Help with growing Ariocarpus fissuratus from seeds

[Ksenija87]

Hi there,

this is my first time growing cacti from seeds, and while with other 'families' as Ferocactus or Astrophytum is going pretty well, with this one I'm puzzled.
The plantulae have grown almost 15 days ago thorns and we're doing great, but in the last 5-6 days they've collapsed (see photos). I planted them in a mixture of 20% cactus soil and 80% river sand; I do water them 2 times a week after they got dry.
Did I do something wrong or it has to be like this?

My bests,

Francesca

[greenknight]

Too much light, not enough moisture. Check out Hanazono's thread on growing Ariocarpus from seed -

http://www.cactiguide.com/forum/viewtop ... 16&t=36913

According to him, Ariocarpus should be light green - too much sun and they turn reddish-brown (like yours), their growth is suppressed, and it takes months for them to recover. He keeps them in soft light and high humidity for the first few years, and gets excellent results.

All cactus seedlings should be kept constantly damp for the first few months, but not too wet - instead of watering twice a week, you should give them a daily misting. Ariocarpus seedlings need more coddling than most, while Ferocactus seedlings are among the toughest and most tolerant.

[Ksenija87]

Thanks a lot for your reply. Oh shoo, I knew there was something wrong... See if I can save them, I hope...
I suppose no fertilizer for a while, right?

Francesca

[adetheproducer]

I wouldn't bother with fertilisers there is very little requirement for organic nutrients with most cacti. If there are organic soils in you mix which is likely, as you said it's part cactus soil, there will be more than enough fertilisers already in the soil adding more could do more damage than good.

[Ksenija87]

Hi, thanks for your explanation: yes, it's pretty rich, not only due to the cactus soil, but the sand it's a special one: we had the river's flood last November, so it's like a sort of slime.
Guys, I take advantage of your advices, and I'd like to know with how many degrees should the grow and if it's better to place them in small greenhouse to keep humidity, temperature etc.

Bests!

Francesca

[adetheproducer]

Check the stone eaters issue here

www.xerophilia.ro

That's a good resource for mixing soils and have a nose through the rest of the issues there is one with an article specifically about ariocarpus which is a good read too.

[Ksenija87]

Thanks, I check right now!

Bests,

Francesca

[greenknight]

Ariocarpus fissuratus is native to Mexico and south Texas, it definitely likes heat! Ferocactus and Astrophytum do, as well. There are few cacti that don't like it hot, Oreocereus is one that comes to mind.

A greenhouse would be a good place for your cactus seedlings, certainly.

[Ksenija87]

Thanks for your answer. I asked about the greenhouse because we're having the coldest abd wettest spring ever. I'll build myself one, in the meanwhile I keep them in the window's sill with little light.

Bests!

Francesca

[greenknight]

You're welcome, happy to help.

Too little light is also bad, of course, some trial and error may be involved. Seedlings that get too little light grow etiolated - pale, thin and stretched. Light to medium green, maybe with just a slight reddening, is what you should aim for. Ariocarpus that are actually growing have projecting tubercles - long, conical projections with a star-like cluster if spines on the end - don't mistake that for etiolation.

[Ksenija87]

Thanks for your reply. Yes, of course, if you don't make mistakes you'll never learn. What about direct light just in the morning (like from 8 a.m to 11 a.m)? I used to put them in the south side of the house, where they got more light, but as you've seen they burned. Now I placed them north, where they get a soft light. So far I'm following your advice, so water every day, around 22 °C degree all day and night; of course it's early to see changings, they're like meditating, I hope we'll come to the point they're moving and projecting out their tubercles.

Francesca

[greenknight]

They may meditate for quite a while before anything happens. They're not the worst I've seen, though - at least they still show some green, they're not entirely purple.

Avoid any direct sun for young seedlings. unless it's filtered through some kind of shading like a sheer curtain - I've used tissue paper for shading with good results. Once they begin to look more like miniature versions if their adult selves you can gradually introduce them to sun, starting with the morning sun - this will be much later for the Ariocarpus than the others. It's also best to switch to bottom watering when they're a few months old, which encourages deep root growth. I use the sprayer for this, too, just direct it at the base of the pot - this allows you to meter the exact amount of water they get by counting the squirts. As long as they're not sitting in any depth of water, though, they won't get too wet this way.

Commercial growers automate that process with capillary mats. The mat draws water from a trough and stays constantly moist, and pots sitting on the mat remain uniformly damp. You could get that for your greenhouse, if you want.

[Ksenija87]

Thanks for your answer, which I literally noted down
I do have something similar to a paper curtain, though is a white a-like cloth, we use it in winter time to prevent outdoor plants from be killed by frost. About watering, I've been using since they pop out bottom watering, this morning I tried with the sprayer. I also think I got why've turned into purple. I use to let seedlings grow by covering the small pots with film; after they're born, I cut the film to let the soil dry a little, and... I let the pot too much on the direct light, so they got burnt. While for Ferocactus nothing happened, with those ones, which are so delicate, it caused the pretty mess you've seen.
By the way, one of them it's turning into sort of intense green; the one with the collapsed thorns still not giving life's signs.

Francesca

[greenknight]

They're not really burnt, just stressed. It sounds like that one is coming out of it already.

[Ksenija87]

Sorry, but just one week with my boyfriend, and the Ferocactus grew this reddish spots... What is it? Too much sun?
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