Is corking a sign of dormancy?

[widea]

Hi,

After 8 months of being completely white and corked, my cactus seems to wake up after I put it outside:

Luckily I did not throw it away.

Is this corking a sign of dormancy, to protect itself from something? If not, what could it be?

[ElieEstephane]

Corking of all of the stem is very unnatural and could be the result of a pest attack or maybe a sunburn. Your cactus is starting to grow again on its reserves. Be VERY careful so the green growth doesnt get sunburned. It's the only thing it has got to help it grow

[widea]

Be VERY careful so the green growth doesnt get sunburned.

I will, thanks!

[DodoBrooke]

Something similar is happening to my little Polaskia. She is like only 5cm and already corked and looking sick.
She has new growth now. I have read it can tolerate sun well that’s why I suppose could not be sunburn

46732F2F-B63F-42CB-9497-8F19FCEF8055.jpeg (65.54 KiB) Viewed 2256 times

[ElieEstephane]

Something similar is happening to my little Polaskia. She is like only 5cm and already corked and looking sick.
She has new growth now. I have read it can tolerate sun well that’s why I suppose could not be sunburn 46732F2F-B63F-42CB-9497-8F19FCEF8055.jpeg

While cacti are pictured growing in the most arid environments in the harshest sun, keep in mind some points:
- Young cacti such as your polaskia often grow under nurse trees to provide shade for them or they would cook to death
- Even if a cactus can take full sun, coming from the nursery it has never really seen full sun. They grow under some shade and are given lots of fertilizer which means their skin is fragile. You need to acclimate them slowly
- Full sun in the house is not the same as full sun outside so moving briskly outside is a guaranteed way to scorch your cacti. In addition, lack of ventilation accelerates a sunburn

[widea]

I find it strange that my two cacti got corked in the first place:
- they were inside all winter with moderate light
- the other cacti nearby did not get this corked skin so that rules out bugs (imo).
That is why it got me thinking of some kind of dormancy (winter, less light, almost no water).

[ElieEstephane]

It's definitely unnatural. While i rule out bugs too, they can be selective sometimes.

[phil_SK]

Corking is a natural ageing of the skin, akin to bark formation on a previously green twig of a tree or shrub. Anything that happens on newer growth isn't corking in this sense. Both of these photos look like mite damage to me. As the plant comes out of dormancy/produces new growth, then that new growth will be undamaged.

[widea]

I never saw mites but I read they are almost too small to see. And when the damage has done they are already gone, correct me if I am wrong.
They must be very selective because they did not touch the other plants (orchids and other cacti).
But the next winter when my cacti go inside I will check occasionally for mites. Perhaps I am on time to spot them. Doing something about it when I see them is part two...

[greenknight]

You need a strong magnifier to see the mites. Red Spider Mites make silk like tiny spider webs, you're more likely to see that than the mites themselves. There are other mite which don't make silk, though.