Questions31 Aug 2010 12:57 pm

Dear Cactusblogger,

I live in South America, Surinam and work in a tropcal plants nursery
(family owned). I’ve been making a catalog of our plant for years now
(what can i say, grandpa’s been negligant), as we have well over a
million plants. I’m constanty running into a dilemma about an agave we
have. Whenever i try to categorize it i basically flip out!Is it an
americana, is it not an americana. Some sites say it’s an americana
others say it’s not. So, my thought was, perhaps you could help me. I’m
sending you a picture!Please help!Do you know the real botanical name?

Many thanks in advance,

Our answer after the break… (more…)

Questions20 Aug 2010 09:41 am

I’ve just stumbled across your blog, and being a cactus lover immediately spent the day reading it. In order to help you continue the great work, I have two questions for you:

1. What’s the best size pot for my Golden Column cactus? I’ve had it for about 5 years and find it awesome for intimidating neighbors.

2. Could you help me identify this cactus? I’ve had it for a few years and have always found it interesting, but never tried to figure out the name.

Also, if you guys have any advice on sprouting Draco Dracena seeds (or cacti seeds) it would be much appreciated.


Your Cliestocactus looks like it is fine in the pot it is in for another year or two and then you will likely need to repot to something at least two inches in diameter larger.

Cactus #2, Looks like it is a Mammillaria heyderi or one of the many subspecies of M. heyderi, however there are several other Mammillaria species that have a very similar look… like M. mystax. It could also be a hybrid, since there are a lot of them in cultivation. Do you know what color the blooms are?

Dracaena draco seeds have very hard shells, so they will need to be carefully scarified, (chipped, filed or rubbed between course sand paper until there are scratches in the shell) to help to get enough water through the seed casing to cause germination. Do not cover the seed with soil, but you can lightly coat with sand to help keep them moist, they need bright light for most of the day to germinate. We use high-output fluorescent lights on for 18 hours. Keep the soil moist, but not soaking wet, clear germination domes help, but watch for mold and excess algae growth. Keep warm, 75-85 degrees. Germination usually takes about 2 months but it can take longer, so don’t give up.

Cacti seeds have different requirements depending on types and where they grow in the wild. But the general rule is similar to the draco directions for large seed types and with small seed skipping the scarification process and just scattering on the soil surface and then lightly covering with sand or crushed horticultural charcoal. Keep moist, but not wet and under bright light. Some sprout with in a few days and others take months or longer. Plan on leaving the seedlings in the sprouting trays at least a year, since it can take them that long to get “fat english pea or small grape” sized which is when we usually reline them out to grow on.

Good luck,

Questions&Reader Photos19 Aug 2010 02:55 pm

Hi! I have an enormous cactus that is eating my house. I need to remove it but didn’t want to just throw it away, it’s quite impressive but unfortunately it’s ruining the foundation. Do you know anyone that would want this cactus? I attached a picture.

Thank you! Krista

Yowza, that’s a big Cereus!

I don’t know anyone in Southern Cal off hand, but I’ll post it on the blog for you. Also, we find Craigslist works well.


If anyone is interested, email me and I’ll forward it along to Krista in the 310. Just a warning, though, if you do go to cut it down, make sure you don’t let the giant branches fall on the roof, or yourself either. Just sayin’.

Questions19 Aug 2010 11:52 am

We’re the women who were in on Sunday and were arranging, and finally purchasing the manzanitas, sage and the little euphorbia obessa. We could use your help.

While we were there we talked with Keith about what we think is a fungus that killed the tree that used to be in our front yard. The fungus appeared on the stump after we had the tree cut down (it was dead.) We’re concerned about planting the new trees close to this area, that they might also be attacked by this fungus.

Anyway, Keith said that we could send a photo of the fungus and he would try to identify it.

We’re going to have someone install these plants for us and would appreciate your quick reply.

Thanks for your help.
Lynn & Joanne


It looks like your stump is being eaten by a bracket fungi called Trametes versicolor, or “Wild Turkey Tail”. The brackets are the fruiting bodies of the organism that is actually inside the stump eating the cellulose. This species only attacks dead or nearly dead hardwoods so it is unlikely to be what killed the tree, but took advantage of the food source after it was dead.

So we do not believe this fungus would cause any problem planting a new healthy manzanita.

But it is a amazing and beautiful artifact.

Questions12 Aug 2010 12:13 pm

The shortest email question, evah!

is this san pedro?


(This email and photo was sent to us by Hamza. Your answer was provided by Peter.)

