Powdery Mildew on Euphorbiaceae

I’m having an awful time with mildew (or some similar fuzzy gray fungus) on Euphorbias in my house, one room in particular.[1] 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?

Pedilanthus tithymaloides w/fungus

Euphorbia drupifera w/fungus


[1] 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.

Scale on a Prickly Pear Cactus

Good evening. Two days ago I noticed these spots on my Santa Rita Prickly Pear. Are these spots insects? Any suggestions on what to do? I bought this plant at Cactus Jungle and it’s one of our favorites.

Thank you,


Those spots are insects – Scale insects – the big spots are the adults and the tiny spots are the babies. Prickly Pear Cactus are prone to these and it’s fairly common in the Bay Area. We recommend starting off by dipping a soft-bristled paintbrush into rubbing alcohol and gently brushing as many of them away as you can. The alcohol will break through their shells.

As this is a fairly extensive infestation, you should use a strong insecticide – we recommend natural pyrethrins (not the synthetic varieties) and we do sell a couple brands that are safe for use on cacti – that you can spray on directly. You will need to get into the cracks and crevices around the plant, and even spray the top of the soil. Re-spray after 2 weeks and that should take care of it.


Succulent Cuttings

Hi there,

My boyfriend bought a really nice plant for me from your store and apparently he mentioned that I have some succulent questions and someone there said I should just email you. So here goes!

I bought these succulent clippings for a wedding in June. After the wedding I put them on a tray with paper towel underneath and just soaked the paper towel occasionally. They seemed to be doing fine but haven’t really grown any serious roots.

I tried to put them in dirt (as you can see) but the don’t seem to be doing as well now (maybe because the dirt absorbs the water before the succulent can get to it?).

Anyway, can you advise me on how to turn a succulent clipping into a free-standing plant? Thank you!

Best, Megan


It sounds like you are doing fine with them. It can take a few months, especially in winter, for those succulents to develop good roots. The plants should be fine in the meantime. Water every 2 weeks or less during the winter, more in the summer.

In general the best way to root cuttings is to let the cut end dry and heal over, then put them straight into dry cactus soil (we sell our own cutom blend). Don’t water for a week, and then start watering regularly same as if they had roots.

The plants do look like they might not be getting enough sun. I can’t tell if that was from before the cuttings were taken, or if it’s because they’re on the floor below where the sun gets to. But I would make sure they’re getting 3-4 hours of direct sun every day.

Good luck!


Mystery Bug


Mystery bug on pot with blooming Rebutia fiebrigii. Do you have any idea what it could be?

Your mad skillz & such

Hi there —

Any chance you can tell me what it is I’m taking care of here (in the foreground)? I bought it at a yard sale in July because it gave me Dr. Seuss flashbacks. Think maybe I haven’t been watering it enough, as it sure looks fluffier & happier since the rain.

And don’t judge my cacti/succulent bench mess! I’m trying to figure out where everyone needs to be for this our first winter together. I sure wish the kids not from CJ were already repotted in your soil, but, ya know, if dreams were thunder & all.

Thanks a ton,


You have a Senecio cylindricus (or possibly a Senecio mandraliscae). The plant looks happy and healthy, if a bit more Dr. Seuss-ey than is usual.


ID Question

Can you help ID this plant growing 50 miles north of Santa Cruz. Any ideas on a species?


Dustin –

It’s a Dudleya. 50 miles north of Santa Cruz is the Half Moon Bay area, so it is probably Dudleya farinosa, but possibly Dudleya cymosa.


Hardy Agaves

Hi, I’m a big fan of your blog and i was hoping that you might be able to identify this agave? I just picked it up at lowes and it was labeled as an aloe.  Fingers crossed that it’s hardy.

Paul from VA


You have an Agave, probably Agave potatorum. Also see here for lots more pictures.

They are hardy to about 25F (Zone 9b), so probably not hardy outside in VA.


Echinocactus Grusonii Questions

Good afternoon;

I have a couple of questions regarding my golden barrel cacti. I have five outdoor plants in a cactus garden on the northwest side of our home. I’ve noticed that the two smaller barrel cacti (one is about the size of a melon, the other the size of a grapefruit) have developed yellowish ribs and the space between each of the ribs is a light green. Are they not receiving enough sunlight? Should I place the barrels in pots and move them to an area with more direct sun? They get about 5 hours of direct sunlight this time of year.

