Ariocarpus stopped growing

Trouble shoot problems you are having with your cactus.
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Hanazono
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Ariocarpus stopped growing

Post by Hanazono »

Ariocarpus grow slowly but they do not stop to grow when they were young.
One young retusus stopped growing and I removed it from the pot and inspected roots.

Photo 1: a normal young retusus and the retusus stopped growing
Photo 2: Roots of the retusus
I could not see any fine roots which rotted out. I cut parts of tap-roots and checked rotting. Tap-roots were alright.
I checked 3 more retusus which also stopped growing. I found they all lost fine roots as same.

I think retusus lost fine roots can survive but they can not grow. I have to reroot 4 retusus.
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Minnesota
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Re: Ariocarpus stopped growing

Post by Minnesota »

Good Evening, Frank,

As you go along with the reroot, I would be very interested to know what your actions are. Having read your extensive experiences, I would also like to know what you think the causes are when you have thought about this. I have two roughly the same size that are showing the same conditions, and I would like to learn more.

Thanks for sharing--the photos are very helpful.

Bret
Download
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Re: Ariocarpus stopped growing

Post by Download »

We've had a very wet Spring in Adelaide so far, so I'm not surprised to hear of losses or issues.

What do you do when trying to reroot them? Just leave them be or help them along with rooting hormone? Will you take preventative action like fungicide? I just bought some more fungicide to give my cacti a spray with as a preventative measure.
Minnesota
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Re: Ariocarpus stopped growing

Post by Minnesota »

Download wrote: Wed Nov 16, 2022 2:57 am We've had a very wet Spring in Adelaide so far, so I'm not surprised to hear of losses or issues.

What do you do when trying to reroot them? Just leave them be or help them along with rooting hormone? Will you take preventative action like fungicide? I just bought some more fungicide to give my cacti a spray with as a preventative measure.
Would the wet Spring include cooler temps as well?

Bret
Download
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Re: Ariocarpus stopped growing

Post by Download »

Minnesota wrote: Wed Nov 16, 2022 3:06 am
Download wrote: Wed Nov 16, 2022 2:57 am We've had a very wet Spring in Adelaide so far, so I'm not surprised to hear of losses or issues.

What do you do when trying to reroot them? Just leave them be or help them along with rooting hormone? Will you take preventative action like fungicide? I just bought some more fungicide to give my cacti a spray with as a preventative measure.
Would the wet Spring include cooler temps as well?

Bret
Yep.

Average low for October is 11.7 degC and we dropped below that 11 out of 31 days, in some cases only a degree or two above the record October low. Rainfall was 50mm for October, average is 44mm, except that the rainfall was spread out over most of the month, so everything stayed wet for ages.

Here in November, we've exceeded out average monthly rainfall (where I live we have doubled it) despite being only half-way through the month, and again temperatures are below average.

Mild weather is great in summer where it can easily go past 40 degC, but not so much in spring.
DaveW
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Re: Ariocarpus stopped growing

Post by DaveW »

From the difference in colour of the one on the right it certainly looks stressed. My Ariocarpus stopped growing for a time until I changed the potting soil they were in and then they started again. Loss of feeding roots if the plant is not rotting usually means they don't like the potting mix they are in, usually because of its PH. It may be the potting mix you are using or simply because salts have built up in it from fertilisation over time. The simple way is just to repot and see if that helps or use a new mixture.

Some growers like a little limestone in the mix whilst some say they grow OK without it. But never use garden lime = calcium hydroxide.

This is one recommendation for their culture.

"Limestone soils are, therefore generally slightly on the acid side of neutral to slightly on the alkaline side of neutral (pH7.0)."

https://living-rocks.com/adult.htm

And another view.

https://www.rrm.me.uk/Cacti/Cactus%20an ... linity.pdf
LateBloomer
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Re: Ariocarpus stopped growing

Post by LateBloomer »

I don't have much experience with ariocarpus only had a few over the years... from my experience I actually think it has to do with light intensity and heat.

This may be completely wrong since you do an amazing job growing very low light for the first few years and get fast growth but in my very limited experience with ariocarpus (seedlings purchased not from seed) if I didn't provide full sun and lots of heat (from sun exposure) the seedlings wouldn't grow at all. Everyone has different sun exposures/intensities but this was in South Florida from morning sun until around 1-2pm it had full sun during the summer. I would even mist the ariocarpus during very hot days which seemed to increase growth rate and never resulted in rot.

