Stopping Ariocarpus flowering

[Nick_G]

I've had half a dozen or so Ariocarpus die this winter. Not rot as we normally see it, starting in the roots and spreading upwards, but a collapse of the plant body with easily detached, dried up tubercles. The roots were sound on all of them. Although my greenhouse isn't heated at all this hasn't been a cold winter, so I don't think that cold is to blame. The one thing they all had in common was that they had flowered in 2020 and mainly late in the autumn in November. I think mould from the old flowers is the culprit. So how can I prevent them from flowering? I've noticed before that if Ariocarpus are grown in half shade they grow well, don't etiolate, but are reluctant to flower as well. I'm going to move them from the brightest spot in my greenhouse to a shadier location and see what next autumn/winter brings. Any thoughts?

[Tina]

Cant really help but some of mine still had buds very late in the year so I actually cut out the flowers taking as much flesh as possible. No heat at all ?
Wouldn't the sunnier spot be better but be ready to remove spent & half formed buds.
This should be interesting what we all would do in your situation.

[Terry S.]

This is always a danger with ariocarpus plants and last autumn was more problematic than usual. The flowering started early and then went on well into November. This was at a time when we had mild but very humid weather. I remove all dead flowers as soon as I can, but this only works for the early flowers. The ones that flower late get brought in on a house windowsill as soon as flowers have faded. It only takes about a week there before they are dry enough to be removed and the plants returned to the greenhouse. Tricky if you have a lot to cater for.

Many of us used to buy 5 - 8 year old plants from continental raisers but that is now almost impossible unless you want to resort to smuggling and inciting the wrath of the CITES police for importing appendix I plants. Remember how they made publicity over the Astrophytum asterias seedlings that they intercepted last year? So we really need to look after what we have here in GB.

[Nick_G]

I find dried Ariocarpus flowers to be very persistent and difficult to remove. I'm always worried that I'm going to damage the plant. Any special technique or just a good yank?

No, no heat at all Tina, I haven't heated my greenhouse for probably 15 years now, I decided it was just a big waste of money.

[Terry S.]

If the flowers are dry, they come away fairly easily using a pair of tweezers.

Some heat in the greenhouse during the autumn, would have tended to lower the relative humidity and give a bit of protection from the botrytis problem.

With the earlier finish to flowering of arios in the autumn of 2019, coupled with not quite such high humidity, I don't think I brought any indoors. But 2020 was rather different.

[iann]

I've had Gymnocalyciums do this, they don't know when to stop flowering in the autumn. Botrytis set in on the dead flowers, which is almost inevitable in the wet autumns here, and had a free path into the plant body. Haven't had it happen on Ariocarpus, but can well imagine it might.

[Pattock]

Isn't air movement rather important in avoiding botrytis?

[iann]

Isn't air movement rather important in avoiding botrytis?

It helps.

[Nick_G]

well it looks like I have a few options:

1/Move them to a less sunny spot to try to inhibit flowering. I did this yesterday but I don't really like where they are. I can't see them that well and if you can't enjoy the plants on a daily basis what's the point in keeping them. I'm not a hoarder.

2/ Surgery as Tina recommends. Doesn't this still leave a fleshy remnant that could still rot?

3/ Move them inside as Terry does until the flowers have dried. I probably have too many.

4/ Not worry about it and accept the losses. This is my normal attitude towards my plants, a healthy one I think, but it would be a shame, they're nice plants and I'm sure other growers would like to have them.

5/ Drastically reduce the size of my collection so that I can care for them individually, overwintering any in the house as necessary in small enough numbers that won't irk my wife too much. I have quite a few grown from seed in the last 16 years, most about 10 years old that are just starting to flower regularly. I'm quite attached to the 16 year olds, they've done well for me, a couple are in 8 inch bowls now and they''ll definitely be coming inside for a while next autumn.

I think number 5 is the best bet. Selling Ariocarpus isn't so easy now of course with Brexit and I have received warnings from eBay recently about listing Cites 1 plants, they're not allowed apparently.

[MatDz]

What about a mix of 4 and 5? Just bring in the ones you care about, and let the fittest of the rest survive "in the wild"?

I'm surprised by the eBay and CITES issue, were you offering them international maybe?