You know that we get questions here at the Cactus Blog, and we post them on the blog, and we like when readers send us photos. However, sometimes we’re stupid and lose the photos. But I’m posting the question and answer anyway. Because that’s just the way I feel today.
I saw this cactus in a magazine and thought it was really cool. Any idea what kind it is or if cactus jungle sells it?
p.s. Got the Neem Oil you suggested!
Alas the photo is too small to tell for sure, but it is either an Echinocerus, Echinopsis or an Euphorbia. But we have all three that look very similar.
What a great resource! Attached is a golden barrell of mine. I cant exactly describe what it is doing, but as you will see it is striping or shriveling? Maybe varigation (sp)? See attached. I dont think these are wrinkles, although it is very difficult to get a finger in there and tell. The cactus has been around for many years and has been healthy and otherwise appears so. It is currently in a greenhouse, with filtered sunlight. Any thoughts or anything to worry about?
Matt (portland oregon)
Plants grown inside usually have a few quirks. Your Barrel (Echinocactus grusonii) looks pretty good, the odd lines are likely seasonal growth lines, so I would recommend giving it a bit more calcium, as the spines are getting thinner and try upping the light exposure, Echinocactus can take full sun once they are over a few years old.
Q: I have a cactus tha is over 15 years old. I was watering it the other day and was picking it up when it almost broke in half. What should I do to keep it alive.
Can you email me a photo? If it is a big break it may be that you need to cut it off and re-root it, if it is a species that will re-root. If it isn’t you will need to “splint” it and hope that it will heal up strong enough to support it’s weight. But a photo would help me give you better advice.
…and, yes, here comes a new email with photo… so now we get the rest of it….
I would recommend repotting in fresh cactus soil, mulching with a small rough gravel like lava or small crushed rock and laying the whole cacus on it’s side on top of the gravel, it should root along the length and then grow new “pups” along the length and turn in to a many headed cactus. Do not use smooth gravel like aquarium gravel as it stays too wet. It does look like it would like more light… so try moving it closer to the window or to a south or west facing window.
I have a question for you about a beautiful Ferocactus latispinus that I purchased from you in February. The plant had been living at your shop, on one of the outdoor racks, for many months through the Berkeley winter. About a week after I bought it I moved to Los Angeles…en route to New Zealand. Unfortunately, the cactus had to stay behind in southern California, where it is living with my mom. About 5 days after we (the cactus and I) arrived in LA I noticed that parts of the plants were experiencing what looked like bleaching or loss of pigment. It was warm in LA, but not too hot, and for acclimation reasons I had put the plant in an area where it would get some direct but mostly filtered light. I thought the bleaching would be a temporary effect of the transition to a warmer and/or brighter setting, and that the pigment would return, but my mom just sent me some photos and it looks like those parts of the plant are still quite pale…about the color of the pale/yellow form of Euphorbia ammak v. variegata. This concerns me, but the cactus does appear to be (somewhat) “happy” as it is growing and the region of new growth on the top of the plant is the deep green color I’d expect. Can you explain what I’m seeing? This little guy is my favorite plant and I want to do whatever I can to keep him healthy and happy. I’d send a picture but my mom doesn’t have a digital camera. If you need a pic for proper diagnosis I can arrange for one to be taken. Thanks very much for your help! Hope all is going well at the jungle.
Department of Zoology
University of Otago
It sounds like the bleached parts are a sign of sunburn, it most likely happened by the north facing side suddenly getting rotated to face south after the move and the skin cells that were not ready for UV getting a good zap. It will take a long time to heal up and if it was a bad burn it may convert the burned areas to “bark” rather than green skin… but the chlorophyll may still recover. As long as the growing tip at the crown looks green and healthy, the plant will eventually grow out it though it may have scars.
p.s. does your post-doc in zoology get you out to see the Tuatara? They are so cool! I want to meet one someday.
The red succulent I just wondered what it’s called. It grows great in the clay soil.