Again very limited experience and they are all in your greenhouse so maybe just weaker genetics?
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Hanazono
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Re: Ariocarpus stopped growing

Post by Hanazono »

Thanks everybody for giving comments.
I would also like to know what you think the causes are when you have thought about this.
5 same aged retusus sit on a plastic pad. Just one of them has the problem. I think the problem comes from lost fine roots but I am not sure the cause of lost fine roots, just one of them. I will try some anyway.
What do you do when trying to reroot them?
I will not use both rooting hormone and fungicide. I will use a rooting medium and changing watering way for a while until developing new roots.
I have experienced rerooting of retusus aroung 30 samples in total.
1. Rerooting of degrafted retusus: no tap roots, no fine roots
2. Rerooting of retusus off-sets: no tap roots, no fine roots
3. Rerooting of retusus test, cutting off tap roots, a shot taproots, no fine roots
I think the situation is similar to case 3.
Loss of feeding roots if the plant is not rotting usually means they don't like the potting mix they are in, usually because of its PH.
I checked PH.
1. water: 6.95
2. Old potting mix collected from the pot: 6.95
3. New potting medium (pumice sand): 6.95
Wet mix is used for cases 2 and 3 which showed same as water.
All results are acid slightly.

I will repot them with new potting mix. I also try to get limestone.

Frank
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jerrytheplater
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Re: Ariocarpus stopped growing

Post by jerrytheplater »

Frank, you might want to try to find dolomite gravel in a tropical fish store selling marine fish. Good source of Ca and Mg.
Jerry Smith
Bloomingdale, NJ
45 inches (114 cm) rain equivalent per year, approx. evenly spread per month
2012 USDA Hardiness Zone 6b: -5F to OF (-20C to -18C) min.
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greenknight
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Re: Ariocarpus stopped growing

Post by greenknight »

It's just depressed about the ugly pot you put it in. Put it in a nicer pot, and tell it what a pretty cactus it is.

Seriously - if you had to reroot 4 of them, maybe you do need to tweak the mix you use for Ariocarpus.
Spence :mrgreen:
keith
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Re: Ariocarpus stopped growing

Post by keith »

I think the problem comes from lost fine roots but I am not sure the cause of lost fine roots "

Change soil try again as long as its not rotted it should recover. Maybe dampness from humidity caused this ?
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jheaton
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Re: Ariocarpus stopped growing

Post by jheaton »

greenknight wrote: Thu Nov 17, 2022 6:32 am It's just depressed about the ugly pot you put it in. Put it in a nicer pot, and tell it what a pretty cactus it is.
LOL, that is exactly how I raise all my cacti !! Too funny.
Location: Salt Lake City, Utah, USA
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Hanazono
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Re: Ariocarpus stopped growing

Post by Hanazono »

G'morning Jerry, greenknight and keith,

Thanks for you comments.
you might want to try to find dolomite gravel in a tropical fish store selling marine fish.
I used dolomite gravel before. There is a product of crashed dolomite. I removed fine and used gravel only.
It seems 20kg bag is avilable and I will check.
It's just depressed about the ugly pot you put it in. Put it in a nicer pot, and tell it what a pretty cactus it is.
The pot is a standard round pot for the propagation purpose sold in here.
I use special pots for the cacti which I think there are ornamental value. Unfortunately the retusus on the photo has not ornamental value yet, still propagation stage. The retusus is 12 cm in diameter in 12.5 cm standard propagation pot.

Since I could not find special pots in Australia, I imported 2 types pots from Japan.
One type is Orchid pot and the other is U-pot. Photos are attached for your information. I imported 150 pos in total.
Problem is number of retusus. I have kept around 300 retusus in propgation pots which similar size to the retusus on photo. I have to import 300 pots additionally.
Change soil try again as long as its not rotted it should recover. Maybe dampness from humidity caused this ?
Winter in here is from June to August. I stop watering during these months normally.
Since weather in this year was not so good, I stopped watering in mid of May and restarted in mid of September.
It is mid of November but the temperature is not high enough. The maximum temperature should be more than 30 'C but it is less than 20'C actually.
I will chande soil.

Frank
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Download
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Re: Ariocarpus stopped growing

Post by Download »

Hanazono wrote: Thu Nov 17, 2022 1:09 am I also try to get limestone.

Frank
If you look in Mitre 10 or an agricultural supply store, you can buy bags of shell chicken grit. It comes in a big blue bag. Like limestone it's mostly calcium carbonate.
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Hanazono
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Re: Ariocarpus stopped growing

Post by Hanazono »

G'morning Download,

Thanks for your information.
you can buy bags of shell chicken grit.
I will try to buy shell grit.

Frank
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