Etiolation reversal

[AlanW]

I have a mammallaria hahniana cluster that I bought in a local hardware store. A nice plant but it is showing signs of mild etiolation. Do members think this might be reversable if given good growing conditions in the coming season?
Many thanks for any advice

[Aiko]

Could grow out of it, but not after many years. Really many years, for most global plants. And depending on the grade of etiolation. Do you have a picture?

[AlanW]

Thanks Aiko. I haven't got a photo of it yet. Will take some when the weather improves

[AlanW]

Hi folks. Have taken photo. What do you think?

[toadstar]

It doesn't look too bad. Got a side view?

[greenknight]

Agreed. Just be careful not to sunburn it, gradually increase its sun.

[AlanW]

Thanks for your advice. I have attached a side shot-not the best photo I have ever taken but it might give you a better idea

[greenknight]

Should be fine. With severe etiolation, you get thin, elongated growth - but this is not noticeably misshapen. The main problem, as I said, is it's vulnerable to sunburn.

[DaveW]

Usual etiolation from being in low light conditions in UK hardware stores, although not too bad in your case. As Spence says just acclimatise it gradually to stronger light so it does not burn. One problem we can get after the lower light levels in winter in the UK is in Spring with any strong sunshine the plants can burn unless you are careful.

[AlanW]

Thanks for your help & advice. Very encouraging

[AlanW]

One last question on this. How would I recognise sun burning? I now have it where it gets afternoon sun although it is still dry & in hibernation

[toadstar]

You'd see pale green and yellow spots or splotches form on the sun exposed side around the ribs and tubercles.
I have my cacti positioned so that they get some shade in the summer afternoon when it's 30+ C degrees out.

https://cactiguide.com/article/?article=article4.php
There's quite a bit of it in this pic here but if you catch it early enough then the cactus can heal itself.


I'm not sure how much you'd have to worry about that in the UK though.

[AlanW]

Thank you for that advice. No it rarely gets to 30°c in uk

[DaveW]

Sunburn can also be caused by rotating plants to keep them symmetrical. Nobody turns a plant in habitat, therefore they get used to sun from one side and often turning the opposite more tender side to the sun can cause it to burn. Of course it depends on how long one side has always faced the sun compared to the other in shade. But is something to watch out for if you are moving open ground plants to a new location, therefore it is best to mark the sun side and to try and plant them with the same orientation.

In the greenhouse I always use the plant label as a guide to which side faced the sun and try to put the label back on the same side when repotting. We may not get 30C much in the UK Alan but plants in our greenhouse don't get the same cooling free air movement as plants outside therefore may burn at lower temperatures.

[greenknight]

I live in a climate very similar to the UK, yet I managed to sunburn an Echinocereus pentalophus - a species from Texas and Mexico that can take blazing desert sun. This is a plant I grew from seed, and I moved it outside in the Spring to the same position it had been in the previous year, never imagining there could be a risk of burning it - but there was a sudden, unusually early warm spell, and some of its stems got badly scorched. It had lost its acclimatization to the sun over the Winter, though it wasn't visibly etiolated.

It's the sun right around noon you need to be most careful of. Afternoon sun is good for getting it re-acclimatized, as long as it's not too early in the afternoon.