HiYa, Greetings from Germany. We are looking for an expert advice and hope you might be able to help. Our Euphorbia has on the bottom of the main stem a blackish discoloration. It is not soft or in anyway different texture from the rest of the cacti 🌵. We just worried it is some kind of rot. Do you know how best to proceed? Leave it for now or cut it and replant?
It looks like the start of rot. The soil looks too rich for the Euphorbia, so it may be taking too long to dry out after watering. You can use a systemic fungicide now and wait to see if it gets worse, or you can take the cuttings now to be sure. I recommend cutting just above the first branch, and taking that branch as a separate cutting. Spray with Hydrogen peroxide to help the ends heal, dust with Sulfur Dust. Wait a week and then plant into new fresh fast draining cactus soil. Be careful with the milky white latex sap as it is caustic and you do not want it near your eyes or lips.
I live in kansas city and was gifted this beauty for mothers day.. I want to take the best care possible of this gorgeous cactus! Our home has tons of natural light and we were told by the nursery we purchased it from that the spot we have it in is a good one even though it doesn’t received direct sun. I’m terrified of under/over watering. With a plant this size, how often should I be watering , and when I do, how much should I give? Do I fertilize? It’s about 8 ft tall. Thank you for your expertise.. Love your blog!
That’s quite large! In general I would recommend some direcgt sun, though these Euphorbias can sometimes handle a bright room with no direct light, but it’s tricky.
Basically, with lower light levels you want to water less. A lot less. I would try starting with watering every 2 months – try to soak the soil as much as possible without the plant sitting in water. I would fertilize just a little bit once per year in the spring. You want to slow down its growth so it doesn’t grow more than 2 or 3 inches in a year.
However it would be best if you can move it to where it gets some directct sun and then you can water more often.
Thank u Peter for responding so quickly. I must admit i am sort of surprised that you wouldn’t have a market for such a handsome looking guy but there you go.
alright thanks again maybe you’ll see it someday sitting on the street corner forlorn, unwatered and untouched by neither human nor dog wandering by. Give It a fond glance wontcha?
And what got Barbara to get poetic on us? Why this particular Euphorbia tirucalli right here:
Barbara asked if we wanted it since she has new grandkids and the plant is pretty poisonous, and we declined to take on this 5ft. tall x 4ft wide Euphorbia, attractive as it is. If anyone else local wants a referral to Barbara for this plant, let me know and I’ll pass along your information. Hopefully together we can forestall a “forlorn, unwatered and untouched” Firesticks.
Hello! I’m writing you from the Netherlands. I was looking for a Dutch website that could help me out with my problem, but there doesn’t seem to be any. I landed on your very helpful site, so I very much hope that you can help me out.
I have a ammak since my birthday last August. It used to be standing in a light room, with no direct sunlight. After a while I started seeing green “fresh” looking tops arriving and took that as a good sign: that cactus seemed happy. (I must admit, I don’t know anything about cactus plants). I haven’t given it any water.
Recently I moved to another place. Bringing the cactus with us in the truck must not have been fun for him. It was a bumpy ride. Once it got to the new house, it was moved around a little bit and ended up behind some boxes in order to protect it. The house was freshly painted and smelled horrible (chemical) for weeks. It still does a bit.
Meanwhile. The ammak seemed to do fine, but after not paying too much attention to it for about a week, today, I suddenly noticed that a couple of his arms are turning brown!!!!
I’m soooo scared that something horrible is going on with him!
It seems that these cactus plants get “rot”, but as far a I can tell, that normally starts from the bottom. In this case, the discolouration mostly affects his arms and also his leg a bit, but there on the leg, there are mainly brown edged and just a bit of discolouration. I did notice that a couple of areas on the arms are also more “wrinkly” / mush, but not much. I also read about a fungus/virus.
Do you think that’s what’s going on?
I very much hope you can help me out!! Thanks so much in advance!!
Unfortunately it doesn’t look good. I was surprised in your email when you said you hadn’t watered it since August. And then after the move that you kept it hidden behind boxes (where it presumably didn’t get light.) The move is going to be tough on any plants, but no water and no light is not something that a plant can survive.
In general if you get another one to try again I would recommend watering every 3 weeks. They should be in a very bright room or get a couple of hours of direct sun.
