Houseplants lose leaves for several different reasons, and identifying the cause correctly determines the appropriate response.
Overwatering and Root Rot
Overwatering is the most common cause of serious leaf loss in houseplants. When roots sit in saturated compost for extended periods, they are deprived of oxygen and begin to rot. Rotting roots cannot supply water and nutrients to the plant even though the compost is wet. The plant responds by shedding leaves to reduce its water demand. The leaves typically yellow before dropping, and the yellowing often starts on lower, older leaves and works upward as root function declines.
If leaf loss is accompanied by yellowing, a plant that feels lighter than expected when lifted (because rotting roots have decomposed), or a musty smell from the compost, root rot is likely. Remove the plant from its pot, inspect the roots, cut away any brown and mushy sections, and repot into fresh houseplant potting mix for optimal success.
Draughts and Temperature Changes
Many houseplants are sensitive to sudden changes in environment and respond to them by dropping leaves. Ficus species are notorious for dropping large numbers of leaves when moved to a new position, even if the new position is better lit and warmer than the previous one. The shock of changed conditions triggers leaf drop regardless of whether the new position is objectively better. Most plants re-establish and stop dropping leaves within a few weeks once they adjust to the new position.
Cold draughts from open windows, doors, or poorly sealed frames can trigger leaf drop on cold-sensitive tropical plants. Warm draughts from radiators or heating vents are equally problematic, causing rapid desiccation of leaves. Positioning plants away from both cold and warm air currents reduces draught-triggered leaf drop. See our guide on draughts and radiators for placement guidance.
Low Light and Seasonal Leaf Drop
Some leaf loss is normal when light levels drop in autumn and winter. Plants that were actively growing through summer may shed some older leaves as the plant adjusts to reduced light and slows its growth. This is particularly common in plants like Ficus, Scheffleras, and some Peperomias. As long as the loss is modest, the leaves being shed are older lower leaves, and new growth is still visible at the tips, this represents normal adjustment rather than a problem requiring intervention.
If a plant is dropping leaves more extensively in winter and showing signs of stretching (long, weak new growth), insufficient light is the more likely cause. Moving the plant to a brighter position or supplementing with a grow light addresses the root cause.
Underwatering
Underwatering causes leaf drop differently than overwatering: leaves typically wilt, crisp at the edges, and drop while still partially green or with dry brown colouration rather than the yellowing associated with overwatering. The compost will be very dry and pulling away from the pot walls. Check the compost moisture before assuming overwatering is the cause by pushing a finger several centimetres into the compost tells you whether it is dry or wet.
Natural Leaf Shedding
All plants shed old leaves as new growth replaces them. Loss of the oldest lower leaves on a plant that is otherwise growing well, with firm new leaves at the growing tips, is entirely normal. Yellowing and drop of the lowest, most shaded leaves on climbing or trailing plants is typical as the plant directs energy to newer growth. This requires no intervention other than removing the dropped leaves to keep the plant tidy.