Questions07 Aug 2010 09:19 am

Hi, I had questions several years ago about my Cereus Monstrose and you helped me then, so I hope you can help me now. My Cereus is quite large, over five feet. It has developed black spots on it which I am afraid are parasites of some kind. The first of these spots occurred last year and someone at the Jungle recommended putting Neem oil on them. This is not working. I cut a black spot out and the area turned black What should I do? I am very attached to this plant and I do not want to lose it. Do you make house calls?


It looks like the cactus has an infection, which is causing the rot spots. Probably viral which is difficult to treat. You treat with cleaning out the infected spots and sterilizing with hydrogen peroxide, and feeding the whole plant with kelp and neem.

We do housecalls, and if you would like we can come out and treat the plant for you. Please understand there is no guarantee we can stop the infection.

Questions05 Aug 2010 10:17 am


Here are the three different types of plants my wife and I own. We are tryin to take care of them as besdt as possible, but were not sure exactly what to do. I know that one of them is an alo plant but i dont kno if its dying cause its starting to brown, and the one cactus is a mamillaria type cactus. do you have any tips or helpful instructions on how to take care of them?? we are trying to get help on identifying the flower shaped cactus.


First, the pink succulent is an Echeveria “Metallica”. Second, It’s hard to tell from the photo if there is anything wrong with the Aloe.

For general advice, the Mammillaria wants a minimum of 4 hours of direct afternoon sun and should be watered about every 3 weeks – a little more when it is hot in the summer, and less in winter.

The Aloe would like about 2 to 4 hours of morning sun, and the Echeveria wants almost as much sun as the cactus. For the 2 succulents, you should water every 2 weeks, and again a little more when it’s hot in the summer and less in winter.

All 3 plants should be in a fast draining cactus soil, and from the photos it looks like there is too much forest product in your soil, so you may want to repot them into a better draining cactus soil.

When watering go ahead and drench the soil and let it drain away, never letting them sit in water.

Questions20 Jul 2010 08:07 am

Hiya guys,
Every bit of advice you’ve given me has been so spot on,
now I’m having a problem that is making me so mad.
They are farmed by my many many ant colonies in the yard,
and every time any of my succulents produces a flower,
BAM! Black aphids cover it, and I just clip it off,
because it’s so nasty. Even my giant Kniphofia flower stalks are not immune.

What would be a good plan of attack so I can enjoy my succulent flowers
for awhile before the black aphid plague descends down upon them?

Thanks so much.
PS. Your advice on Sluggo was great.
I have to reapply often, but the snails got the message.
Stay away from my succulents!

With Aphids on succulents you have a couple of choices:

Hose them off the blooms with a soft spray of water, being soft bodied insects they are easy to dislodge and then you can really blast them when they hit the ground. Think Aphid soup! I usually hold the bloom stalk with one hand and spray with the other. It is sort of messy, but usually works.

Use insecticidal soap, and then after they are dead you still have to wash them off, since they die in place, still piercing the plant with their vampire bites, their zombie bodies are still annoying. But the soap usually leaves eggs unharmed so you may need to retreat before the blooms are done.

Use a more aggressive insecticide like Pyrethrin which will kill them and most of the eggs, but is absorbable by you… so use with care and caution!

Of course as you know they are farmed like dairy cows by the ants, so you also need to work at knocking down the ant population which with the Argentine Ant Super Colony that is eating California will be difficult, try adding some ant treatments around the succulents as well.

Take care,

Questions05 Jul 2010 11:30 am

Hi Peter,
Can you please identify this Aloe for me?

Thank you!

You have what looks to me like Aloe mudenensis. They are growing really nicely there. Sweet!

Questions01 Jul 2010 11:41 am

Hello Peter,

I hope you and Hap are both doing well and business good. I need some help with an offspring of our large Opuntia which has a white spoor like growth on it. The plant doesn’t seem to be hurt by it at all, but none the less I wanted to know what it is and what to do about it. Let me know if you have any knowledge or advice. As we need some small items I hope we can get up your way soon.

Take care


The Opuntia has a bad infestation of Scale Insects. They are sort of Limpet-like vampires of the pest world. You should be able to get rid of them, but it will take a bit of work. First, spray the branch down with straight rubbing alcohol (or Vodka) and then loosen them with an old paint brush, the alcohol will dissolve the shellack they coat themselves with when they glue down as adults. After doing what you can with the alcohol and paint brush, rinse with a “stern” jet of water from the hose, this will help blast off more them. Follow up with a good spray of Neem Oil at 1-2% solution, you can get this at any good nursery, as it is used on Roses as a natural insecticide and fungicide. Respray with Neem after a week at least three times to break the life-cycle of any hold outs or eggs that survive. Make sure to spray the Neem in the evening and not during the hot sun, as the oil needs time to disperse as to not cause burning of the plant. You should also fertilize that plant and give it an extra drink to boost it’s natural immunities.