I recently became the caretaker of these plants. They have not had much sunlight and I am acclimating them back into full sun over the next few weeks. I am keeping them under a mesh tarp to let them get diffuse sun and I plan to put them into larger pots with some fertilizer (3-3-3). Is there anything that you can help me with based by just looking at the picture or do you see any thing I should change with my plan? I am guessing they are mostly some form of Euphorbia erythraea forma variegata but am not really sure.
Thank you for your time, Rich
Aside from the Opuntia which is the only cactus, the white ones are Euphorbia “Ammak” and the green ones are either the green version of “Ammak” or are probably Euphorbia trigona.
Depending on where you live they may need to be indoor. They are only hardy down around 32F, so we recommend them indoor in the SF Bay Area in the Winter.
Fast draining cactus soils for all of them. The cactus needs some good sun. The Euphorbias can handle light shade to full sun.
Do not fertilize a lot or these will grow into giant trees too quickly. Very little water – every 3 to 4 weeks should be fine, although more if it is sunny and hot.
My cactus is sick. A few weeks ago it was fine and beautiful, maybe a few tiny (pin prick or freckle sized) raspberry red dots on it, then – BAM – I looked at it yesterday and could barely believe it was the same plant. I don’t know what to do to treat this plant and protect my other plants.
It has strange rings (brown filled with raspberry/pink edges) and brown spreading patches. I’ve already looked online a little and couldn’t find anything like it.
Is it terminal and I should start chopping off branches to try to grow a new plant before the disease spreads to the entire plant? Do I isolate and treat all the plants in the one pot or is this a Euphorbia-only fungus? Isolate all the plants within a ten foot radius?
Also, will I get a response via email or will I have to check the blog? Both?
It looks like a virus from the ring pattern. I don’t know what caused it but it could have been from a sunburn – if the plant was put out into direct sun after having been inside or protected, or if it got turned around. If the infection is on one side of the plant only then that indicates it was caused by a sunburn.
You can try to treat it – I can recommend Oxidate by Biosafe, which is a ready to use disease control, or Neem Oil, both of which we carry. But the prognosis is only 50/50. If the plant survives it will have scarring.
Go ahead and isolate the plant in the meantime.
You can also check out the blog now – the answer is there too. Share with friends!
I’ve attached a few photos of my cactus that I’ve had for 10-12 years. My friend gave it to me as a joke because I kill everything, including ivy, thinking that maybe I could keep it alive by just leaving it alone. So for those 10-12 years it sat in the same window and never moved until 2 months ago when I switched jobs and it came with me. It’s been getting brown spots like I tried to show in the picture. This office may be a little colder than the last one but no more than 5 degrees-the sunlight may also not be as direct -instead of sitting on the sill it’s on a cabinet behind it and a little to the side. Also, I’ve never repotted it because I don’t know what to get or how to do it.
I’ve tried researching online but I haven’t been able to identify the type. So, my 2 questions are: Do you know the type/name? and is it dying? If so, (my 3rd question I know) what can I do to save it?
I appreciate any and all advice! Thank you, Laura
Laura, Your plant is a Euphorbia, possibly Euphorbia hermentiana. While not in the Cactus Family, it is very hardy like a cactus as you have experienced for the last decade or so.
It’s a little hard to tell from the photos, but there is some rot, and maybe a lot spreading through the plant, but maybe not. If the problems are isolated it should be able to come through.
The first problem is that it has never been repotted. Euphorbias are remarkable in being able to stay underpotted for so long! But not for ever. Add in the move, and many plants will experience shock from a move, and that can be enough to cause these problems.
These Euphorbias can handle bright indirect light, so the new location should be fine. But you will need to reduce the amount of watering for the lower light levels.
I recommend spraying the rot portions with a good quality organic fungicide; we sell Monterey Neem Oil.
The big problem is going to be repotting, which can cause more shock. You may want to try to stabilize the plant before repotting. Then you can follow along here: How Do You Repot a Euphorbia?
Euphorbia ammak, this may also be called the “Green Form” but then the real species E. ammak is a green species and the standard variegated E. ammak is more properly called E. ammak “Variegata” or better yet Euphorbia candelabrum erythreae variegata.
That’s kind of crazy that we would call one plant by another plant’s name. Why would we do that?
This one will get as tall as your ceiling, and no taller. That’s because you will have to prune it down when it gets that tall, and not later.
Let that be a lesson to you all to not get Euphorbia sap in your eye. Don’t get it on your hands and if you do wash your hands thoroughly and immediately. Don’t wait ’til later because you will have forgotten long enough to touch your eye and then look at what happens.