The biggest cluster of “little blue/green beans” is on the left side of my shadow in the vertical center of the shot. There are a few more above those and more in the center. And there’s a lone one below the big cluster. They have a spike-like texture to them & they’re the size of peas. I love them & would like to try them in the other, better soil.
The more colorful one is a selection of Sedum rubrotinctum, possibly the clone called ‘Aurora’, although it is hard to tell from the photo… colors of the named clones will vary on light and soil conditions. The Blue-green one looks more like a Grapto-sedum hybrid, but I am not sure. I would need to see it in person or have a closeup photo.
Q: I was given a sunrise cactus three years ago, and it was in full bloom. It was beautiful! However, it hasn’t bloomed since then. I have it on my dining room table, and it gets morning sun. The plant itself is very green and healthy looking, but no buds. I have put it outdoors in the summer and will do so again this weekend. Any suggestions on how I can get it to bloom again?
A: Your plant sounds very healthy! Now your sunrise cactus, so named because the flowers open in the morning and close at night, isn’t a desert cactus but rather one of the family of epiphytic jungle cactus, sometimes called holiday cactuses. This particular variety is often called an Easter cactus, because of the spring blooming period. And yes, it’s related to your Christmas cactus. Some sun year-round is desirable, but be very careful of direct, hot sun at any time of the year. They do love to be outside in the summer!
In the fall, like poinsettias, they require a period of cooler, drier, longer days to bloom well. In October, reduce watering, keep the plant in a dark place from late afternoon to dawn and replace in strong light each morning. The cactus is going through a period of semi-dormancy then, so do not feed during this period. You should have beautiful blooms in the spring!
Well, that made for easy blogging this afternoon, farming out my chores to those crazy Bay-Staters. That should give me time to write some more limericks…
Q: Hi Hap,
Thanks for your help with the cactus! The tubular shaped cactus has bad discoloration and little white larvae/mites? in the saucer. The beaver tail/flat shaped cactus thankfully does not have the white bugs in the saucer but it has some rough patches of brown discoloration.
Any suggestions on how to correct this problem?
They need a good spray/drench with a Neem Oil solution. It looks like they actually have two types of bugs, scale and mealy bugs as well as a start of a fungal infection, most likely brought on by the bugs sucking on their sap. Neem Oil will kill the bugs as well as help the plants fight off the fungal infection. We use a 1% Neem dilution with great success. We have it available at the nursery.
The Las Vegas Review Journal takes all kinds of questions from their readers, including this simple one about some sedum.
Q: I have a Vera Jameson sedum that has grown and spread. However, the plant leaves in the center are dying. I have planted this in the front yard where it receives full sun all day. I water it every day for four minutes in the morning with a shrubbler. I have placed rubber mulch around the base of the plant and two days ago I added some liquid plant fertilizer that I diluted in water.
I also have a Spanish bayonet yucca that the bottom leaves are turning brown from the tips. The trunk looks healthy. This also is receiving full sun and I have been watering it for four minutes each day on a shrubbler drip system.
A:…When I first read your e-mail, it struck me that the problem was either with the soil or with irrigation. But, after finding out that you are watering every day for four minutes, I think the major problem for you is water.
Four minutes of water does not tell me much. I do not know if four minutes of water is the same as 1 gallon or 1 teaspoon. You should apply enough water so that you irrigate to a depth of 12 inches for the sedum and even deeper for the yucca. The sedum will require water more often than the yucca….
When you do water, try to water more deeply and less often to give the soil and plant roots a chance to breathe.
Both plants… should not be watered daily. The yucca can be watered less often than the sedum, but probably not more than once a week. I would think every two weeks should be adequate, but it is hard to know without knowing other things like what the soil is like.
Well, I could have told you that. Of course, there’s more to the answer than all that, so click through to find out about build up of salts and the author’s opinion of the rubber mulch too.