I also water my barrel cacti about once every 10-14 days – are they receiving too much water? If it’s any help, I live in Newark, CA (about an hour south of Berkeley) and have bought some cacti from Cactus Jungle. I appreciate your feedback. Attached are two photos taken during the summer of the cacti in question.

Thank you,


From the pictures, the cacti look fine. In general, 5 hours is enough sun. A little yellowing could be a sign of too much water; reduce the watering to every 3 to 4 weeks except when you are getting over 90F. You can stop watering them now for the winter unless we have a particularly dry winter.


We Get Winter Cactus Questions

I stumbled across your blog and I have a few questions regarding my new copiapoa.
How often should I water it, and how much water should I use when I do? Now that it is winter I thought I would need to water it less. I just got it about a week or two ago and it was flowering–now the flower has closed up. Is this usually the case with this cactus?

I also have a succulent that I have had for about a year, I think I over watered it recently but I thought maybe taking a look you could tell if it is doing okay. I was wondering if I needed to plant it in a bigger pot?

Also, I live in Oklahoma, just so you could get an idea on weather.

Thank you in advance!


Cactus flowers only last 2-4 days, so it is not unusual that the cactus has finished blooming so quickly. It is unusual that it was blooming so late in the year. Normally you should see it flower in early summer. I would recommend some low strength fertilizer in spring and a little bit of extra bloom food.

For winter, put it in the sunniest window you have, water every 4-6 weeks, and pretty much leave it alone. In spring you can start watering about every 3 weeks.

When we water we prefer to drench the plant and let the water drain away – a kitchen sink is a good place for that.

The succulent is Crassula ovata, and it is fine. It definitely wants a bigger pot, but I would wait until spring.


We Get Cactus Questions

Hey Guys,

I have another one for your ID help … and it’s blooming for the first time (for me). Is it a Disco? Melo? Echino? species?



It’s a Melocactus, probably either Melocactus azureus or Melocactus violaceus.

Bamboo Transplant Questions

About a month ago, I purchased 4 Candy Stripe clumping bamboo plants along with pots and soil. Recently, they have started dropping leaves. I increased water to 2x a week from the originally advised 1x per week.

What else should I be doing?


Your bamboo plants are having a little bit of transplant shock – which is perfectly natural and nothing to worry about. Stop the extra watering – these are drought tolerant plants and need to dry out between waterings. Only water more than once per week if its very hot or very windy. You should see new tiny leaflets starting in the next few weeks.

If you used the Bioturf organic fertilizer we recommend, you don’t need to do anything more. Otherwise I do recommend some high nitrogen organic fertilizer.

Cactus in a Glass, UK Edition

Please can you you help with the following

I recently purchased a cactus (see picture Below) I was given to names either mammillarias – polythele and the succulent plant is a sedum or Crassula and Echinocactus

I was also told two different methods of feeding which are as follows:

1. As far as watering goes, you should give it a small amount, about half a mug every 10-14 days in summer and reducing down to a 1/4 mug every 20-28 days over winter.

from summer hill garden centre
2 Water once a fortnight March to October – suggest a cupful ( not a mug!!!)
October to March ignore it
Feed every month from March to October ( amount should be on whichever feed you get)
October to March do not feed

from Craig House Cacti

Please can you give me the correct name and how often I water it and feed it and
where I buy the feed

I am disabled and never looked after one.

Thank you, Mark

The cactus is a Mammillaria and the succulent is a Sedum. From the name of the nursery, I take it you are in Essex in England.

It’s going to be hard for me to give you exact instructions since I can’t tell what they are planted in. Terrariums are always a bit tricky, but it looks like maybe they are in small pots inside the glass surrounded by gravel. Assuming this is true, you want to make sure when you water that you only water right around the plant itself so that the water gets into the soil.

It won’t take a lot of water, maybe only a tablespoon per plant, but because it is so little water, you will need to water every week. You can water the cactus every 2 weeks in the winter, but the Sedum will want regular water year round. Make sure you don’t overwater – you don’t want any water sitting in the bottom of the glass.

As for feeding – Very little! since it’s in such a small terrarium. I would use a low strength liquid fertilizer like Liquid Seaweed (We use Grow More brand) and use only a tiny amount, no more than twice a year in spring and summer.
Good Luck,

Fast Growing Euphorbias

Hello Peter;

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.


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.

Aloe Questions After the Fact

Good day-

I purchased an Aloe plant from you about 3 months ago. Everything seemed to be going fine with it until about a month ago I noticed that at the base of each leaf, it appeared to be dying out. Over the past week its gotten worse and now the whole plant is rotted and needs to be throw out (see photos). Im wondering if you have any tips or ideas as to why this would have happened? It was in excellent temp and light all day long.

