Cactus Blog 

Hello,
I found your blog online and it had been very helpful to me. I am really grateful that you answer questions from people that are not your customers, as well! I recently got a pot with three small cactuses in it and am having trouble identifying them. I have attached a few photos. For reference, the center cactus is about 2″ tall. What do you think? I am particularly curious about the one on the right as I can’t find anything similar searching online. I would like to know about their care requirements and if they are suitable to continue growing in the same container.

Thank you,
Regina

PS – I am aware that the l little red flowers on the center cactus are fake. I’ll remove them eventually…

Regina,

The left is a Mammillaria and the right is a Euphorbia (probably E. meloformis) while the one in the center, after the paper flowers are removed, is maybe a Myrtillocactus although it can be hard to be sure when they are young.

They can grow together in that container for a couple years and then they will outgrow it and need to be separated. Care depends on where you live, but the 2 cacti need a lot of direct sun – at least half day, while the Euphorbia is less. Not a lot of water, but the watering depends on whether the pot has a hole. Either way, make sure the soil is dry between watering, probably every 2-3 weeks.

Peter

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?

 
Kind regards

Mel

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.

Good luck!
Peter

I have had euphoria lacteafor almost 9months. It has glued rocks to support and has no hole in bottom of pot. Should I transplant it to another withhold and if so, how to do it? No change or growth in 9 months.

Thank you for information you can provide!

Norma
Pensacola, Florida

Norma,

If it is a crested lactea then you won’t see much growth anyway – they’re very slow! But yes, please do repot – no drainage and glued rocks can be a disaster for plants – please rescue your plant ASAP!

If you are not sure how to repot it, maybe there is a local nursery you can visit who has cactus soil, and tips for repotting into a larger pot with drainage?

Peter

Hello

I’m hoping you could give me some advice, I live in the UK and bought an Echinocactus grusonii a few months ago. The guy told me to water once a fortnight and add Baby Bio plant foot or tomato feed in each alternate. The first few times I watered it it was fine but this time I think I’ve killed it. Within a day of feeding the spines have started to die around the base, it’s got dead looking patches and darker green patches that look like water marks. It doesn’t feel squishy but the bottom looks like it’s shrinking in on itself.

Have I broken it? Can it be saved?

Thanks in advance
Victoria

Hi,

It’s hard to tell for sure from the photo, but it is not looking great. I think there may be 2 different pests, but again it’s hard to tell from the photos. The base looks like it has started to rot, in which case it is too late to save it. But if it is firm, maybe I am misreading it. If it is firm, you can try to use a systemic fungicide, and spray the rest with an organic pesticide. Not sure what’s available in the UK, but we use Bonide Infuse and Monterey Take Down Garden Spray.

In general we would suggest watering every 4 weeks (every 2 fortnights?) for the cooler parts of the year, and every 2-3 weeks when it is hot and sunny. Do not fertilize regularly with any tomato fertilizer – it’s too strong for cacti. Use an organic low strength granular all-purpose (like Down to Earth All Purpose) and use it at lower strength than recommended. Use only twice in a year – spring and mid-summer. Let the plant grow slow and it will be healthier.

Peter