Purple Leaf Backs on Orchids: Good Light Indicator

Angelo moved orchids to a pool-area shade structure (PVC + 75% shade cloth, east-facing, morning sun through screen). After 3 weeks, some leaf undersides turned purple. Asked if this was okay.

Purple Undersides = Good Light Exposure

Anthocyanin pigment on leaf undersides indicates the plant is receiving strong, beneficial light. This is desirable.

Watch for Purple on Top Surface

If purple appears on the upper (light-facing) leaf surface, it's a warning—approaching sunburn. Back off light slightly.

Setup Assessment

Structure sounds excellent: 75% shade, east morning light, breeze, humidity from pool. Cattleyas tolerate ~50% shade; Phalaenopsis prefer ~70%. If any burning, add rated shade cloth over sensitive plants.