Q: I have a graptoveria ‘debbie’ that is giving me some difficulty. it had a bloom spray on it when i purchased it 2 months ago. the spray is still on it and no blooms have opened. it sits in an eastern window and although it is getting leggy (not enough sun) it is getting burn spots on it (too much sun). what do I do with it? cut the spray and move to different soil (currently standard cactus mixed with specialized pumice from garden center)?
Please help. If it is lighting, please tell me how to add extra lighting for them. Thank you thank you thank you.
Your plant is fine. It’s hard for me to be sure since the photo is a little out of focus, but it looks like there are 2 blooms that have opened on the bottom of the bloom spray. It is possible when moving a plant to a new environment that a bloom can abort, but it doesn’t look like that has happened here. Hopefully the rest of them will open. You might want to get it closer to a sunny window.
As for the plant, it is a tiny bit leggy, I suppose, but not too bad. Basically it looks fine. The “burn” spots you mention are just the plant losing bottom leaves. All succulents lose bottom leaves. Check out my instructional video.
Q: I bought the arrangement in the attached photo and the leaves are beginning to yellow and fall off. I’ve been watering every 10 days or so. Ususally I soak it for a few seconds and then let it drain. Any help?
It looks like you just have a dead branch, the rest of the plant looks fine. Trim off the dead part and it should be fine. You can also bring it by for us to take a look at…
Sometimes we have to interpret the questions we get. In this case, it wasn’t too hard to figure out what she was asking about.
Q: My husband and I were in Arizona and saw a lovely flowering (multi colored) cactus. We think the name was “troia” or “troya”. We live in southwest Florida and wondered if it could survive here and, if so, where could we buy it. We couldn’t find any information when we googled “troia”.
Sometimes our answers are simple and direct, other times, well, a little wordier…
The name you are looking for is “cholla”.
There are many different species of plants that are called cholla, all in the Opuntia family (actually the Opuntioideae subfamily), with the genus being either Opuntia, Cylindropuntia, or Austrocylindropuntia.
(Basically, the Opuntia family has been divided into prickly pears (Opuntia) and chollas (Cylindropuntia). And then just for fun the botanists added an “Austro” in front for plants that are native to South America. We don’t actually agree with these divisions, and so our website lists them all still as Opuntia.)
Some common Arizona species include the Teddy Bear/Jumping Cholla (Cylindropuntia bigelovii) and the Buckhorn Cholla (Cylindropuntia acanthocarpa). We also like the Pencil Cholla (Cylindropuntia ramosissima).
As for how well they will do in Florida, well… Not well. It really depends on your humidity, which is generally too high throughout SW Florida. The chollas are a pretty dry plant. Some of the other Opuntias, the prickly pears, will do better in Florida. You can even find a list of those that are native to Florida.
Q: Hi there,
Just wondering if you could give me some pruning advice…. Euphorbia candelabra on her terrace… overlooking the River Thames… too big for the space….
Is it possible to prune it back? One of the cactus experts at the Hampton Court Flower Show here told me it would die if I did so… it will have irritating sap…
Any info you could give would be much appreciated. I don’t come across many outdoor cactus here in London, usually just red geranium and buxus balls and so could do with a bit of your much more expert guidance.
Look forward to hearing back from you
Then we get the compact answer:
Yes, you can prune the Euphorbia, if it is done right it will not kill the plant, but it will cause them to scar and then branch over the next few years. You should prune now during warm weather so it has a chance to heal before your wet and cold winter. It should be easy to cut with a pruning saw or a serrated knife. The sap on Euphorbia candelabra is very toxic so make sure you wear safety glasses or use a full face shield, chemical resistant gloves and long sleeves. You do not want the sap in your eyes, as it can cause blindness! To stop the “bleeding” use 3% Hydrogen-peroxide from a druggist, put in to a spray bottle and spray the cut heavily as soon as you are done cutting. It will make the sap stop flowing fairly fast, but watch for splatter while you spray (a real good reason to wear a face shield).
Good luck (and we would love an emailed photo of a before and after to put up on Cactus Blog).
