a shower curtain and THICK gloves - VERY heavy and VERY cumbersome. Trouble is, I will probably keep a "baby" and have the same problem in 4 more years. This puppy LOVES to grow ! ! !

Pat M. said...

Thanks for some excellent information. I was given a E. trigona in 1978 and I still have its cutting offspring. I have found the information in this blog to be exceptionally accurate when compared to my personal experiences. Thanks for the "reminder" information as I get ready to take more cuttings this spring and add to my E. trigona forest.

Unknown said...

Hi there,

Thanks for your informative blog post about this plant. I was looking for some toxicology information because my cat just ate one of the leaves from it. I saw that the sap can cause an allergic reaction, but what about the leaves? I'm keeping an eye on him and he seems fine but I'm a little scared. Thanks for any help you can offer.

mr_subjunctive said...


My impression is that E. trigona is less toxic than the average Euphorbia, and a single leaf isn't very much. I am not a veterinarian, but I think the most likely thing to happen in this case is either 1) nothing or 2) vomiting and/or diarrhea.

Jenn said...

(this all happened in winter, the season without a lot of sun)

Ah, but in winter the angle of the light changes... was this close enough to a window that the sun may have touched it?

mr_subjunctive said...


Possibly? It was a long time ago.

My memory of the arrangement is that they spent most of their time on the topmost shelf, so even if the sunlight slanted in better in the winter, it still wouldn't have hit most of the plant. The arrangement changed, though, fairly often, and I can't be sure that the configuration I'm remembering is the one that was typical.

Also, even if it was getting more direct sun geometrically speaking, in practice it's cloudier in the winter, and day length is shorter, so the intensity shouldn't have been enough to do that. And anyway, they're desert plants; they should be able to take some sun, especially if it comes on gradually, like the change of seasons would.

Whatever it was, it hasn't happened again. I had the thought while writing this that maybe edema might explain it, though from what I recall of the setup, edema should have been less likely in the apartment (warmer, drier soil) than it is here (colder, soil that stays wet longer).

So, [shrug]. It's a mystery.

katie said...

I just purchased a 9" tall speciman of E. Trigona @ the Desert plant sale - University of Texas @ El Paso. Your blog was important to my research on how to care for the varieties of plants I purchased there. It is red and beautiful - the stalk - you may have a more accurate name for the main body of the plant. It is a deep crimson color and after initially reading your blog I thought it had been caught in the nick-of-time from a sunburn scorching. Now I believe it may be the red variety. It's new growth is green however, so I may need to move it out of the bathroom where it receives light from an indirect sun source in the ceiling. Thank-you for your knowledgeable assistance in caring, and safe-handling of this very beautiful plant. I have a picture of it, and wonder @ what heighth would it be safe to take cuttings.

mr_subjunctive said...


I agree that it's probably the red variety, and that the new growth is probably green because it's not getting as much light as it was wherever it was being grown before you got it.

I'm not sure I could come up with a firm rule about when to take cuttings; if it's branching already, I think you're probably safe to cut off one of the branches and root it. If not, I'd wait until it is (it'd probably root either way, but the plant will look better if it has a small scar from removing a branch than it would from being cut off at the top).

Anonymous said...

Many thanx for such an informative blog! I've had my E.Trigona for several years now. Last year we moved & I now hv it on an east-facing window. It must luv it there as it's branching like crazy!! I'm concerned about it becoming too top-heavy, but not ready to repot it, so will take cuttings which should make great Christmas gifts.=) Many thanx again for all the invaluable info! =)

Anonymous said...

My plant has really entertained me. Almost see new growth overnight.However recently many of my
stalks have become limp and are bending over. Any suggestions?

mr_subjunctive said...


Well, they're not supposed to bend over. My guess is that your plant is rotting, but A) that's only a guess and B) if I'm right, there isn't much you can do about it except try to take a cutting from an uninfected piece and start over.