Hello, my cactus is getting a light brown discoloration on his arms, I am very worried, please advice on what to do to save my cactus. I stupidly placed the cactus inside a barrel that didnt have proper drainage and when I noticed one of his arms truning light brown i figured it was because of the water, I drilled some holes into the barrel and drained a little water until it was dry. the cactus arms started turning light brown and it seems to be spreading. I am attaching 3 pictures, the first one was taken one week ago, the second one was taken today. Is there any way the cactus can recover from this? What should I do?
Thank you for your time, ed
The branches can be saved, but since the rot has started from the bottom the whole base of the plant, roots and all, can’t be saved.
First be aware that this is a Euphorbia ammak which has a caustic milky-white latex sap. You need to wear gloves and long sleeves and eye protection when working around this plant. Given its height, this is going to take at least 3 people to safely take cuttings. One to hold the plant, one to hold the branch being cut and a third to do the cutting. If it is taller than it appears you may need a 4th person to help hold the branch as it is being cut. Please make sure you feel safe with all this before you start. I recommend using a serrated bread knife to cut, and blankets to wrap the branch before cutting.
Basically you need to cut each branch off above the rot, making sure there is no rot inside at the cut edge. Spray the cut with hydrogen peroxide and set aside to dry for 2 to 3 weeks.
If you see rot when you cut, keep cutting higher until there is no rot in the branch.
When the branches are fully healed over you can plant them in dry cactus soil and keep dry for a few more weeks. Water only every 3-4 weeks. Do not re-use any of the old soil as it is possibly infected.
Danger Garden visited the Cactus Ranch in New Mexico and photos ensued. I especially like the ghost Euphorbias. But there’s enough photos to last anyone in their right mind hours of fun and entertainment.
I’m having an awful time with mildew (or some similar fuzzy gray fungus) on Euphorbias in my house, one room in particular. I tried neem oil, but that just makes everything defoliate. Then I tried spraying with basic copper sulfate (it was the cheapest and least toxic thing I could find at the garden center), but that has no effect. So I’m looking for something not found in nature, ideally something that’s illegal in multiple countries. Bonus points if it’s a yellow-green liquid that produces its own dry ice fog. Can you recommend anything?
 Affected so far: Euphorbia milii, Euphorbia drupifera, Pedilanthus tithymaloides, Synadenium grantii, Euphorbia bougheyi variegata, Euphorbia trigona, Euphorbia lactea, Pedilanthus ‘Jurassic Park 2.’
We have the same ongoing problem with Euphorbia milii, various Pedilanthus and Synadeniums and a few others. It is an ongoing battle with organic fungicides. We do use a product called “Mildew Cure” from JH Biotech, although it is also as natural as neem, but it works better on Euphorbias in our experience. Hydrogen peroxide might work. I don’t know of any systemic fungicides to recommend, but if you want something not listed for this use try a sulfur smudge stick used for seasoning wine barrels, and you light them.
I have a question on what to do about my Euphorbia trigona – it had been ill about 2 years ago and was treated with Neem and then brought into the house and recovered nicely. It kept growing taller and taller and never branched. It finally threw two branches this summer and grew another foot taller…it is now 40 inches tall! It is still completely upright with a chop stick secured to the bottom 6 inches, planted in a 6” deep terra cotta and happy. Should I just let it continue to get taller and taller? OR should I cut it down to size and let the potted bottom half alone – will it sprout branches? Then I would re-pot the top half?
Is it a must to use a rooting solution? I did not use any kind of rooting solution when I put the top of the cleistocactus that rotted off (of course, I did remove all rot and then let the bottom dry for awhile) into some cactus soil. It seems happy and has started growing a new fluff of top furry hair J. Will it root without rooting solution?
Thanks for your time, once again, to help me figure all this out.
Karen, It’s just about too late in the year to take Euphorbia cuttings, so if you do want to cut it and re-root, I recommend waiting until next year and taking the cuts between May and August. We do ours on July 1. The Euphorbia cuts are easy to get to root without hormones so long as they are well callused over.
The pot its in is too small, so it would be happier in a larger pot. Probably a 10-12″ pot.
And finally, these Euphorbias can be grown much slower with much less water. It’s amazing how long you can go between waterings. I recommend about once per month to really slow down its growth, although if its in a sunny hot window it may need a little water every 2-3 weeks.