…about the question people ask us, “Why is my cactus/succulent (turning yellow) (losing leaves) (turning brown) (dying)?”
But then I decided that I didn’t want to answer that question.
If I were to answer it, I’d have to ask questions back to the questioner. For instance, I might ask, “Do you know what the species is?” or “When was the last time you repotted it?” and of course, “How often do you water?” and finally, “Can you bring the plant in or send a digital photo?”
Often people try to describe the plant, “Oh it’s green and it’s got long thingys on it, but it’s not too spikey…” or “It’s got round leaves” so I’ll point to a plant and they’ll say, “No that’s not it, it’s taller than that” or “More round”.
That’s enough whining for today. Go back to enjoying your Saturday afternoon. Go on…. You don’t have to go outside, but you can’t stay here…
Q: I’m trying to find a succulent that my paternal grandmother had. It’s been referred to in the family as hens and chicks, mother of thousands, string of pearls, and tears something-or-other. She lived in Bakersfield, CA.
It has long leaves, and produces ‘babies’ on the edges, which fall off at the gentlest touch, and root easily.
Can you help?
A: What you are looking for is what we call the Mother of Millions, or I suppose, if you have less ambition, Mother of Thousands. Definitely not Hen and Chicks or String of Pearls which are completely different.
It’s not good to have Pachypodium problems, I always say.
Hi Hap! What’s going on with my Lamerai’s?
It looks like you have at least two insect problems: Scale, the brown and tan bumps here and there on the leaves, as well as spider-mites. The leaf burn and curl is a combination of not liking the brand of Neem Oil you used on the tender new leaves and the bugs draining too much sap. The good news is it should grow out of it, but if the first application of Neem did not kill all the bugs (watch for little crawlers) I would suggest using a lower dilution of your Neem oil and respraying in a week, so it does not burn the new crop of leaves. If that does not work we can discuss more drastic measures….
I was wondering if I could get an opinion from one of the experts about a disease(s) my cactus seems to have acquired. I spoke with someone on the phone the other day, and he suggested I e-mail some photos. Here’s the gist:
I purchased a beautiful 4′ cactus at Cactus Jungle about 10 mo ago. About 1 mo ago I noticed it had developed what appeared to be a nasty case of scale. I applied a potassium-based organic miticide to the surface 3 or 4 times over the course of a month, and the scale seemed to mostly disappear, but at about the same time, I noticed two additional types of lesions on the cactus:
1.) Raised, blister-like lesions, filled with a black tarry liquid, began to break out up and down the shaft of the cactus (see photo #1 below). The began to multiply and coalesce into lesions several inches in length. Some appear to be drying up and turning gray now, but others are still popping up.
2.) Flat, dry brown speckled patches that don’t scrape off, some reaching up to several square inches, have formed near the bottom of the cactus, but appear stable (see photos below).
I was wondering if you might know what either of these two types of lesions are. Do you think they relate to the original scale problem, or might they be related to the treatment I used, or perhaps just stress? What would you suggest as treatment?
Any advice or help would be greatly appreciated
It looks, from the photos, like the plant has a chemical burn. It is also possible, if you scrubbed the dead scale off that the plant’s skin was damaged. Either way, it appears to be cosmetic damage, for the most part, and the plant will probably come out of it fine, with some scarring. If there are still any soft spots on the plant, then gently clean these areas with household peroxide.