You might try posting a picture to the UBC Indoor Plant Forum, or sending one to Cactus Blog, in hopes of finding someone with more direct experience about this problem than I have.

Anonymous said...

We got a 6 1/2 ft tall Euphorbia T. for free. They said nothing about the danger of it and didn't help us load it.After getting it home, cleaning up the rocks by hand that fell out of the pot, tidied up the dirt from it etc, we were happy about our score! Well, within 15 minutes, my Husband's eyes felt dry and itchy so he put some Visine in them then SCREAMED like a child. His eyes were SO RED,WEEPING,BURNING,EXTREMELY SORE that we got scared enough to call Poison Control!!! She said to try to flush with water etc for 20 minutes then to go to the Hospital because it didn't help what so ever!She wait the people should be contacted. They should have warned us about what would happen and relay the danger.The poison control people did that for us...we took off to the Hospital where they flushed out his eyes (which he could barely see out of) and gave him drugs for the pain and swelling. He missed 2 days of work because of his vision being blurred and his eyes/lids being swollen and sensitive. The dust particles from the pot of rocks & dirt combined with being so close up to it caused the severe reaction. The plant will be buried when it dies off.

johnny said...

I live in sub-tropical Australia. I started collecting bromeliads 5 years ago but have got bored with those and started collecting Euphorbias. I have quite a few and buy mainly at our local flea markets. I love unusual things so these fit my fetishes. I tend to be a little slack so have had much of the latex sap on my hands but i have not had any issues with skin problems. Some people are extremely sensitive to plant products of any type, even sitting on the grass is painful for some.

Anonymous said...

I had a Euphorbia trigona for 18 years..I received it as a Mother's Day was about 12 inches tall at the time and when it was 7 feet tall and I cried my eyes out. Loved that plant and I am thinking of getting another one if I can find one.

mr_subjunctive said...


I might know a place that has them.

Steve Asbell said...

As always, thanks for the informative post. I just got one (E. trigona 'Royal Red') myself and have planted it with a Dyckia and some variegated portulacaria... Yes, repotting will be a pain when they grow up but it's worth it!

Labor Left Manifesto said...

I was driving home Tuesday when I passed an apartment with a pile of junk out at the curb. And there was this huge 7 ½ foot tall “cactus” leaning against a broken desk. I drove past three times and finally stopped. The apartment owner said the former tenants left it there and the new people wanted it out, so he gently moved it to the curb. I couldn’t just leave the old guy out there to be picked up by the trash people. So he helped me get it into the truck.

Madison is a college town and we call moving day "hippy Christmas."

Anyway, a couple of hours of web search identified it as e. trigona and that led me to your excellent page. After reading through though, it looks like I’ll have to cut a hole in the ceiling by next spring. And maybe I know why my eyes got all red and itchy after carrying it up the stairs.

Thanks for what you do.

Unknown said...

I've had this plant for about 15 years...and never knew what it was! It does happily sit on a little corner counter in my kitchen, in front of a north-facing window, and require next to nothing from me. I just discovered the milky white sap, when I accidentally knocked off an arm....I immediately thought of "Gopher Purge", so took precautions to not contact the sap. Have never had any symptoms that I could even remotely attribute to this plant. But then, as I said...I really don't do much with it.
That being I approach retirement age, and consider moving on from our current hacienda, to a much smaller one, on wheels, (and hopefully with a diesel pusher!)I will be looking for homes for some of my larger house plants. If anyone reading this is desiring a new house-baby, and happens to live near, or travel through, NE Washington state, I'd be open to sending this on it's own little adventure.

Barry Wood said...

