Check species and season
Deciduous autumn leaf fall is normal. Evergreen or tropical leaf loss outside a transition needs investigation.
Leaf loss may be seasonal, or a response to relocation, weak light, cold, drought, waterlogging or pests. Pattern and timing matter more than the symptom alone.

A weakened tree usually needs stable light, correct moisture and time—not simultaneous pruning, feeding and repotting.
Deciduous autumn leaf fall is normal. Evergreen or tropical leaf loss outside a transition needs investigation.
Feel below the surface. A dry core and a saturated, cold root ball can both produce wilting and leaf loss.
Provide stable appropriate light and temperature. Avoid emergency fertilising, defoliation or major root work.