I’ve got brown and/or purple leaves on many of my cattleyas. Namely, my Maikai Louise, my Nodoso (Lady of the Night), and several others. Not with my Dendrobiums, just my Catts. For reference purposes, They’re under the screened lanai which faces SE (so they get morning sun and sun up until about 2:00PM, although some of that is sometimes shadier because of some Palm trees and the fronds that are located outside the lanai). I water them about once a week. They all have Dynamite in the red can which I applied in early March. Additionally, about once a month I fertilize with an Orchid Fertilizer/Epsom Salt/Fish Oil combo of 3 Tbsp (1 of each) /gallon of water. The Nodoso, especially, are a concern. Leaves turn brown,  dry up and just fall off. They all APPEAR to be healthy, other than that.

So…too much sun? Too little sun? Too much fertilizer? Any ideas/sugestions? (Yes, I will bring them to the next Growers Meeting.)