I love Cactus Jungle (!) and it looks like I’ll be needing to make a trip soon to replace my indoor Euphorbia Ingens. The plant was gifted to me by a friend many years ago when it outgrew his little apartment. It was about 5′ tall at that time and it is now at least 6-1/2′ tall with several branches. It used to produce a multitude of little green leaves and grew a few new “arms” and then about five months ago I swapped it’s location with my Euphorbia hermentiana, so the hermentiana could have the best light for a while (although all the light is pretty good). I was about to swap them around again when I noticed the Euphorbia Ingens was dying. It started getting soft and rubbery at the tips of each branch including the top of the main trunk. Now about 2″ of each branch is very soft and yellow and I’ve noticed a brown creeping area on the largest branch. This is happening pretty fast. I think one of my [bleeping] cats decided to use the trunk as a scratch post as I’ve noticed some old healed pinprick patterns on the base side facing the wall. I don’t know what caused the dying — lack of proper sunlight, cat damage, virus, other. Should I try cutting the plant in half (the bottom half below the branches does not appear to be sick) or simply have a funeral for the entire plant? My camera is on the blink so unfortunately I can’t send a picture!
By the way, the Euphorbia hermentiana is growing insanely large even with pruning new branches and I’ll bring a picture to the store to see if you guys think I should have it repotted. I can’t repot it myself without risking life-threatening injury…and I don’t want to damage this lovely plant.
If all the branch tips are showing signs of soft rot, it sounds like a virus. You could try cutting off all the infected parts, cleaning the cuts with Hydrogen-peroxide and hope it will stop the infection… but if it is a virus it is likely throughout the plant. Please be careful and remember the sap is toxic and you do not want it on your skin or worse in your eyes! Wear chemical resistant gloves and eye protection if you start cutting.
Please bring by photos and we will be happy to give better advice.
We have many different kinds of cactus where we live, some growing wild and some either given to us or we purchased. My wife was very excited yesterday when she went our to water our many plants and trees. She noticed one of the cactus plants had a beautiful flower. We have had the cactus for approximately eight years and have never seen it flower. My wife asked me to take a picture of the flower and use it as my desktop background on my PC. I have searched the internet trying to identify the type of cactus it is and get some information on the specific plant and had no luck. I have attached the photo to this email. Could you please identify the cactus and tell me where I can obtain information about the plant? I am glad I took the picture yesterday because when I checked it this morning the flower had really drooped and is not pretty at all. We live in Chaparral, NM, just outside of El Paso, TX.
Thank you. Roy
Your plant is a very nice Echinopsis subdenudata, it use to be called Lobivia subdenudata but all the Lobivia got “Lumped” with Echinopsis…. It is native to Bolivia. We have a little more information on our website here.
Cactus Jungle: Greetings,
I am very worried about 12 bamboo plants (Psuedosasa japonica) I bought from you a little less than a year ago, which I have planted outdoors in large redwood planters in an alley behind my house in Noe Valley, SF. The alley is fairly narrow E-W running – the plants get direct sun during the mid-day hours because the hill I’m on slants towards the south. I water them once every week or two, and this spring have given them one dose of fish emulsion. While there are new shoots coming up at the base of the plants, a noticeable portion of the leaves are beginning to yellow or brown – worrisome during the fair springtime weather. Additionally, there is an apdhid infestation on the plants – they exude an oily residue covering the leaves. Do you have any experience with this problem?
I have invested both time and money into these plants and am not thrilled to see them fail in less than a year. Please see the attached jpegs: I would be most grateful if you have any advice or information which would help me care for the plants. As far as I can tell the species is appropriate for the climate, but let me know.
The yellowing leaves is from stress, from the aphids (sucking like
vampires on the leaves) and the fact we have had a very dry spring and
the plants are thirsty. Aphids are usually not a problem if the plant is
getting enough water and nutrients, all though they are often an issue
while recently planted plants are getting established. As your plants
mature they will become less prone to aphid problems.
You should spray the aphids off with a blast of water from the hose.
There are easily washed off and be a soft insect are usually fatally
injured by a good jet of water. You can also use insecticidal soap or
Neem Oil, but only use them after our “hot spell” that has just started,
is over. Hot weather and insecticides are a bad combination for your
plants! Spray in the evening, not during the day or morning as the soap
and or Neem Oil can cause leaf burn in the hot sun. I would recommend
using a hose end sprayer and really coating the leaves to kill off the
remaining aphids and eggs glued on to the leaves.