Any thoughts would be great, as Id like to get another one. Feel free to call me or email me.




It does appear that the plant rotted out from the stem. I don’t know what caused it to rot, but it may be over-water, or sitting in water so the soil doesn’t dry out. I don’t see any sign of pests, but something could have been chewing on the roots and that could cause this problem too.

If you see something like this happening again on another plant, send us a photo or bring it by the store before it’s too late, and we may have a better chance of diagnosing it and helping you save it.


Gene Wants to Know


I’ve been reading your blog for a while, and I really love when you tell which plant is blooming. Suddenly, I have a need for that too! Something popped a flower today, and I don’t know what it is. Can you tell? What are the other plants I have in that planter?



Nice grouping. And you’re in luck! I can name most of those for you. The blooming one is a  Titanopsis hugo-schlecteri. In front is Baby Toes, aka Fenestraria aurantiaca. Further forward and to the left, the dark one is Haworthia truncata. At the very front is Sedum spathulifolium “Cape Blanco”. And the last one, the light colored one on the right, is another Mesemb, but I’m not sure which species. Maybe a Cheiridopsis.


Does anyone here on the blog want to challenge any of my IDs? I’m open to suggestion.

Tony's Mesemb

Hello Cactus Jungle!
I recently moved my dinteranthus from a bright shade location to a full sun (bright shade for half the day) spot about two days ago. Today I noticed a strange lesion developing on one of the leaves (see photos). Overall the plant feels soft/a little mushy compared to before the move.

Any thoughts on how to approach this?

That’s definitely a sunburn. These are very delicate plants, so the prognosis is not great. The best I can suggest is to get it out of the direct sun, and spray with hydrogen peroxide to help it heal. If it survives the week, you can also spray it with some Neem Oil to help prevent any fungus.


Could you tell me what kind of cactus this is we are clueless and would love an answer.

Thank you for your time. Love your BLOG!

It’s a Cereus, possibly a Cereus hildmannianus or one of its sub-varieties. It could also be a seed grown Cereus peruviana that has grown elongated from low light and will shift from juvenile growth to adult eventually.

We Get Questions

Hello! Im having some difficulty with one of my euphorbias and my friend, Akos Kokai, suggested that I email you. My devil’s backbone has been growing this layer of powdery white dust for some time now. At first, it was very little and I thought it might be natural to the plant. But now it’s proliferating and killing off the leaves. Do you know what it might be? I’ve isolated the plant and have tried neem oil and alcohol treatments, but it keeps growing back.

Thank you!

It’s powdery mildew, a fungus. It’s pretty easy to cure, and we have some organic fungus treatments that work well, but these plants are definitely prone to it. We can recommend either of two products we carry: Safergro Mildew Cure or EcoSmart Garden Fungicide.

I recommend using one of these at the first sign of trouble. The Pedilanthus will do better with better air circulation and probably less water.

Mulching Your Cacti

Dear CJ,
I have a number of cactus and succulent varieties planted in the ground and they are doing much better than when they were in pots.

I am not too happy about the weeds among them.

After pulling all the weeds, should I cover the ground with medium sized redwood chips, clean rocks, or what? What I want is to have something easy enough to move aside to add more plants when needed and also something which will deter the weeds?

Thanks for your help.

We recommend gravel or lava, some kind of rock mulch that is rough, not smooth, and will dry out quickly. Also, we can recommend Corn Gluten, either liquid or pellet, after you’ve pulled the weeds as a pre-emergent herbicide.

Locally Available – Care to Try?

Dear Professional,

Hi, my Name is Nora. I have some really old cacti in the front yard of my house and would like to remove them or sell them. I am not educated about the plants, and during quick research of the plants I became lost in a pool of information on the diffferent types of plants, and removal process. I would like to to post them on craigslist to sell them, but I have no idea what to price them at. If they are not worth much I still would like give the plants to someone that appreciates the fact that they are 32 years old, and very large! They are pretty neat!


So I guess my question is, do you have any idea what these plants could be fairly priced at? Do you know anyone that may be interesed in these? Should I just have the gardener cut them down?

Clueless Cacti Owner

You have some very nice cacti!

The large single column is an Echinopsis terscheckii and could be worth a lot, from $500 to $1500 fully rooted in a pot at retail, depending on size and condition, but will be very difficult for someone to dig up and remove without damaging it. It should weigh more than 300 pounds.