Thanks for the information. I was given a massive E. trigona about 15 years ago by an elderly friend who was moving to Texas. He didn't know what it was exactly; just called it a "cactus." I didn't know that it was not at all hardy (I have prickly pear cacti that I leave outside all winter, here in Northern Virginia). Thus I killed it by leaving it exposed to the frost. However, I had taken a couple of small cuttings from it - pieces that had fallen off, actually. These had rooted easily and are still with me; now three and five feet high, respectively. I didn't know about the poisonous sap. Wondering if I can use it to get rid of an exceedingly bothersome infestation of chipmunks. They are eating my tulip bulbs by the dozens if not hundreds.

Anonymous said...

I have a Trigona that is now, including tallish pot, 2.62 meters tall and only 80mm off my ceiling. I will need to move it or dispose of it to someone with a loftier ceiling. I also contemplate moving it outside but I'm uncertain if it would survive the wind and winter cold (Wellington New Zealand).

Barry Wood said...

Anonymous -- Why not just cut the top couple of feet off of the Trigona? You could make some cuttings out of that and create some babies to give away. Pieces about five or six inches long work well for me. Taking it outside is fine if you never get freezing temperatures, but apparently frosts are not unknown in Wellington so I might not chance it.

Johnny & Crystal said...


My girlfriend and I are trying to save are poor large cactus plant which we believe to be a
Paranoiac (Euphorbia trigona) like the ones talked about here.

We've been trying to save it for quite some time now.
We adopted it from someone we met that was moving, and brought home into our apartment.
It gets less sun than it did with it's previous plant family now and we also re-potted it when we brought the big one here. It stands about 6ft tall and is in a 14"x14" pot with a with mix of rocks and organic soil.
It looks like it dying, it's very skinny, sucked in on itself. It seems almost hollow.
We give it about a cup of water a month. Is it thirsty or over watered?
We also recently moved it into a slightly more sunny spot of our home which is still not in direct sun but gets a nice glow through the day. It only seems to be doing worse if any different at all. Too little sun, or too much?

We recently got some organic cactus soil and were about to re-pot it with a mix of this new stuff and it's old but before we did we are seeking some experts with this sort of plant dilemma's advice.

Someone please help us, we don't want to lose it. We are plant people, our plants and our animals are our lives. We can send pics as well.
Thanks alot!
- Johnny & Crystal

mr_subjunctive said...

Johnny & Crystal:

Pics would probably help -- and feel free to send some -- but I doubt that the light is your problem.

My bet would be that it's probably a watering issue of some kind, that either the "organic soil" is retaining water too long because it's too heavy and water-retentive (I don't suppose you have a brand/product name for the soil? Or the ingredients list? Do you recall whether it said it was appropriate for houseplants or container plants? Which BTW definitely tell me what the new organic cactus soil says is in it when you reply.), or the soil is fine and a cup of water per month is not enough.

I have a couple plants that aren't as big as yours -- about 4 feet tall, in 10-inch pots -- and I give them a good soaking every 4-6 weeks, completely saturating the soil, then allowing it to drain. I don't know exactly how much water this amounts to, but it's way the hell more than a cup. This doesn't necessarily mean that you're underwatering, since temperature, humidity, light, pot size, pot composition, and soil composition all influence the rate at which a plant dries out, but it seems to me like it's more likely to be under than over.

That the stems are shriveled also suggests that probably it's chronically dry; it may in fact be too late to do anything other than try to take cuttings, if it's already as far gone as you describe. Photos would be more conclusive. Ideally, I'd want in-focus pictures of: a wide view of the whole plant and pot, a close-up of the base of the trunk and the soil it's in, a typical shriveled stem, and the growing tips at the top of the plant.

I really doubt that the change in location has hurt the plant any. I wouldn't change the soil until/unless you're pretty sure that the soil is the problem.

Do you remember anything about the root ball when you repotted it after you got it? Was the plant really rootbound (roots wound tightly around, just inside the container), or did you not see many roots at all?

Has it been producing new growth since you've had it?

How long ago did you get it / how long ago did it start shriveling?

Johnny & Crystal: said...

Hello, thanks so much for all the advice mr_subjunctive!

I'm going to try and send you pictures on your blog.