With regular water, these will top 8ft. pretty quickly. We’re often asked to come into people’s homes to cut them down before they hit the ceiling. Peter
The easiest way to tell them apart is to cut them open. Or look at the spines. Either way you figure it out, keep protected when pruning.
“I spent Valentines Day crying and in pain from burning eyes so bad I had to call the paramedics. That day I pulled lantana that had interweaved into pencil cactus. I was so careful not to get any cactus sap into my eyes. It was awful pain. The paramedics said just to keep your open eyes under running water. It took about four hours. Now I am afraid of my garden.”
My heart goes out to Kurt, an innocent gardener who tangled with Euphorbia tirucalli, which is not a cactus but an African Euphorbia called pencil tree….
Like all Euphorbias, this one contains caustic white latex sap that would burn the lips of any animal that tried to eat the moist, succulent flesh….
Nick the skin of any Euphorbia and you find big white drops of latex come pouring out. Nick a cactus and the sap is clear or green. Sap color is key to telling a Euphorbia succulent from American cactus….
One experience of mine proved that flecks of latex that landed on the forehead or in your hair can later travel in your sweat to contaminate eyes, nose and mouth. Wipe it away and it’s on your hands too. Another gardener contaminated his eyes in the evening by taking off the shirt that he wore when working with Euphorbia that day.
It doesn’t take long to learn the lessons of the Euphorbia. By the way, E. tirucalli is a beautiful houseplant as well as looking benign while being one of the more caustic of the Euphorbias so it doesn’t mix well with children.
Here’s a photo for your fear and enjoyment.
And here’s one in habitat.
Big! Why, that looks like a tree. Everything grows bigger in Africa. But keep it inside in the Bay Area since it’s not hardy at all. It will turn to slime with one cold night.
would it be ok if i sent you a photo of something about which i have a question? i have a euphorbia with multi branches and within the past week little yellowish dots have appeared where one might expect spikes to be. hard to describe, thusly if i could send you the picture it might be more helpful.
karen vero beach florida
And here’s the picture:
And the good news is…
It looks like Euphorbia trigona and the dots are unopened blooms!
I got a “Euphorbia lactea” (not sure if it is correct) few months ago, but it took me long time to understand how I should take care of it, and now it is in trouble.
I have attached few pictures and I suspect it may have a stem rot fungus and some sunburn scars?
Yes, I know I really did not do a good job… it is my first experience with outdoor plants and I may have forgotten that I now live in Abu Dhabi and the weather here is really hot, until last month the average was around 42 degrees Celsius, reaching 48 during the day, this month it started to get better and rarely goes above 42.
Anyways, I used to overhead watering to clean the branches from the sand storm, common in this region, twice a week, or whenever the soil seemed very dry. It looked fine for a while, but as you said chicken comes home to roost. Two weeks ago one stem started to look bleached on the top and slowly it started to shrink and the discoloration moved downwards. I got worried and started to search the information on the web, now paying more attention to it I noticed that the same maybe happening on other stems.
What should I do?
Meantime, I moved the pot to an area where it does not get the full sun during the all day, stop watering like a crazy and put my Adenium away to avoid any contamination.
Thank you so much.
Glaucia Abu Dhabi
Glaucia, I’m not really sure how to advise you on taking care of the Euphorbia in a climate where the cooler month is 42 degrees C (108F). We would water rarely, but you will have to water more regularly – only just letting the soil dry out between waterings. I would take it out of the sun completely, and only let it get indirect light, possibly indoor.
Overall the plant is looking OK, with just some of the branches having been damaged. It does look like they burned in the sun and heat.
I recommend removing the damaged branches. Since this is a Euphorbia, with poisonous milky white sap, wear protective clothing, gloves and eye protection, and wash thoroughly if you get any on you. Since the branches are not very big around, you can cut them with a pruner, or slice through them with a serrated bread knife. Make sure you cut below the damaged parts. Keep the exposed ends out of the sun until after they’ve healed over.
We have a large – 4-5 ft. – Euphorbia growing in a pot in our living room. Have had it about two years with no problems. Recently I noticed one of its arms is getting a black die-back at the very top. The die-back is dry to the touch and the plant flesh is slightly soft but dry. A few photos are attached. Any thoughts on what this might be and cures for it?
