Why Are My Geranium Leaves Dropping Off?

Leaf drop in geraniums can feel sudden and alarming, but most of the time it is the plant's response to a specific stress that you can identify and correct. A few lower leaves falling as the plant ages is entirely normal, but when healthy upper leaves begin dropping, or when a large number fall at once, something has changed in the plant's environment or health. Here is how to diagnose what went wrong.

Temperature Shock and Cold Draughts

Pelargoniums drop leaves rapidly after exposure to cold temperatures, cold draughts, or sudden temperature swings — particularly when moved from a warm greenhouse or windowsill directly into a cold outdoors environment. This is called cold shock. The leaves may yellow first or may simply drop without much warning. The remedy is to acclimatise the plant gradually over seven to ten days, starting with a few hours of outdoor air each day and increasing exposure. Keep plants away from cold windows at night and away from air conditioning vents indoors.

Overwatering and Root Rot

Saturated compost leads to root rot, and one early symptom before the plant collapses completely is leaf drop — the root system can no longer support the full leaf canopy, so the plant sheds leaves to reduce water loss. Check for soggy compost, a musty smell, or dark stem bases. If you catch it early, allow the compost to dry thoroughly and improve drainage. If root rot is established, repot into fresh gritty compost after trimming away dead roots. Water much more sparingly going forward.

Inconsistent Watering

Fluctuating between bone-dry and soaking wet triggers leaf drop in pelargoniums. The plant struggles to manage its water budget when the root environment is unpredictable. Aim for consistent moisture — let the top inch dry out, then water thoroughly and drain completely. Regular, rhythmic watering prevents the stress cycles that cause leaves to drop. Using a well-draining compost mix with added perlite makes it easier to maintain this consistency.

Moving the Plant to a New Location

Geraniums often shed leaves simply because they have been moved from one environment to another — different light levels, humidity, and temperature all signal the plant to adjust. This is particularly common with newly purchased plants that have been grown in commercial glasshouse conditions and then placed in a home environment. Leaf drop from relocation stress usually settles within two to three weeks as the plant adjusts. Avoid further moves during this period and maintain consistent care.

Natural Lower-Leaf Shedding

Both pelargoniums and hardy geraniums shed their lowest, oldest leaves as a normal part of growth. These leaves yellow, then drop cleanly. If the upper leaves look healthy and the plant is growing and flowering, this is not a problem. Remove fallen leaves promptly to prevent them harbouring disease at the soil surface. Tidy bare lower stems by cutting them back to a side shoot or node to keep the plant looking neat and compact.