The tall multi-branched is a San Pedro, Echinopsis pachanoi and this one would have to be taken in pieces – you wouldn’t be able to get it out of the ground in one plant. The cuttings are a couple dollars per foot, but beware that these are often sold to be ingested as a hallucinogen, so you may want to be careful about posting these on Craigslist.

The short multi-branched is an Oreocereus celsianus and if it can be dug up in one piece and rooted in a pot can be worth $300-$750 at retail, depending on size and condition. But it looks like that would be difficult for it, and it is not worth anything as cuttings.

I hope that is helpful to you.

Flowering Cactus Questions

We’re hoping you can tell us a bit more about this type of cactus, so that we can enjoy it in its full glory. I’ve searched online for care guidance, with no luck.

We purchased a beautiful Echinocereus grandiflora (lemon yellow) from the Cactus Jungle this past weekend. It had three fantastic yellow blooms when we brought it home. We placed it (in its pot) in our sunny yard and gave it a bit of water. After a few days, the blooms closed up and have a brownish appearance. Is this normal? We haven’t planted it just yet, but it is worth noting that we’re in a very sunny and windy location. Hope that’s okay for this beauty!

Thanks in advance for your help.

Cactus flowers tend to last only 2 to 4 days since they’re from the desert where they lose a lot of moisture very quickly. That’s also why they’re so big and beautiful – to attract the bees to pollinate them very quickly. So there’s nothing wrong with the flowers having finished. A sunny location is perfect for them, and they can handle lots of wind, too. As these grandifloras grow, they will have dozens or more flowers throughout the spring and summer. I recommend adding a bloom food in to the mix in February to get even more blooms after that.

Here’s one in bloom that’s been in the ground a few years (with different colored flowers).


Questions from the Yelp-o-sphere


I saw you have great reviews and excellent knowledge of cactus’ through Yelp and I’m hoping you can help me out. Attached you will find pictures of a cactus tree we have in our backyard. We are trying to figure out what type of cactus this is, can you help out? Thank you for your time in reading this, have a nice day.

Thank you,

American International Metals

The picture is small, but the plant is not a cactus at all but rather a Euphorbia, probably Euphorbia ammak, which is also known as an African Candelabra.



I have what I think is a 44″ 3-prong Euphorbia Ammak variegata.

I’d like to sell it on Craigslist. I’m curious if you would have an idea of how long it took to grow to this height? My (now) husband got it in 1999 I believe and has never repotted it. So my guess is that it’s been stunted.

Any info would be greatly appreciated!

Thanks so much,



Nice! It is indeed an Ammak. I would be concerned that it hasn’t been repotted in 12+ years, as that means it is underpotted, will be root-bound and could suffer from stress if moved. I don’t know how old it was before that; Ammaks can grow as much as 1ft. in a year, but 6″ per year is more normal. We would make sure the Ammak is freshly potted in a larger pot and in cactus soil (we would let it sit in its new pot for at least 3 months) before selling it.



Reader Question


I wanted to transplant this cactus but I am unsure if I should put the brown portion under the soil or if it is even worth replanting.  I meant to bring it in with me on Friday, but I forgot.  Please see attached photo.
Thank you for your help.


It looks like a case of “barking” (though I can’t blow it up to see detail… so it could be a pest but I don’t think so) but if it is barking the plant has been stressed and showing it’s age, the older green tissue has basically turned to a cork like bark to protect it from infection. To hide most of the bark you can repot it an inch deeper with a fast draining cactus soil and then add another inch of gravel mulch, we use 1/4 inch lava, but any crushed stone will work. Just stay away from smooth pebbles since they stay wet longer. The gravel will mask the bark without causing rot issues as long as you don’t over water. If you would like you can bring it by to confirm the barking and of course we do offer repotting services.

Take care,


Can You Help Me?

Hi I just called about the brown spotting. Thanks for your comments for possible remedy or better care.


It looks to me like it’s just age. The plant is probably fine, and forming bark in the lower “trunk”. Check to make sure it is firm, and not soft. If it is soft then it might be rot, but it doesn’t look like rot to me. Except one branch where there is more than one color – check there especially to see if it is soft or hard. If hard, then you are good to go!


Editor’s Note:

Today’s Rule of Thumb for this type of problem:

My advice to any of you if you have brown spots is to poke it. Poke it good. If it’s hard then it’s probably healed over, and if it’s soft then it’s probably a rot spot indicating some underlying problem. Now you know!

It's an ID Post! You Can Guess Along Too!

