Haageocereus is quite a poorly studied genus it seems, but some of them have a prostrate growing style, while others are more columnar. Nonetheless, Tony's plant sure seems to be a Haageocereus.

I remember posting a pic of an epi where the slow-release granules were visible & I was told not to use them, as the cactus soil shouldn't stay wet enough to dissolve. Huh, I keep my Epi's (assuming you mean Epiphyllum, not Epithelantha) really wet all the time so that instantly strikes me as b...

No, that's Stetsonia coryne (toothpick cactus), not a saguaro.

What is interesting with very large tuberous roots that eventually fill the pot is where all the potting soil they displace goes to? Some species seem to actively digest the soil mix and break down bulk mineral aggregates, while others just don't seem as capable of doing so. Of course some of the s...

Without knowing what the C&S soil is, I can't comment too much, but I'm going to guess it's very rich and dense, like most bagged soils. Personally I'd go: 20% C&S soil 50% turface 30% gravel (although if the gravel has very round, uniform, small grains then I probably wouldn't use any and m...

I don't think there's any advantage to rooting them in soil, since they will just sprout roots even if they're left out in the open. Either rooting on soil or in the open work fine.

Well at least you have a handful of new plants now, if you want them.

Very exciting species, great new additions.

Haha megarhiza by name and nature. Perhaps I should repot my seedlings from their tiny communal seedling pot.

Have you watered them? Have they received any water? They should grow like weeds given plenty of water. Opuntia fragilis is quite fine with being kept moist all the time.

The windows are different between Frithia and Fenestraria. Yours is Fenestraria rhopalophylla. F. rhopalophylla ssp. aurantiaca has a yellow flower, so you'll need to see it's flower to nail down the ID.

Thanks for the info, Dan. This year I sowed some Frailea angelensis from MG. I had terrible germination, and all of the seedlings died of mould. I'm making an order for succseed now, and including 6 species of frailea. Fingers crossed. 8) Frailea seeds are quite short-lived, and don't usually last ...

Looks like Ferocactus glaucescens to me. I'd say that pot is too tall and the bottom two inches might never be utilised in that plant's lifetime.

Bulb bowls or other dishes can be useful, as can bonsai trainer pots (which are way cheaper than the proper ones). You can stake the plant while it develops a good root system too.

I grow my Geo's in the same mix as all my other cacti and they're doing great - 20% 'organics' and the rest 'mineral' with some additives. Overall an acidic mix with no limestone or gypsum. I don't like to waste my time making fanciful soil mixes. :wink: They're not as difficult as they're passed of...