Why Is My Geranium Wilting?

A wilting geranium can be alarming, particularly when you have been watering regularly and the plant looked healthy only days ago. The frustrating truth is that both too much and too little water produce near-identical wilt symptoms, so checking the compost moisture is always your first step. Beyond watering mistakes, hidden root pests and fungal diseases can collapse a plant within days. Here is how to work through each possibility.

Underwatering

This is the simplest cause and the easiest to fix. If the compost is bone dry and pulling away from the pot sides, the plant has run out of water. Pelargoniums in terracotta pots or hanging baskets dry out remarkably fast on warm days — sometimes within 24 hours. Submerge the entire pot in a bucket of water for 20–30 minutes to rehydrate the root ball evenly, then drain fully. The plant usually perks up within a couple of hours. Going forward, check moisture daily in summer and water when the top inch of compost is dry.

Overwatering and Root Rot

If the compost is wet or smells musty and the stems feel soft or dark at the base, root rot is the likely cause. The rotted roots can no longer supply water to the leaves, so the plant wilts even though the soil is sodden. Tip the plant out and inspect the roots — healthy roots are white or cream; rotted roots are brown, slimy, and smell unpleasant. Cut away all affected roots with clean scissors, dust the cuts with powdered cinnamon or sulphur, and repot into fresh, gritty compost. Let the compost almost dry out between waterings from this point on.

Vine Weevil Root Damage

Vine weevil grubs are one of the most destructive hidden causes of wilt in container geraniums. The white, C-shaped larvae eat roots from below through late summer and autumn, and a plant can look perfectly healthy until most of the root system is gone. When it wilts and does not recover after watering, tip the pot and look for grubs in the compost. Remove every grub by hand and treat the remaining root system with a biological nematode control (Steinernema kraussei) watered in during late August or September. Replace the compost entirely.

Blackleg Disease

Blackleg is a bacterial or fungal stem rot where the stem base turns dark, soft, and slimy, then the plant wilts rapidly and usually cannot be saved once the blackening has spread. It often follows a period of cold, wet conditions or is introduced via unsterilised compost. Remove and bin the affected plant immediately; never compost it. Wash the pot thoroughly with dilute bleach solution before reusing. Use fresh, sterile compost for replacements and ensure excellent drainage from the start.

Heat and Sun Scorch Wilt

On very hot days, pelargoniums in direct sun may wilt as a temporary response to heat stress even when the compost is adequately moist. Move the pot to light shade and mist the foliage lightly; the plant normally recovers by evening. This type of wilt is not a crisis, but repeated exposure weakens plants. Positioning containers where they receive morning sun but are shaded from the hottest afternoon rays reduces the risk significantly.