Take care,


Questions28 Jun 2010 11:09 am

I am a subcriber to your newsletter and was refferred to you by a friend. She told me that if I email you a photo of a plant, that you would be able to identify it. Can you please help me identify this cactus and Please tell me what I need to do to make it green and healthy as it has been showing clorosis (yellowing) for sometime now. I rescued it off the street corner as someone was throwing it away. I have repotted it with cactus soil mix about 4 months ago.

Any info, would be greatly appreciated.

Thank you.

You have a Cereus peruvianus and as you say, it’s clear that you have “rescued” it. We use slow release organic nutrients (we sell our own mix, too), so if you haven’t fertilized yet, now would be a good time. (If you’ve used something stronger, that can possibly be a cause of the yellowing.) When our cactus look yellow after the winter, we also will add Kelp Meal.

Questions16 Jun 2010 06:55 am

I have several echeveria and graptoveria which I bought from you and have just finished planting in my new garden. They look so much alike that I’m wondering what is the difference(s) between them, especially differences in what the mature plants will look like. (I was hoping for flat to the ground hen and chicks appearance, but perhaps I won’t be getting that?)

Thank you.
Carol (Vallejo)

It depends which species you have, but generally the echeverias are the hen and chick style, stemless and on the ground, while the graptoveria do sometimes get a trailing stem. If you send me photos, I can confirm what your individual species will do.

Questions15 Jun 2010 08:56 am

Hi Kevin,

When you have a chance, can you tell me what these are? I got them from different places.

The first one was given to us, has beautiful bloom;

Second one hitch-hiked with another plant I bought, with a big round root under all that tentacles and had a ring of tiny yellow flowers a while ago;

3rd one I got from Target, reminds me of someone wiith a bad hair day;

4th one spread like waves/snakes.

I cannot find these from any books I have, so thought you might be able to help. Is it OK to trouble you? or is there another source I can ask about plants?



Here are the attached photos:









You have:
149. Crassula falcata, also known as the propellor plant.

536. is a crested Euphorbia, possibly Euphorbia flanaganii

537. is definitely Euphorbia flanaganii, also known as Medusa’s Head – would certainly qualify as bad hair…

538. Tephrocactus articulatus v. papyracanthus, or the Paper-Spine Cactus.

Questions07 Jun 2010 07:23 am

HI, I was wondering if you could tell me what kind of plant this is, and if it is unusual for it’s size. It was growing for some time then this tree like appendage came shooting out of it. It is well over the top of our 1 story home. Easily close to 2 stories high. Picture is included. Thanks for your response.

Vista, CA


Your plant is an Agave that it is starting to bloom. It looks like it is an Agave americana or “Century Plant”. The blooms will open soon and look amazing, the stalk will eventually (over the next year or two…) dry out and be a sculptural corpse… Agave bloom stalks were often used as alien trees in old science fiction films. Agaves grow for a long time (but not really for a century) and then bloom and die. However there should be “Pups” or baby plants around the base of the blooming mother plant that will repeat the cycle, as Agave have a habit of cloning themselves before trying to do “sexual reproduction”. If there is another Agave bloom in you area and you have Agave moths, you might even get seed pods. If not the flower stalk will sometimes try another cloning strategy and grow plantlets where the blooms are, that eventually helicopter down and root in where they land.

Take care,


Questions05 Jun 2010 07:30 am


My son is very worried about his cactus. He has had it for about two years and it started to turn black (please see attached photos) two weeks ago. We live in Wisconsin, and his cactus receives about 8 hours of sunlight a day. Any advice would greatly appreciated.

Thank you,


The cactus is mutant Gymnocalycium that is grafted on top of a Hylocereus stem (the green part). It is a chimera pair so that the bottom graft can feed the top bright-colorful part that lacks chlorophyll since it was likely exposed to gamma radiation to kill the chlorophyll and bring out the wild otherworldly color. The sad reality is the mutated part is generally short-lived because it has compromised immunities and can’t build all the proteins it needs.

