Cattleya Walkeriana leaves problem

[Agnes]

Hello

I have problems with my walkeriana leaves. First it began with Kenny, when leaves started getting yellowish with dark green spots which is blooming now and the plant grows new roots. Two days ago I noticed the same problem with my other walkeriana (tipo) right now just one leaf. I grow them under led light, water and fertilizer every 3 days (Peter Excel calMag 100-120 ppm) I use demineralized water. Every two weeks I add some extra epsom salt 20ppm. I don't know if it is a fungus or bacterial infection or something else. I love walkerianas and growing them in my climate is pretty difficult. I don't want to lose them

I would be very grateful for any help

[estación seca]

Welcome to the Orchid Board!

That is a beautiful setup, and you're obviously a good orchid grower. I suggest you use the Search feature above in the maroon menu to look up this species.

This is a post here by catwalker808, from H&R Nursery in Hawaii, about growing walkerianas:
C walkeriana - Tips for Growing & Blooming - Orchid Board - Most Complete Orchid Forum on the web !

Have a read and think about how this compares to what you're currently doing.

[isurus79]

Looks like natural die off of old leaves. Was it more severe with Kenny?

Also, those fertilizer amounts seem pretty high for winter growing. What part of the world are you in?

[Agnes]

Stephen,

I live in Europe Poland. Almost no sunshine during winter months, middle of May I put all my orchids outside where they stay till the end of September. Right now all leaves of Kenny look really bad although the plant is blooming(two beautiful fragrant flowers) and growing new roots. The other walkeriana has also new roots and a new growth not sure if it is future flower. How much should I fertilizer during winter time? I try to follow Rick's advice from his youtube films, in nature plants always get some nutrition. I grow all my plants in lava rock and river rocks so they dry quickly.
I admire your orchids watched all your youtube films.

[isurus79]

Good to meet you! During winter, I usually don’t fertilize at all. If you really want to fertilize, I’d go for half of what you’re giving the plants. Here is a really great source of articles that may help you identify the issue. I’ve seen it before, but can’t remember where! Orchid Culture Articles - Sue Bottom

[Agnes]

Hello,
thank you very much for the links. I read them and still don't know what the cause of the yellowing of the leaves. Can it be a magnesium deficiency?

[isurus79]

Originally Posted by Agnes

Hello,
thank you very much for the links. I read them and still don't know what the cause of the yellowing of the leaves. Can it be a magnesium deficiency?

That seems unlikely since you're adding cal-mag to your fertilizer

[Paphman910]

I had the same thing happened to my Cattleya walkeriana as the conditions changed. The temperature was not as warm as before and the light level was decreased as I did a setup change.

It might be lack of light and temperature that my leaves started to turn yellow and became blotchy. Now it is almost leaveless but has a ton of new growth under warmer temperature and strong LED lights.

[Agnes]

Thank you very much for all your answers and help. I hope my walkerianas survive and soon have new growths. Spring is coming so I'm looking forward to putting all my orchids outside to let them have 'well-earned' holiday.