In a raised wood planter like yours, the bamboo is going to need a bit
more water than if it was in the ground (where its roots could pull in
moisture from all around). The wood breaths and so the soil inside dries
out faster. Water well, at least once a week, dry soil can be hard to
re-wet, so a slow soaking with a trickle of water is usually best, a
soaker hose ran down the length of your planter, twining between the
plants is an easy way to water your bamboo. Give it more water if it is
warm and windy, as this dries the bamboo out faster through
transpiration in the leaves. After a year in the ground you should be
able to water less, since the plants will have better established root
systems to pull in available water, but remember that raised beds always
take more irrigation.
They should “Out Grow” the aphids and stress pretty quickly as long as
our projected drought holds off long enough for them to get established.
Psuedosasa japonica is a great drought tolerant bamboo but like all
young things needs a bit of care to grow up strong enough to face the
big, bad world… I think your will take off with a bit more water and
knocking down the aphid infestation.
I bought a Cactus for my wife about two years ago from a local home depot. For the life of me I dont know what kind it is and I dont know how to take care of it. Attached is a picture of the plant. My wife and I would be very happy if you could help us out and tell us what this thing is and how to take care of it.
Your cactus is most likely an Opuntia subulata monstrosa.
It looks like it needs more light, so try moving it closer to a west or
south facing window. It also looks like your potting soil is too rich,
with way too much organic material in it. Re-pot in a quality cactus
soil that does not have any “forest” product in it. If you can’t find
that locally mix two-thirds pumice or Perlite with one-third standard
potting soil. Do not add sand (it stays too wet). Water about every two
weeks during the summer, once a month in the winter. With better light
and soil your cactus should take off and grow into a cool lumpy mound
that looks like a “star-trek-ian Xmas tree” in a few years. O. subulata
is a very fast growing species and the monstrose mutation of it is too.
Q: Hi there,
I have a Pachypodium lamerei (I am pretty sure based on the pics from your site) from you guys that I have had for about one or two years. It fell over!!! It looks like the base of it was too skinny for it’s thicker top. What can I do? I love it, the leaves look healthy and it never looked sad to me, so it was a surprise when it just fell over. I don’t over water it, if anything I under water it. Any suggestions?
I really appreciate it,
Could you email us a photo of the plant and a close up of the base where it fell over? If not please bring it by the nursery so we can take a look it. Pachypodiums will sometimes loose their roots to an infection over the winter, if that is the case, it will need treatment and help regrowing roots. It could also just need to be re-potted in a larger pot with fresh soil.
Resolution: They brought the plant in, and it wasn’t too skinny, and the roots hadn’t rotted. The base had rotted from an infection, and the plant was dead. We were sorry we couldn’t help save it. It appeared they had really underwatered it. We recommend watering every 2 weeks.
Today’s question comes from concerned parents. Well, not so concerned that they didn’t ask the question before the son had taken care of the problem.
Q: My son recently dug out a cactus while landscaping. The lady told him the neighbors called it “the cactus from hell”. When he was done he had tiny needles, the size of a hair, all over his body and around his head and neck, even though he never touched the cactus, except with a shovel. It took him hours to get all of the needles out, and had to throw away his shoes, they were covered in them. This happened in Indiana. What kind of cactus is it? Thank you.
Jim and Joy
A: Jim and/or Joy,
Opuntia microdasys is most likely. The spines will go aerosol when you
whack it with a shovel. It is also known as the Cow-Blinder cactus, and
we spray it with soapy water before we handle it.
We Get Questions always prefers to have pictures to go a long with the questions, and here we have a nice portrait of a cactus.
I have had a cactus for approximately fourteen years. I was living in Chicago when I bought him and currently reside in Fremont (northern) CA. I love “Borus” and have only recently discovered that he is a Cereus Montrose. I have always kept him in a clay pot until 1 1/2 years ago when I transplanted him to a plastic pot because of his size. He is now 4″1″ tall from the base of the pot. He is currently in a pot which is 22 1/2″ diameter and 21″ tall. Unfortunately I keep him outside. In the winter I have put him in the garage during rain and at night when the weather is cold.
