Phalaenopsis Leaf Loss in Heat: Root Rot or Stress?

Phalaenopsis Losing Lower Leaves in Orlando Heat

Angelo in Orlando: couple Phalaenopsis losing leaves—green mostly, but yellow at stem/trunk, continuing to tip. Leaves fall due to weight on rotting part. Wonder if natural leaf drop or problem. Treated one with fungicide, no change. Waters weekly, mists if hot (upper 90s), feeds 20-20-20 weekly.

Expert Response

Angelo, occasional older leaf yellow/fall is normal, replaced by new leaf. But high temps/humidity may degrade mix causing root rot. Check by unpotting one losing leaves—look for mushy/stringy roots. Repot to fir bark mix. Plants above 90°F prolonged may show heat stress—increase shading/air movement. Misting cools but plants must dry by nightfall; without good air movement, high humidity retards evaporation. Assume moved out of garage to shady spot.