Ariocarpus kotschoubeyanus

[PhiloCacti]

Since all the seeds of this species I ordered never germinate. I found a nursery in Germany. I ordered 4 Ariocarpus kotschoubeyanus v macdowellii to a friend in Germany.

My friend stayed in Germany for 4 weeks. She watered frequently in an attempt to help. Yesterday I went to pick these guys up. And one of the 4 was rotting from the roots.

IMG_20150727_085659.jpg (45.46 KiB) Viewed 4206 times

I washed the healthy 3 from the wet soil. Since the weather here is hot as hell, they dried up in 10 min. Even the soil that I emptied from their pots dried up in this time period as well. So I potted them again.

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To be on the safe side, I won't water them for a week and I'm also introducing them to the harsh sun here.

I did a few areol grafts, from whatever healthy tubercles that were left on the rotting specimen. I tried grafting Ariocarpus areols twice before but didn't succeed. But since this one's a goner, it wouldn't hurt to try.

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I also grafted a firm portion of the root and hopefully something is going to take.

Any advice for better caring for this species would be appreciated

This species is my favorite by far, so hopefully I'll collect all kotschoubeyanus variations, at some point in time.

On this website http://www.living-rocks.com/adult.htm, the author states that:
"In the wild all Ariocarpus, without exception, grow in a calcareous soil of some type, seemingly from choice. In most cases the calcareous material is limestone (calcium carbonate) although many populations of A. kotschoubeyanus grow on gypsum (calcium sulfate) mud silt flats, but some also on limestone"

Would it be a good idea to buy gypsum, and make a very diluted solution and water them with it?

[iann]

This is one of the most sensitive Ariocarpus to the sun. Go easy, and probably provide some afternoon shade even when they are adapted. Your plants look very "open", possibly having been grown quickly in low light, but might have been slightly scorched since then.

Soil is a controversial issue. I don't think any of the Ariocarpus are gypsum endemics, so I don't think many people use gypsum for them. Many people use limestone, but a few say it is "poison". You have the ideal opportunity to compare plants side by side in different soil of with different supplements in the water.

One thing you can be sure about is that they should never stay wet for too long. Many people use ridiculously free-draining soils to achieve this, probably to the detriment of the plants. They need to get good and wet when you water them, because as you've seen they have very few fine roots, but staying wet for too long will be fatal. Staying wet for several days is fine, necessary even, several weeks is not. Your pots are too big. The plants will never fill them, so you're relying on evaporation to save your life every time. It sounds like this might often work in your climate\, but you only have to water once when it isn't baking hot and they'll rot.

Be patient, they don't do anything quickly and I wouldn't even water them for several weeks after the treatment they've had.

[Onzuka]

You may also have them protruding a bit too far from the potting mix, mine have been in their pots for a long time and only the tubercle tips are really showing, although my plants are flatter than yours.

Steve

[PhiloCacti]

Would it be better if I burry them more in the soil?

Since I still haven't watered them yet, the soil is still loose. So I'm guessing it will compact and I can add limestone pebbles to burry them all the way up.

Thank you for the fast reply

[DaveW]

I would just bury them up to their previous soil level. Many of the tuberous rooted cacti have contractile roots that will pull them down into the soil if conditions dictate, that is probably why Steve's plants being potted for a long time have done so.

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http://www.amjbot.org/content/97/12/1951.full" onclick="window.open(this.href);return false;

Obviously it depends on the plants growing conditions, in kinder environments the plants will stay higher above the ground than in harsher ones.

An example of the contractile roots in Eriosyce (Thelocephala) odieri having pulled it down into the ground in the resting season in habitat flowering at the start of the growing season. Of course soil also blows over them in the resting season helping to protect them from desiccation.

odieri5.jpg (118.85 KiB) Viewed 4175 times

You can see by the crater around the right hand plant the space the body occupied when it was previously growing and turgid.

[forests-of-fire]

I have nothing helpful to say, but those are so pretty! Good luck with them.

[PhiloCacti]

Thanks a lot Dave, never new about these roots. Very interesting.

I'll re-pot them so they're at soil level.
Do you have any advice on watering them with gypsum diluted in water?

Forest - Thank you

[Saxicola]

This is one of the most sensitive Ariocarpus to the sun. Go easy, and probably provide some afternoon shade even when they are adapted. Your plants look very "open", possibly having been grown quickly in low light, but might have been slightly scorched since then.

Soil is a controversial issue. I don't think any of the Ariocarpus are gypsum endemics, so I don't think many people use gypsum for them. Many people use limestone, but a few say it is "poison". You have the ideal opportunity to compare plants side by side in different soil of with different supplements in the water.

One thing you can be sure about is that they should never stay wet for too long. Many people use ridiculously free-draining soils to achieve this, probably to the detriment of the plants. They need to get good and wet when you water them, because as you've seen they have very few fine roots, but staying wet for too long will be fatal. Staying wet for several days is fine, necessary even, several weeks is not. Your pots are too big. The plants will never fill them, so you're relying on evaporation to save your life every time. It sounds like this might often work in your climate\, but you only have to water once when it isn't baking hot and they'll rot.

Be patient, they don't do anything quickly and I wouldn't even water them for several weeks after the treatment they've had.

I think the timing of the watering is part of why people are so scared about them rotting. I don't have any problems in the summer watering them like a normal cactus, but in the winter I keep them bone dry. They really don't like being wet when they are dormant. That may have led to a belief that they never want much water.

[PhiloCacti]

This is one of the most sensitive Ariocarpus to the sun. Go easy, and probably provide some afternoon shade even when they are adapted. Your plants look very "open", possibly having been grown quickly in low light, but might have been slightly scorched since then.

Soil is a controversial issue. I don't think any of the Ariocarpus are gypsum endemics, so I don't think many people use gypsum for them. Many people use limestone, but a few say it is "poison". You have the ideal opportunity to compare plants side by side in different soil of with different supplements in the water.

One thing you can be sure about is that they should never stay wet for too long. Many people use ridiculously free-draining soils to achieve this, probably to the detriment of the plants. They need to get good and wet when you water them, because as you've seen they have very few fine roots, but staying wet for too long will be fatal. Staying wet for several days is fine, necessary even, several weeks is not. Your pots are too big. The plants will never fill them, so you're relying on evaporation to save your life every time. It sounds like this might often work in your climate\, but you only have to water once when it isn't baking hot and they'll rot.

Be patient, they don't do anything quickly and I wouldn't even water them for several weeks after the treatment they've had.

I think the timing of the watering is part of why people are so scared about them rotting. I don't have any problems in the summer watering them like a normal cactus, but in the winter I keep them bone dry. They really don't like being wet when they are dormant. That may have led to a belief that they never want much water.

Good to know that. I water all my cacti about 2-3 times a week. My Lophophoras even split a lot cuz of that.

[greenknight]

If you can't find the deep, narrow pots needed to provide space for the tap roots without over-potting, you could take up the excess space in those pots with rocks. Put some fairly large rocks in the bottom of the pots next to the sides, leaving an opening in the middle to accommodate the tap root.

You should never have a distinct layer of gravel in the bottom of a pot, that actually impedes drainage, but you can use rocks to reduce the volume of a pot as long as your potting mix goes all the way to the bottom of the pot in places to provide drainage channels.

[HP22B]

I had good success with germination of A. kotschoubeyanus just in the past two weeks with the baggie method. Daytime temps were kept around 25-35C with night temps of about 18C. 12 hour days under a 150W tube CFL (in a propagator tank for seedlings). I had germination in about three days after the seeds were sown.

[DaveW]

How often you water depends on your climate and how fast the potting soil dries out. Watering 2-3 times a week would be too often in the UK, but probably not in hotter sunnier countries. That is one reason we cannot give advice on cultivation that applies to all countries, apart from the usual advice to let the potting soil dry out between watering's so the roots don't permanently stand in water.

[PhiloCacti]

This is one of the most sensitive Ariocarpus to the sun. Go easy, and probably provide some afternoon shade even when they are adapted. Your plants look very "open", possibly having been grown quickly in low light, but might have been slightly scorched since then.

Soil is a controversial issue. I don't think any of the Ariocarpus are gypsum endemics, so I don't think many people use gypsum for them. Many people use limestone, but a few say it is "poison". You have the ideal opportunity to compare plants side by side in different soil of with different supplements in the water.

One thing you can be sure about is that they should never stay wet for too long. Many people use ridiculously free-draining soils to achieve this, probably to the detriment of the plants. They need to get good and wet when you water them, because as you've seen they have very few fine roots, but staying wet for too long will be fatal. Staying wet for several days is fine, necessary even, several weeks is not. Your pots are too big. The plants will never fill them, so you're relying on evaporation to save your life every time. It sounds like this might often work in your climate\, but you only have to water once when it isn't baking hot and they'll rot.

Be patient, they don't do anything quickly and I wouldn't even water them for several weeks after the treatment they've had.

Hey iann, sorry for the late reply.
Now they're getting 3-4 hours of morning sun. I won't water them until I feel they've settle. I'll probably try the gypsum water on one of them and see if it'll make a difference.

I'm in North Africa so it's pretty hot here. So I'll only water them once a week until the end of the season and no water in the winter, which is 3 months max.

[iann]

You'd be better changing the soil if you feel the need to water 2-3 times a week. Maybe even using a bigger pot. No cactus in the world gets rained on 2-3 times a week, no matter how hot or sun the conditions. If there is any species that needs the exact opposite treatment, it is Ariocarpus. They don't live on nightly fog, they live on very occasional floods. I still don't like suggesting a pot bigger than the roots, no point having wet soil where the roots *aren't*, but if the soil dries out so fast, use a heavier soil and put on a top dressing. You can see there are no feeder roots in the top half of the taproot so it might as well be sitting in dry grit, with the rest in a dense soil that will stay wet for a few days. Don't under-estimate the power of a top dressing to reduce evaporation, maybe try it and see if you can reduce your watering frequency.

[Saxicola]

Are you sure the pots are drying out that fast, or are you just checking the top of the soil? I know N. Africa can get hot in the summer, but not really much different than Southern Arizona temperature wise. People there aren't watering cacti that often.