Hi Cactus Jungle:
Can you identify this plant? It is a cutting taken directly from a small tree-like woody trunk about 1-foot tall. It was up-right, no droop or dangle.

Leaves (?) very thin and stiff. Also please let me know if I can start plant from this piece.
Thanks much,

Do you have your guess ready for Rosa?

Check it out after the break… Read More…

Pests? You Don't Need No Stinkin' Pests

Hi Hap,

I spoke to you this morning about the below sick plant.

I’ve sprayed the Neem Oil mixture ( 2 caps Neem, 1 cap each of rubbing alcohol,dish soap & seaweed) and kept it out of the sun 2-3 times and this is what she looks like this morning. She is getting worse, not better & it hurst my heart to see her in this condition. Any suggestions??



Here’s a closeup, too:


That is quite the infestation! It does look like most of them are dead, but I see several types of aphids and a few mealie bugs as well that look like they may be alive. Since a good number of them seem to be dead and just still stuck on the plant, I recommend spraying the leaves with a firm (but not too aggressive) jet of water from a hose end spray head and knock them off. The jet of water will get rid of the corpses as well as squish a lot of the soft bodied aphids. Then let the plant dry and respray with Neem, making sure to coat the undersides as well as the tops of the leaves, make sure to coat the caudex and soil as well to get any still crawling around. Reapply the Neem in a week to get any that you missed or hatching eggs that survived. If they come back quickly after that you may need to use something more toxic than Neem. But let’s cross that bridge only if you need to, Neem is usually effective and relativity considered nontoxic to people and pets (it is used in toothpaste and cosmetics…) which is why we use it as our primary pesticide.

Take care,


Cabbage Head Agave

This question is all about the nature of cultivars. At least, that’s what I took the real question to be about.

I just bought an agave parrasana at your nursery today. I am just double checking to make sure it is the true agave parrasana, as sometimes confederate rose agaves are labeled as parrasana, and that is not what I was looking for.

Thank you,


I am not familiar with Agave “Confederate Rose” but as far as I understand it is a dwarf cultivar of A. parrasana. We do grow some other dwarf cultivars of A. parrasana as well. The nature of cultivars is that they are the species and not hybrids, however someone has found a smaller individual A. parrasana because individuals naturally vary and decided to grow it on and give it a cultivar name. This does not mean it isn’t true A. parrasana. As for what we carry, we’ve never grown any cultivars called “Confederate Rose”, so I assume the A. parrasana you got from us is the variety of A. parrasana you were looking for.


Reader's Cacti in Bloom

Hello there, Cactus Jungle gurus!
I was planning on sending some pics of my blooming plants in hopes you could identify them, but I think one is the same Cereus Monstrose you posted earlier today [Friday]. The first (is) of the blooms of what I think this the Cereus Monstrose, the (other) is the unknown. My plants are not very exotic, but they are quite special to me in their own way. We’re just south of Sonoma and they seem quite happy here, so long as they’re protected from the heaviest frost. I’m hoping I can finally put some name tags on them after you have a look. Thank you very much!



The first is definitely a Cereus monstrose in bloom. The 2nd was a bit trickier to find, but it is Harrisia tetracantha, although it used to be called Cereus tephracanthus since it appears to be similar to other Cereuses and is a night-bloomer, but the flower structure is completely different so they moved it to Harrisia for good fun.

Read More…

Cactus ID and Questions

Greetings Cactus Jungle,

I will soon be purchasing some of your Ultra Soil Blend for Cactus and
Succulent and was hoping you could tell me what kind of cactus is in
the photos below (I found it languishing outside an antique shop and
brought it home to provide it with a little better care). It’s
currently about 23″ high and sits in a 7″ square pot.


In addition, could you answer a couple of other questions regarding
the cactus:

1. Again, what kind of cactus is it?

2. Could you recommend the optimal size pot for its size?

3. How much direct sunlight would you recommend for it during the hot
days of summer here in Richmond, VA?

Many thanks for any advice you could offer. I appreciate it (and wish
your garden center were here in my neck of the woods).



Your cactus is a Cereus Monstrose, a genetic mutation off a more standard Cereus species. For pot size we recommend allowing enough space below the soil line for root mass that will match the amount of plant mass above. A 2ft. cactus would usually want to be in a standard 12″ pot, but it depends on height as well as width.

I can’t give you exact care for your location since I’m not familiar with your climate. But if you are hot you may want to provide it some afternoon shade.


July 2020

US Constitution


We Get Questions

Email your questions to:

blog [at] cactusjungle [dot] com