Lycaste leaves rotting
 

I have two Lycastes, both with leaves rotting at the base. The rot is worse on the innermost/newest leaves. I had them in a spot where they might get dripped on, so wondering if water falling onto the leaves might have done this. In any case I’m hoping for some advice on what to do to help them out.

It really does look like they have picked up a bacterial or fungal infection from being dripped upon and then not having an opportunity to dry. I would be inclined to dust the area with cinnamon, which does have antifungal effect, as well as facilitating drying. I know that some forum members treat with peroxide. Probably would do no harm. But first, move them to where they don't get dripped on... water alone would not tend to do that, but if they were under a planter or some such thing where the water was passing through dirt first, would be easy to pick up organisms. Fortunately, Lycastes are deciduous, so if if these leaves are lost, the plant should be fine next year, as long as the "crud" does not get into the pseudobulb.

Thank you for your help, I'll hit them with some cinnamon. The water was dripping from some tillandsias, so plants, but no dirt. These are growing outside, so exposed to whatever is blowing around...

I grow all Lycastes (along with nearly everything else) outside, and haven't see this particular issue... overhead watering has never been a problem, but I can see where not drying out, plus picking up whatever was clinging to those tillies , might be the culprit. Many Tillandsias have tubular growth or some other way of holding water - giving them a good chance to breed organisms. (I have has Bromeliads get rather stinky when full of water for awhile - doesn't seem to hurt them, but would not want to get that stagnant water on anything else)

Follow-up question: The rot (soft/brown/thinning/wet) areas on these leaves are spreading, but very slowly. I used some cinnamon, and a fungicide on the plant. My question is: should I remove the leaves? That would mean removing the only growths on the plant (I.e., cutting them both back to only bulbs), as every leaf is now brown near the base

In my experience nothing helps and they will die back. I had the same thing happen to 2 growths and they died. However 3 new growths were initiated so there was good news. That said you just never know with orchids so try it.

The leaves will probably die back... but as long as they are green, they are supplying energy to the plant. If the rot looks like it i is heading downward for the pseudobulb, cut the leaf if it is just spreading upward, you could leave it and let the plant do its thing. As long as the pseudobulb is healthy the plant will be fine. If you see new growth, then totally don't worry about the old.

Got it, thank you again

Did you let them dry out too long? A lot of deciduous orchids will drop their leaves suddenly if not watered enough during the growing season. Also did you have plenty of hot weather earlier this summer?

I’ve kept them pretty wet since they began growth. I grow outdoors in coastal San Diego. It’s been warmer than usual lately, but wasn’t especially hot in the early summer. The rot spread, so I’ve now cut them back to the bulbs. I’m not sure what to hope for now...