Is this Parodia ottonis unhealthy?

[loyall]

This P ottonis is 9cm in diameter and has blossomed for me for three years. I notice that the corking seems to be slowly progressing. Is this an indication that it is unhealthy? It also produced several small buds last fall. Soil is wet because I watered it yesterday.

P ottonis IMG_0242.jpg (79.84 KiB) Viewed 2567 times

[Tom in Tucson]

This "corking" condition is common in several genera, but the genus name (now passé?) that I prefer to use is Notocactus. The old genus name; Wigginsia, (Malacocactus) was infamous for this somewhat ugly (but harmless) appearance.

[loyall]

So Tom, do I correctly understand you to say that corking like this is typical of Parodia (Notocactus) ottonis?

[Tom in Tucson]

This section of what is now included in the genus Parodia often has this growth habit. Other genera from North America share it as well.

[Steve Johnson]

So Tom, do I correctly understand you to say that corking like this is typical of Parodia (Notocactus) ottonis?

For good or ill, everything starts out in the roots -- what you have is severe and premature corking caused by what appears to be potting soil. Mix it with some sort of mineral gravel for better drainage and aeration of the roots. The options are:

• Pumice -- IMO the best option. If you can't get it from a local nursery, you'll find a good selection of it on Amazon:
  https://www.amazon.com/s?k=pumice+for+p ... _sb_noss_2

• Crushed granite poultry grit.

• Calcined clay granules (AKA Leca balls), also available on Amazon:
  
  https://www.amazon.com/s?k=leca+balls+f ... doa-p_3_10

Pumice and calcined clay provide good aeration and drainage plus decent water retention, so I'll recommend a mix of 60% mineral gravel/40% soil, although I think you could tilt more in favor of the mineral side. If you decide to go with crushed granite, the ratio should be 50/50, but perhaps not the best option.

There are a few things you'll need to do. First, take the Parodia out of its pot. Second, inspect the roots and see if you have root mealybugs. If you don't know what they look like, go here for photographic examples:

https://www.cactiguide.com/cactipests/#mealybugs

Third, clean the soil out of the roots as thoroughly as possible. If you do have root mealies, soak the roots in a 2% soap solution with warm water for about an hour. (Plain dish soap is fine, insecticidal soap even better. Sterilize the pot with it too.) Regardless of whether you do or don't have root mealies, let the roots dry out completely. And last but not least, repot the plant in fresh, dry mix. Don't even think about watering until the roots of your Parodia start growing in spring.

It's helpful to know more about your situation, so I'd like to ask the following questions:

• Is this your only cactus? If not, how many cacti do you have? What are their species?

• Do you keep the cactus (or cacti) indoors our outdoors during the spring and summer?

• Are you fertilizing? If so and you give me the guaranteed analysis you'll see on the label, I can tell you if you have a fert that's right for cacti.

When it comes to cacti and succulents, all fertilizers are not equal. Not a priority at the moment, but I'll discuss this with you further if you'd like.

[MikeInOz]

You plant's photosynthetic area has been reduced by 50% or so. You can keep the ''corking'' down by growing the plant more quickly. Frequent repotting, feeding, water etc.

[Steve Johnson]

You plant's photosynthetic area has been reduced by 50% or so. You can keep the ''corking'' down by growing the plant more quickly. Frequent repotting, feeding, water etc.

I should also mention that premature corking can be reversed when desert cacti go from soil-heavy mixes to mixes with better drainage and aeration of the roots plus regular feeding with fertilizers that are suitable for cacti. I know because I've seen this in my own cacti going from the years when I didn't know what I was doing (1970-1991) to the more current years when I could see the difference between doing it wrong and doing it right.

[loyall]

Steve Johnson said, "I should also mention that premature corking can be reversed when desert cacti go from soil-heavy mixes to mixes with better drainage and aeration of the roots plus regular feeding with fertilizers that are suitable for cacti. I know because I've seen this in my own cacti going from the years when I didn't know what I was doing (1970-1991) to the more current years when I could see the difference between doing it wrong and doing it right."

You seem to disagree with Tom in Tucson that this kind of corking is typical of P. ottonis. I have read elsewhere that corking can be a normal part of aging as well as an indication of poor cultivation.

Steve further said, "There are a few things you'll need to do. First, take the Parodia out of its pot. Second, inspect the roots and see if you have root mealybugs."

Two weeks ago I repotted this cactus and I observed no mealy bugs. I use Bonide systemic houseplant insect control with Imidacloprid when I repot.

Steve asks what cacti I grow.

I have 17 window cacti, Parodia, Mammillaria, Ferocacti, Stenocacti, Echinopsis, Gymnocalycia, and Echinocacti. Although I doubt that you approve, I have had good luck for the past four years with a fast-draining over the counter soil mix. For now I am inclined to stick with it.

These cacti all live indoors in a heated room so they need water all year round. I drench and let dry every two weeks from mid-March through September, and every three weeks in the winter months. They all seem to be doing well. Six have blossomed. I was really only concerned about the corking on the ottonis.

Steve asks about fertilizer. I use Miracle Grow Succulent plant food, 0.5-1.0-1.0 every four weeks in the summer months in the watering pot. Ana in the Cactus Caffeine podcasts on Youtube recommends tomato fertilizer a half strength in the first spring fertilizing for super blooms. I was thinking of trying that this spring.

[Steve Johnson]

You seem to disagree with Tom in Tucson that this kind of corking is typical of P. ottonis.

I didn't disagree with him. Typical yes, but the extent of corking depends on whether the species is growing in the wild or being grown under cultivation. I made a point of observing the fact that your ottonis has severe and premature corking. If I'm wrong, so be it. If I'm right, you do have an indication of poor cultivation with the soil mix you're using. Which brings me to this...

Although I doubt that you approve...

Gratuitous comment and completely unnecessary. I have years of observational cactus experience knowing what works well and what doesn't work well or at all. If you 'd like my help based on that experience, fine. If you don't, just say so and I'll back out of this thread.

[Nino_G]

This P ottonis is 9cm in diameter and has blossomed for me for three years. I notice that the corking seems to be slowly progressing. Is this an indication that it is unhealthy? It also produced several small buds last fall. Soil is wet because I watered it yesterday.

I can tell you from a first-hand experience (I've had couple of P. ottonis in collection for more than a decade before I gave them away to make room) that they are NOT prone to corking at all.
I think your growing conditions are not adequate - like others already mentioned above. P. ottonis likes very permeable, quick-drying substrates (use mineral, well permeable substratum with little organic matter), they like well-lit and well-ventilated position (ideally outside) and, last but not least, they require period of dry and cold hibernation. I'd say that corking in your case is mainly consequence of slow drying substrate and inadequate ventilation.

[loyall]

Thank you Nino and Steve. I appreciate your helpful input.

[loyall]

Here is a photo from today March 21,2024 of my possibly unhealthy P. ottonis. To me, the three flower buds and the two pups suggest the plant is healthier than some have thought.

IMG_0244.jpg (84.28 KiB) Viewed 2078 times