New leaf growth problem

[kwarren]

Some, but not all of my catts, create new growths whose leaves do not expand and open up and their pseudo bulbs do not thicken. The new unfurled leaf looks like a knife blade. Yet other catts do not have this problem. Does anyone know what is going on that would please help me understand?

[estación seca]

This can happen when humidity is way too low, or when you don't water enough.

[kwarren]

Thanks for your advice. That makes two of you who have given the same advice. In the beginning years I watered too much as many of us did. Now I think I'm under watering. But I repotted or threw away several catts yesterday and their oldest roots were all rotten. I suppose they were from the over-watering in recent past two years. But the few newest roots were okay, so I sprayed them with fungicide and repotted into smaller pots. It will take a couple of years to reach flowering again but at least I saved them. Thanks again for your advice!

[estación seca]

Cattleyas make roots only on the newest growths. Older pseudobulb's roots mostly serve to anchor the plant. A lot of people divide leaving about 4 growths total. The back bulb division often makes new growth if treated well. It's fine to cut off slimy dead roots, but often dried brown roots still have some functionality.

[kwarren]

My initial question was about the newest vegetative growths not unfurling and remaining in the shape of a knife blade. But thank you for reminding me that new roots only grow from the newest growths. That makes me feel better.