My girlfriend corrected me - it's more like 3 cups of water once a month. The soil we transferred it into initially had a small amount of stones at the base of the pot for drainage, and was a mix of the soil that was in the pot it came in with fresh organic potting soil for indoor plants - likely Happy Frog or something similar though I can't say for sure what the ingredients were.

The unopened bag of soil we have is from Organic Mechanics and specifically "cactus & succulent blend." Ingredients are: biochar, expanded shale, rice hulls, compost, worm castings and coconut husk fiber. Also contains the active ingredient sand (10%).

Pretty sure the root ball did not have many/any visible roots sticking out of the ball, nothing visible that I can call to mind at least, as far as branched-out roots.

We noticed a shriveling maybe about 1 1/2-2 months after we took the plant in last summer. We tried moving it from indirect light to an area that had slightly more sun, but to no avail. It slowly withered over time, progressing further as the year has passed up to this state we're at, with it seeming to fare even worse as we moved it right in front of the sunniest window (SE-facing), hoping that would help.

I don't think any new growth has happened, maybe some little phalange-type guys that stick off the main branches (you know, the little fingers?) but those are all shriveled up now. It also hasn't had any pieces fall off of it (yet) either.

Please have a look at the pics I'll be posting and let me know what you think. The soil seems dry now. Do you think we should really try soaking it, giving it a week or so and then giving it a little more water and watching it for the month? Or try the new soil maybe? I really hope we can save it!

Thanks again so very much for all your help and we are emailing you some pics right now.

mr_subjunctive said...

Johnny & Crystal (part 1 of 2):

Okay, so, I'm going to preface this by saying that your situation is different enough from what I've dealt with before that I'm not particularly confident in my diagnosis (I'm, like, about 65% confident), and won't make any promises about my suggestions working.

I would also advise you to take at least one cutting of the plant (a single unbranched section of stem about 6 inches long, which has not flopped over: let it sit and dry out for like three days and then plant it in a 4-inch clay pot, water in, and then water thoroughly when the soil is completely dry), if the plant has sentimental value, as insurance in case things go badly with the parent plant. Because they might.

Branches that have shriveled and flopped over won't re-inflate themselves if things turn around later, so you may as well cut them off now too.

The problem with your main symptom, the branches shriveling and then flopping over, is that it tells you that the ends of the branches aren't receiving enough water, but it doesn't tell you why, and the possible reasons for that are contradictory. Plants can have a tough time taking up water if the soil is too wet, if the roots are rotting (usually also because the soil is too wet), or if there's not enough water going into the pot. So you're probably either keeping it too wet or too dry.

I'm aware of soil mixes like the one you're using, but I don't use them myself, so I don't have direct experience that would tell me how well they hold water. I'm not a fan of using compost in container plant mixes, because the size of the individual particles in the mix is often small enough to compact around the roots and rot them, and the soil that's in the pot already looks fine (as far as I can tell from a photo), so I would advise against repotting now.

(Generally speaking, there are two times when you want to change pots on a plant: when it's become so rootbound that it's no longer growing well and/or needs water all the time, in which case you want to move up a size, or when it's too wet, and the roots are rotting, in which case you want to go down a size. I don't think either case applies to your situation, and repotting can damage roots and set back plant growth, which you don't want to do to a plant that's already stressed.)

mr_subjunctive said...

Johnny & Crystal (part 2 of 2):

I think your problem is that you're not putting enough water in in the first place. I would advise you to start checking the plant every week or two: stick a finger into the soil as far as you can. Feel anything wet? Then it's not time to water yet. No moisture at all? Try going in a little bit further, by sticking a pencil in, angling it towards the center of the root ball. If the pencil also comes out dry, then take it to a shower and soak the hell out of the soil. No such thing as too much water here: you want to make sure that the whole rootball is completely wet, and then let it drain. (Usually I let my plants drain for 10-15 minutes, but that's a big pot, so you might want to make it sit in the shower for 25-30 just to be sure.) Then put it back in its regular spot, which should be as bright and warm as you can manage given your house/apartment/whatever, and start checking it every week or two again. It will dry out faster at some times of year than others, so ALWAYS make sure it's actually dry before you water; watering on a schedule will kill most plants sooner or later. Most likely, you'll wind up watering something like once every 6-10 weeks, but there's no substitute for actually checking the soil.