The black infection showing in the photos is likely a fungal infection (it could also be a virus). If it is a fungus it may respond to being treated with a fungicide. We use Neem Oil, which is usually effective, while having low (to none) toxicity issues around mammals (us, kids, pets…). Neem Oil is used in toothpaste and cosmetics. You should be able to find a ready-to-use Neem Oil product at your local nursery. Follow the directions and spray it down well. Retreat after a week. Hopefully it will stop the infection, but the top graft will always be scarred. If the infection continues the top graft may fail and turn all black; if it does cut it off and treat the green base with Neem. The Hylocereus base is actually a cool jungle cactus that can be treated more like an orchid and if it starts growing new arms it can eventually bloom and even fruit, which are those cool and tasty looking “Dragon Fruit” you might have seen at the grocery store.

Good luck,

Questions&Reader Photos29 May 2010 07:33 am

You never know what kind of common names you’re going to get from a cactus.

(Here’s) a picture of a cactus I have that blooms once every May.  Four tall white flowers that look like umbrellas. I would like to know what kind of cactus it is. Thanks.


That’s an Echinopsis alright, formerly known as a Lobivia. As for the particular species, it’s hard to tell from the photo, but it might be Echinopsis subdenudata from Bolivia.

Questions27 May 2010 08:48 am

Hi, we had a cactus planted in our front yard about six months ago. It’s getting browned and hard at the bottom, but not mushy (which I thought would indicate overwatering). The browning is working its way up the plant, but if it IS overwatering, of course I don’t want to continue to contribute to that problem by watering it more thinking it’s too dry.

Any suggestions!? Thanks!

Matt B
San Diego

It’s a little hard to tell exactly what I’m looking at there. It’s probably just barking, i.e. the plant is turning into a tree and creating a trunk at the bottom with bark. On the other hand, it could be an infection. The key question is: Is the area soft or firm? Firm is good, soft is rot and that would be bad.

If it is soft, then given the location of the rot, you probably need to cut the plant down and get rid of the root mass. You can then save the branches, let them dry in shade for a week or two, and then plant them in a fast draining cactus soil.

A warning: This is a Euphorbia and it has caustic sap. Wear protective clothing, long gloves and eye protection. Don’t get any of the milky white sap on you.

What rot in a Euphorbia looks like.

Peter, I really appreciate your response.

It’s hard – very hard – and inching upward even though I’m not watering the plant at all, so it sounds as though it’s barking.

Again – thanks so much!!
Matt B

Questions26 May 2010 08:46 am

Hiya guys,
I just got back from my tour of the US,
and my buddy gave me some cow’s tongue opuntia when I was passing thru New Mexico.
I was wondering if the fruit is edible and the same as standard prickly pear.
I never see this in the Bay area, is it rare out here?

All opuntia fruit is edible, just some taste better than others, some are less spiny and easier to get at than others, and some are already bottled in fancy sweet vinegars made in Italy.

Questions24 May 2010 06:40 am


I’m heading to a wedding and would like to bring a hand-made succulent arrangement as a wedding gift.   What are some succulents that can survive the lack of sun that Eugene has most of the year?  Are there good resources that show which succulents would work well in that climate zone?


P.S.  I’m thinking it can be an indoor arrangement to help regulate the ridiculous amount of rain it would get otherwise outside in Eugene.

The best options for low-light succulents are the Haworthias. They tend to be small, but there is a lot of variation in the look. Also, there are a number of Crassulas, green Aeoniums, and even some Aloes that can handle fairly low light levels, though not full shade. For outdoor in Eugene, there’s a book called “Hardy Succulents” that list lots of succulents and the colder zones they can handle.

Blogs&Questions&Reader Photos21 May 2010 03:04 pm

Hello… I’m a regular reader, and very occasional commenter on your blog… you may remember me from a prickly pear cactus jelly post you linked to… [Ed: Yes we do remember!] regardless…

I bought this plant in July of 2008. When I bought it, it was labeled Mammillaria species… and that’s it. Nothing else…

I’ve included 4 pics… 2 of the plant when I first bought it, which I posted on the blog in hopes that some kind, kind person out there knew or could blindly guess the species. They couldn’t…

there’s also one with blooms from last year, and a current pic showing fruit…

If you could help me ID the thing, I’d really really be grateful… thanks for your trouble…

Claude from Random Rants and Prickly Plants

I typed up a response and saved it in drafts, and now its missing, so I don’t know if you’ve already received an answer from me, but you have a lovely Mammillaria perbella. The fruit in one of the photos is edible, though tiny, and only if you haven’t used chemical insecticides. If grown outdoors, it would be way more spiny, but yours is looking great.

Also, see here on Claude’s blog another picture of the Mammillaria in question. And don’t miss out on the beer can garden post. Really, you don’t want to miss it.

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