Growing Geraniums in Containers

Pelargoniums are among the best plants you can grow in containers. They are naturally adapted to dry, free-draining conditions, they flower reliably all summer with minimal fuss, and they tolerate being slightly pot-bound — which actually encourages more flowering. With the right setup, container geraniums can be one of the most rewarding plants on a patio or doorstep.

Choosing the right pot

Drainage is the priority. Always choose a pot with at least one good drainage hole in the base. Terracotta pots are ideal as they are porous and allow the compost to dry out between waterings, reducing the risk of overwatering. Plastic pots are fine but retain moisture longer — adapt your watering frequency accordingly. A pot 20–30cm in diameter suits one to three pelargoniums well. Avoid going too large as excess compost stays wet too long.

Compost and potting

A free-draining compost is essential. Use a multipurpose compost mixed with around 20–30% perlite or coarse grit to improve drainage. Avoid heavy, water-retentive composts designed for moisture-loving plants. Place a layer of crocks or gravel in the base of the pot before filling to keep the drainage hole from becoming blocked. Firm the compost moderately — not too tightly — and leave a 2–3cm gap between the compost surface and the pot rim to allow for watering.

• Always use pots with drainage holes.
• Mix in 20–30% perlite for drainage.
• Slightly pot-bound plants flower more freely.
• Repot into a pot one size larger if growth slows.

Watering container geraniums

Allow the compost to dry out noticeably between waterings. Push your finger 2–3cm into the compost; if it still feels damp, wait another day. When you do water, water thoroughly until it drains freely from the base, then leave until the surface is dry again. This mimics the natural dry-then-wet cycle these plants evolved with. Consistent overwatering is the most common cause of root rot in container geraniums.

Feeding and maintenance

Container geraniums need regular feeding because frequent watering washes nutrients out of the compost. Apply a high-potassium liquid fertiliser every one to two weeks from late spring through to late summer. Deadhead spent flower stalks regularly to maintain continuous flowering. In autumn, reduce watering and stop feeding as growth slows. Bring frost-tender pelargoniums indoors before the first frosts to overwinter in a cool, frost-free place.