Also I acknowledge that transporting a plant that big, top-heavy, and pointy in and out of a shower five to nine times a year is going to be something of an ordeal and you're not going to like doing it. Sorry. (You're doing it that way because it's the only way to be sure that the water's gotten to every part of the root ball. I suppose you could also stick the pot in a wide bucket and keep dumping water in the pot until you see it coming out into the bucket, let it sit like that for five minutes to soak up some of the water, and then start pulling the excess water out with a turkey baster so you can dump it. Which I have in fact done for some of my more awkwardly-sized plants, though it's not that much of an improvement over carrying them to the shower, truth be told.)

Things to watch for:

• New growth is a good sign.
• Branches going black is a bad sign (it probably means that the roots are rotting, in which case you can either blame me for giving you terrible advice or blame the producer of the potting soil you used for making overly water-retentive soil: your choice).

The photos were a lot less dire-looking than what I was picturing in my head, so I think there's reason to be optimistic here.

Succulent Rookie said...

Hello. My brother gave me a cutting of an Euphorbia trigona that has been sitting in a glass of water for some time. The cutting has many roots. The base of the cutting is very brown but top top of the 9 inch cutting is green and looks fairly healthy. I don't know if I should plant it as-is or cut off the brown section (which includes the roots) and set it aside before planting the green section. Any advice would be appreciated.

mr_subjunctive said...

Succulent Rookie:

Are the roots healthy-looking? (i.e., not brown, don't fall apart if moved or touched, don't make the water smell bad, visibly getting longer over time)

I've never tried to start E. trigona cuttings in water, so I don't know how likely it is to work. In the absence of other information, I'd say:

1) if it's more of a tan brown than a dark brown, it's possibly just the natural corkiness of the stem, in which case go ahead and plant.
2) if the roots are continuing to grow, not smelly, not falling apart, and white, go ahead and plant.
3) if the stem is soft enough to give when pressed, or bends over when unsupported, cut off the green part and try starting over (let the cut dry for a couple days, then plant in potting soil and keep in a bright, warm place).
• if the above three things give you conflicting advice, make your decision based on #3.

Succulent Rookie said...

Thank you for your response. I have a picture but don't know how to attach it here. The entire stem is nice and firm. The roots are mostly brown but do not have an odor and they look strong not rotten. I'm thinking to plant it and wait to see how it responds. I was afraid that the brownish area was some sort of fungus or something like that.

Anne said...

Found this post so very helpful! Thx!!

Anonymous said...

Hi there! Just wanted to drop by and say thanks for this post. My friend recently gave me a Euphorbia that she'd propagated from a cutting (I'm assuming) and so it initially looked like a cactus because it only had very small and barely noticeable leaves and mostly had spines. A few weeks later it started sprouting and then the leaves just started getting bigger and bigger! Needless to say, I was concerned. I found your post though, so now I am enlightened ^-^ Thanks again and hope you keep writing awesome content!

Anonymous said...

Great Scott, what an excellent post and thread on this crazy plant. A friend of my wife’s gave us a little stalk (which we dutifully did what she told us to; wrap it in newspaper and set it in a closet for a couple of weeks, and then stick it in a pot) in I’d say about 1985. It topped out in 2014 when we moved houses in town and found the thing to be almost literally unmovable (about 8’ tall, 3’ dia, many hundreds of stalks, and of course, suffering no fools lightly) and was largely abandoned in our new yard while we dealt with a year-long major down-size and remodel. But I snagged a few nice cuttings and started over, and it’s now about 4’ tall and cranking. Indestructible. Certainly one of my favorite plants we’ve kept all these many years, along with a ~ 125 lb Philodendron solloum. Anyhow, the Euphorbium got moved in the house this morning for the first time in a couple of years, prompting a bit of googling, etc. Again, thx for the excellent post.