Possibly, I’m not watering enough. I give it about a gallon of water every 3 months or so. It gets about 5 hours of direct sunlight in Half Moon Bay
I welcome your advice and thanks!
Allen, It appears to be just one tip, the other branches look fine in the photo. I don’t know what has caused this particular problem. You might want to think if there’s anything different about that one branch – is it the only one getting direct sun? No sun? Is it touching a surface?
It’s possible it has caught an infection, but if the rot has stopped at just the tip it might be just cosmetic damage at this point. You can cut the branch off below the rot, at a slight angle away from the light source, making sure there is no evidence of rot in the branch below the cut. Whenever cutting Euphorbias wear protective clothing – long sleeves, gloves, eye protection – since the milky white sap is caustic. Spray with Hydrogen Peroxide to help the cut heal faster.
In general I would recommend watering every 3-4 weeks. These Euphorbias can handle being WAY underwatered, but only for so long before they start to show damage. Two years isn’t that long yet, but I would water more often. If you haven’t repotted it in 2 years you might also want to try that, into fast-draining cactus soil. Good luck Peter
Mark writes in with a quick photoshop of his front yard wanting a plant for a hole in front of his window.
Hello Folks at Cactus Jungle.
I recently pulled a huge bush/tree thing I hated out of my front yard and have been in search of a good replacement. (I’m actually in a hurry to find something new because it left my entire living room exposed to the street traffic — poor planning, I know.) One plant I was considering for a replacement is an acacia, specifically an acacia baileyana ‘purpurea’ and was wondering if you had any thoughts. If you had positive feedback on that choice, is there any possibility you have them in stock? (I realize it’s not a succulent…)
The reason I pulled what was there before (an Angel’s Trumpet), was because it was really messy — dropping leaves all over my cactus and succulents below. And I wanted something more colorful that would also complement the colors of the house. (Below is an embarrassingly unprofessional Photoshop’d exploration of what it might look like.) But I am certainly open to other suggestions, if you had any.
Pluses would be drought tolerance, not too many dropped leaves or berries, grows quickly but not too large (I do plan to prune though), enough foliage to create a visual barrier, but still let some light into the front of my house. Sculptural is always nice too. Originally I was jones-ing for a beautiful, giant euphorbia. But I know it would cost a bazillion dollars and might not serve as a good screen from the traffic.
As I’m writing this I worry it might be sound like I’m asking for free design advice. But I trust you’d say so if it felt that way to you.
Thanks for any input.
P.S. Speaking of huge euphorbia (I saw your recent blog entry about it), I have to remember to send you photos of ones I saw in Southern Africa recently. Enormous giants! (Wait, that’s redundant, isn’t it.) Massive. And all over the place. And in bloom.
Now we do have the Purple Acacia in stock, so maybe he’ll get that and all will be good, but if you have any other suggestions for Mark, let us know right away!
Dear Cactus Blog, This is one of our large Euphorbias although 3 of them are showing similar damage. My thought was that this might be rodent or other animal damage, but I’m not sure. I have spent some time observing both day and night and haven’t seen evidence of anything attacking. Do you have any suggestions?
Thank You Very Much for your help, Bill
Bill, It sure looks like something is chewing on your Euphorbia, however since they are nasty and poisonous, god only knows what. I suppose deer or rats if they were really really hungry. We sell a product called Deer Off, but then we also recommend Euphorbias as deer-resistent. Peter
I desperately need help with my Euphorbia Flanaganii Cristata! I got this plant bare root a few weeks ago, and potted it in a gritty mix like I did with my other succulents. But this one has gotten worse since. The yellow is spreading and the base looks brown (see attached picture)! What can I do to save it?
Thank you for your help.
It looks like your plant has either caught a fugal or viral infection and if it has continued to spread it may just be too infected to save. However if there are still green, uninfected looking parts of the plant you can try cutting them off, dipping the cut area in hydrogen peroxide to disinfect and help seal the wound. Please not that all Euphorbia have nasty milky sap and you do not want to get it in your eyes or on your lips, wear gloves and eye protection when cutting and handling! Let air dry and after a week or so of drying and healing, repot the cuts in fresh soil and a clean pot. You can use rooting hormones if you have it or liquid kelp to help speed up the rooting process or just let it root on its own, though it may take more time. Keep warm and the soil on the dry side the first month.
By the way, here’s a picture of a healthier one growing in Iowa. You have to scroll down for the photos.