The leaves do not get hot and the light is a led light that is pretty bright. The growth is not old. I have not been using magnesium but have oister shells in the media. For the media it is perlight orchiata and oister shells. I don't let is dry out and water when it is slightly moist. The water I use is tap and I think it is a bit hard. ThanksJust guesses, or ideas to look at:
It could either be high light maximum has been reached, senescence, or vitamin/mineral deficiency. Taking each separately:
Maximum Light: that is not enough yellowing to worry about. Roths do well in high sun and lower sun (moderate dappled shade). Since they are so tolerant of light intensity, I don't see that as much problem. Is yours in full sun, touching a window or light, or any of the other standard tests?
Related to light is heat: are the leaves hot to the touch? You may want a fan on them. Paphs/phrags like cool environments.
Senescence: which leaf is it and where is that hand of leaves in the growing cycle? An edge like that would make me think of senescence (gradual aging and death of an older leaf.) Usually if you have a new growth about half way grown, then one of the older leaves shuts down and starts to sacrifice its sugar storage to the younger growths. In this way the leaf is just like a pseudobulb.
Deficiency: what are you feeding them and how's your water? Have you been using calcium/magnesium? Magnesium has a lot to do with retaining green leaves.
Lastly: water-- is the medium allowed to dry out? With paphs and Phrags you want them to be moist at all times. No drying out. Roths like very pure water. How's your water?
Finally, check the roots. It will set the plant back for a year, but do you think that your roots are dying? That might explain "leathery" leaves.
Enter your email address to join:
Register today and take advantage of membership benefits.
Enter your email address to join: