BCSS - Forum

Hi,

I rejoined the forum after more than a decade: I had to stop the hobby due to the impossible combination of family, work and moving to a house without the possibility of a greenhouse, but never lost the interest.

Last Christmas, Debby asked what I'd like to have, you know, the typical question when you have already everything ... In short, I remembered a presentation I attended more than 15 years ago about the difficulty growing certain cacti like ariocarpus and aztekium from seed. I was very surprised back at the time: to me they just seemed small and slow but not more difficult than my usual kind of seedlings (mesembs, with a majority of conophytum), but I never attempted growing them. Having a bit more time now that the kids require less time of Taxi Daddy, Santa brought me a packet of ariocarpus kotschoubeyanus macdowellii seeds.

I've sown them mid February, sterilizing the substrate in the microwave. I added some supplementary sterilized water as well to ensure high humidity for the coming months. Subsequently I placed the pot in a glass jar, see picture: The jar was placed on the window sill at room temperature. Here they were exposed to full sun from 4pm onwards. Germination occurred within 2 weeks. After 4-5 months the first tubercles appeared. I've made a picture, but they're still in the jar, so not the best quality pic unfortunately. As you can see, some color already, the first spine/tubercle contrasting nicely. Note the impostor at the right...

After 6 months, my impression up to now is that they're as easy as the average Conophytum, slow but steady and certainly a lot easier than some of the Conophytum from section Cylindrata.
So far so good, but now I enter however unknown territory: How long should I keep them in the jar? Based on what I found on the web, people tend to open the bags after 3 months, but some keep them in for the first year. When opening the jar and taking them out, I know I'll have to adjust them gradually to the change of humidity.

Does anyone have advise? Iann, I know you grow all your plants like weeds, any recommendation?

Kind regards,
Tom Jacobs

I'm quite lazy & would leave in the jar until next year and they are bigger, taking them out really slows down the growth

Thanks Tina.

I have 2 follow-up questions:
1/ They're now in luxury, moist circumstances, whereas I used to grow my plants in a very harsh way (restricted watering, limited or preferably no fertilizer ever). Would such a long baggy/jar period potentially result in seedlings having difficulties to cope such circumstances later onwards?
2/ Most people tend to use plastic bags for sowing. These don't perfect close, hence one should from time to time open the bag and add sterilized water. The jar I'm using is sealing much stronger, so no need to open it every x weeks/months. In such closed environment, the amount of water, oxigen, carbon, nutritions etc is restricted. Could this in one way or another impact growth? I mean, growth means increase the number of cells. The seedlings require carbon and nutrition for growth, but these are restricted in this setting. Initially this would clear not be in issue given the nice germination and progress. But at a certain point it should, wouldn't it? Did anyone try a head-to-head comparison, for example, split a parcel of seeds in 3 and keep one pot closed for 3 months, one for 1 year and the third one closed for an undefined amount of time, conditional no algae would set off? I would be curious to see average diameter over time. To get a robust estimate/result, it would require a large enough number of seeds and seedlings of course. Potentially faster growing species would be a better choice, assuming they consume resources faster?

Bye,
Tom Jacobs

Ariocarpus are quite easy to grow, not sowing in glass jars is necessary. But now they are in there, just keep the glass jar locked until spring. If by that time the seedlings are still fine and the soil is moist, but there is no algae in there overgrowing the seedlings, I would probably keep the seedlings locked in longer. Right until all the moist has dissipated or the algae starts to overgrow, whatever comes first.

The 'growing in the jar' trick is mostly recommende for growing Aztekium, Blossfeldia and Strombocactus. I keep them in the jar for about one full year, sowing in spring and taking them out again at the start of spring the next year. Or if algae has spread too much before that time, of course (a little bit is not a problem, just as long as it does not overgrow the seedlings).

Once out of the jar, you will need to protect them for a few years as you might do with any <1 year old seedling. So no full sun, but also regularly watering them like any very small seedling (for me that is a weekly or biweekly soaking as for all my seedlings). At least until you are the size of a pea. Which might take quite some years for Aztekium!

Thanks Aiko,

Unfortunately someone else decided that it is time to open the jar by knocking it over... But fortunately the seedlings were not severely affected and are doing fine. They're growing faster than I expected having already a second tubercle within 9 months. They're not as difficult as one told me, or my benchmark is fairly different So indeed, I should have chosen for the aztekiums as a challenge.

Bye,
Tom

I don't think Ariocarpus are particularly difficult to grow from seed, but as you mention, they are quite slow. Maintaining constant warm (to hot) humid conditions for as long as possible helps. While they don't rot as readily as adults, they certainly can turn to mush in an instant, but it seems like soggy soil rather than high humidity is the thing to avoid. They cause more trouble for me *after* they come out of the humidity and I have to start watering them.