Black spots on my Parodia magnifica.

Trouble shoot problems you are having with your cactus.
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WayneByerly
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Joined: Sun Apr 06, 2014 10:35 pm
Location: In the north end of the Sequachee Valley, 65 miles north of Chattanooga Tennessee USA. Zone 7a

Black spots on my Parodia magnifica.

Post by WayneByerly »

As long as the temperature of the greenhouse did not fall below what I thought to be minimum temperatures, I did not much concern myself with what was going on in the greenhouse. But looking at two pictures of a cacti today brought two questions to my mind, only 1 of which I will address here. My Parodia magnifica, and the black spots that I found on it today.

Does this cactus have something wrong with it? The shriveled look I am quite willing to attribute to a lack of water. It looked similar to this when the cool weather started, and only looks more wrinkled and withered now that it has been without water for months. On the off chance that threre is something wrong with it that I could do something about, I brought it in "out of the cold" today.

The five pictures I've included here are 1 "normal" focus picture ...
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Parodia magnifica (1).jpg
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... and 4 pictures where I have "zoomed in. Any information regarding what I might do to save this cactus if it DOES have some affliction, will be greatly appreciated.
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Parodia magnifica (2).jpg
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Parodia magnifica (3).jpg
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Parodia magnifica (4).jpg
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Parodia magnifica (5).jpg
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Make the moral choice & always do what's right. Be a good example. Be part of the solution & make a contribution to society, or be part of the problem & end your life with nothing but regrets. Live a life you can be proud of! Zone 7a
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ElieEstephane
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Re: Black spots on my Parodia magnifica.

Post by ElieEstephane »

It looks too shriviled for relatively little time in hibernation. IMO opinion it is probably parodia warasii which in my experience is very prone to rot.
I've had similar spotting in some of my cacti and it was due to lack of air circulation. Keep an eye on them and see if they spread.
There are more cacti in heaven and earth, Horatio, than are dreamt of in your philosophy.
One of the few cactus lovers in Lebanon (zone 11a) :mrgreen:
esp_imaging
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Re: Black spots on my Parodia magnifica.

Post by esp_imaging »

WayneByerly wrote: Sat Jan 27, 2018 2:38 am As long as the temperature of the greenhouse did not fall below what I thought to be minimum temperatures, I did not much concern myself with what was going on in the greenhouse.
So what have your minimum temps been? Were these from a prolonged cold spell, or just brief daily dips?
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WayneByerly
Posts: 1240
Joined: Sun Apr 06, 2014 10:35 pm
Location: In the north end of the Sequachee Valley, 65 miles north of Chattanooga Tennessee USA. Zone 7a

Re: Black spots on my Parodia magnifica.

Post by WayneByerly »

esp_imaging wrote: Sat Jan 27, 2018 1:42 pmSo what have your minimum temps been? Were these from a prolonged cold spell, or just brief daily dips?
The short version of the answer to your question is that it was a single brief dip to as low as 29. But in order to provide as much information as possible, to answer your question fully, I'll say the following.

I have a thermostat that controls a small space heater that I keep inside the greenhouse. It comes on when the temperature reaches a low of 40 and goes back off at 45. This way the cacti experience a cold season, but don't suffer from freezing temps.

I did however once have the temperatures in the greenhouse drop as low as 29 when I discovered that the heater was incapable of maintaining a low of 40 when ambient temperatures dropped below 20. That killed one of my euphorbia and caused me to have to cut some top edges off another. But I didn't see any cacti suffer from that brief dip into freezing temperatures.

I will note however that the humidity has been rather High in the greenhouse because I have no way to heat it and vent it at the same time. Rain invariably seeps under the edge of the greenhouse after a rain, and the slightly warmer temperatures cause the water to evaporate and then condense on the inside of the greenhouse.

In providing the pictures that I posted with this question, I had to rely on a slightly older picture, about a month old, to show you the yellow color. I did this, because when I brought the parodia inside and took a photo of it, the lighting provided a different shade of green... More green and less yellow.

I acquired this Parodia and it suffered from a rather bad case of etoliation as it was being grown in a windowsill and was not getting near the amount of light that it wanted. This Parodia also had a nice-sized offset on one side. So I cut the top off of the Parodia and cut the offset off the main body of the parent and replanted both. And both have been living in the greenhouse since. The offset is growing like you would expect a parodia to grow. A short globular cacti. But the offset has grown like you see in the picture. Like a semi columnar cacti.. I don't know why the two pieces should have grown so differently.

Here's a foto of both of them:
Both Parodia.jpg
Both Parodia.jpg (119.94 KiB) Viewed 395 times
Make the moral choice & always do what's right. Be a good example. Be part of the solution & make a contribution to society, or be part of the problem & end your life with nothing but regrets. Live a life you can be proud of! Zone 7a
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