I would like to know if I should transplant him. His pot is cracked and his top roots are as wide as the pot on one side and 1/2″ from the side on the other. I do not know how deep his roots are since I can”t lift the pot. I have been looking for a clay pot but can’t find one any larger than the one he is in.
I did find a ceramic pot which is somewhat bowl shaped, 22″ in diameter on top, but 26″ three inches down. I know he should be transplanted into a pot two inches larger, but would five inches hurt? I found the internet to be too expensive for pots and could not find the right size.
Attached, are some photos of him. He has never flowered. I didn’t know he would flower. I thought I was caring for him properly. but now know I was wrong. I did recently water him with Cactus Juice fertilizer a few weeks ago and have noticed the top branches which were getting soft, have hardened up a bit. His yellow tinted color has also faded a bit.
Please look at the attached pictures and advise me on what to do to make him a healthier and happier cactus. He has been with me for so long, I would be heartbroken if anything should happen to him. I don’t know if your answer will be on the internet or you will send me an email? I’m new at this. Thank you in advance.
Your Cereus monstrose would be happy with a much larger pot, though clay would be best, plastic just holds too much water in the winter. A five inch jump is not too much for a plant that size. You could also plant
him in the ground in Fremont (where he would soon become a tree) as long as you amended the soil so he had good drainage. Cereus like yours are hardy enough to be happy planted outside in the Bay Area. My own Cereus monstrose in planted in a raised planter in my Berkeley backyard and handled 25 degrees without damage.
Yours looks like he could use a bit of fertilizer and minerals and that should green up the yellowing. We use slow release organic nutrients with great results, cactus are slow growers so they like slow food as well. If you use a chemical fertilizer only use it a low strength and not very often. Make sure to use a fast draining soil without a lot of organic material.
Well, it may be a little too late for that, what with the pictures.
Hi, I called a few weeks ago about my cactus, attached are photos. I just moved from Richmond to Martinez and my cactus started turning a beautiful deep red color on one side but now it has a disturbing orange stripe down the center. Is it ok? Thank you in advance for your help.
Your Euphorbia looks like it has both sunburn/sun-stress and a fungal infection. The red is sun and the orange/brown/black is a sign of a fungus infection. I suggest spraying it with Neem Oil at 1 or 2%
solution. This will hopefully stop the infection. Spray to the point of run off, in the evening, not morning or afternoon as the oil can add to the sunburn. Respray after a week.
Tiffany asks, are there any cacti that don’t have those dangerous sharp spines? I have small children and like the idea of growing cactus, but naturally, I am concerned about their sharp spines and subsequent injuries.
Yes, there are cacti that don’t have sharp spines.
Well, that was easy. On to the next question, I always say.
Well, it’s not really a tale. More of a newspaper story. Really, even, it’s the Arizona Republic answering your questions. Let’s go to the tape:
I have a saguaro that has holes being made by a cactus wren. I know that is what cactus wrens do, but is there any way I can stop it or at least repair the holes after they leave?
This question is brought to me in one form or another about once a year, and it always sort of irks me a bit.
First of all, the wrens didn’t make the hole in the cactus. That was the work of a woodpecker or flicker. The wrens just move in after the original owners leave.
Cactus wrens actually prefer cholla cactus.
Second, unless the cactus is diseased or otherwise really stressed, the holes aren’t going to hurt the cactus. The plant heals itself from the inside by sealing off the hole with a polymer called lignin.
Third, you should be happy to have the cactus wrens around. And all the other birds, lizards, small rodents and everything else that might be attracted to your saguaro. Do you have any idea how many people would like to have something like that in their yards?
Just relax and enjoy your cactus.
That is a fantastic answer, so I hope Clay Thompson doesn’t mind that I quoted it in its entirety.