Dakota said...

Hi there,

My Euphorbia's leaves have all turned pale yellowand are slowly falling off. Is this a seasonal occurence? Or might there be light/water mishaps. I let it get just a tad more moist than bone dry according to my moisture meter, and it sits in a southeast corner. I am unsure what the issues are so i am seeking expert input.

Please help,


mr_subjunctive said...


It's normal for them to drop the leaves from time to time. I haven't figured out what causes it to happen -- it doesn't seem to be seasonal exactly -- but it doesn't necessarily mean that anything's wrong.

Unknown said...

I have a euphorbia 'red' and it is currently 4'3" tall. The top had a beautiful set of red leaves and the bottom has and off shoot branch with red leaves. I am wanting to propagate by cutting this into 3 pieces at the mid section but am a bit apprehensive as I don't want to end up killing the entire thing. Do you think this is a good idea? Question also...what is the lowest temperature the euphorbia would survive outside during the winter? Temps here are mid 30's to high 40's. *Wish I could provide a pic of my euphorbia 'red'.

mr_subjunctive said...


I hesitate to name a number for coldest temperature, because

• I don't have any direct personal experience keeping E. trigona outside in the cold,
• the coldest temperature a plant could survive depends partly on how healthy it is generally, how wet the soil is, whether it's been inside or outside before the cold hits, whether temperatures have been declining slowly over a long period or there's a sudden sharp drop, etc., so even if the species *can* survive a given temperature, it wouldn't guarantee that your particular specimen would, and
• on-line reference sources are all over the place on stuff like this, and it's difficult to tell just by looking who knows what they're talking about and who doesn't.

Davesgarden claims that they can be grown outdoors in USDA zone 9b (minimum air temperatures of -4C / 25F), but one of the comments says that brief exposure to temperatures below 0C / 32F will kill it. says 10C / 50F. Wikipedia says brief exposure to -3 is okay but neglects to say whether that's Fahrenheit or Celsius. The lowest temperature mine have ever been exposed to is somewhere around 10-13C / 50-55F, and I personally wouldn't risk going below that unless I had a spare plant to serve as a backup, but then I tend to be cautious about that sort of thing.

As far as the cutting-taking goes, I'm not sure I have the clearest mental picture of your plant. You're wanting to divide the side branch into three pieces?

If so, that's probably doable, though my personal inclination is to wait for side branches to start, let them get about 3 or 4 inches (8-10 cm) long (long enough for the stems to become triangular instead of flat), and then cut at the base of the new branch. The main advantage is that the scar from the branch being cut is less obvious that way. If you have a single long branch that you're dividing into three pieces, two of the three pieces will have a flat top from where they were cut. Over time, that will become less obvious, as new branches pop up around the cut stem, but it's not going to look as nice initially, and there's no guarantee that the new branches will come up symmetrically.

Whatever way you end up doing it, I'll caution you that cuttings are even worse about being top-heavy or developing leans to one side or another than full-grown plants are, so not only should you be very careful to make sure that the cuttings are *exactly* vertical, you should check them every so often to make sure that they're staying vertical. I repotted the plants in this post a long time ago and then stuck them outside, where the wind got strong enough to nudge them slightly to one side, and now I have two gigantic plants that are about 10 degrees off vertical and have a center of gravity outside and to the side of the pot. I can barely pick them up to water them without dumping them on the floor, or having five feet of spiny stems fall directly into my face. A much smaller cutting of those plants, that's never even been outside, has the same problem, because it started to tilt and I didn't correct it fast enough.