Ariocarpus and Aztekium sowing medium

[Cactisucc]

Hi guys, I've just gone and bought yet another big batch of seeds (my girlfriend will be over the moon ) and also receiving some from Aiko (HUGE THANKS!)

Anyway I have quite good success with my seed grown plants, however I've also decided to try some Ariocarpus Fissuratus and kotschoubeyanus v.macdowellii, plus Aztekium hintonii and ritterii... I've been reading so much about ideal mediums but just can't quite figure out what works best.

I know that Aztekiums grow in gypsum, but as far as I'm aware, and correct me if I'm wrong, gypsum (and limestone) don't do much more than inhibit growth which helps the plant in so far as it reduced competition from other species...

So I'd assume a mix with high proportions of non organic material should be sufficient?

If I list my soil 'ingredients' that I have at home, would some of you experienced growers give me your opinions on a suitable medium? If there's anything you'd consider essential but missing let me know too:

Scoria (red volcanic rock), pumice, 2-4mm aquarium gravel, silica (aka sharp?) sand, coir, redwood compost, worm casting, sphagnum moss and dolomite. (I also know where to buy gypsum powder but currently don't have any)

My guess would be to have about 85% mix of pumice and aquarium gravel, 15% coir, worm casting and redwood compost, or possibly just 100% non organic mix. But really I'm not sure with these species. For 'easy' species I usually use about 60% pumice, gravel and sand with some sifted store bought cactus soil with good success, but these stay in their sealed bags for 3/4 months, not 1-2 years.

Finally, what do you think of sterilising? I never do it and I haven't had any issues with mould or fungus since I started diluting the water with a bit of hydrogen peroxide, and I seem to have found the 'right' level of water, moist but not wet soil and decent humidity. Again, 1-2 years is a whole different story to 3 months.


Thanks so much in advance, happy gardening!

[Aiko]

I would recommend to use a mineral medium. I use a mix of 50% rough sand and 50% loam myself for basically all my sowings of a widespread genre of succulents.

Ariocarpus are not that picky. They just grow slow.

One thing to keep in mind is to grow species from Blossfeldia, Strombocactus and Aztekium via the baggy method. They are even slower growing than Ariocarpus, and need to be accommodated to prevent them from dying off due to lack of body mass in relation to heath. Sterilise the soil very well, and once you have sown the seeds in pots with warm moist soil, keep the bags locked for at least one full year, preferably two years. Pending if and how fast algae will grow in the pots eventually anyway, or when the moist has dissipated out of the locked bags as will happen eventually. You really need to cook the soil very well while it is wet, and still hope there will be no algae coming up. There is a risk it will happen anyway, so if you have much seeds it is best to spread the seeds over multiple pots and lock those up separately.

[DaveW]

See:-

http://www.living-rocks.com/cultivation.htm

[Robb]

I have used a mix consisting of 50% pumice 25% crushed scoria 15% sharp sand and 10% organic matter (mostly composted bark) for Aztekium and Ariocarpus with pretty good success. As Aiko said, Aztekium need to be kept in a sterile sealed environment until they are big enough to be able to withstand some drying out. If you can provide these conditions then they are easy enough to grow; just don't expect anything to happen quickly! Ariocarpus will grow whatever seed sowing method you use, but they will grow faster if you grow them under softer light.