How and When to Deadhead Geraniums

Deadheading is the single most effective way to keep geraniums — both hardy cranesbills and tender pelargoniums — blooming continuously through summer. Left unchecked, spent flowers quickly set seed, signalling the plant to reduce flowering and redirect energy into seed production instead of new blooms.

Why deadheading matters

Geraniums are programmed to reproduce. Once a flower fades and begins forming a seed pod, the plant shifts resources away from producing new buds. By removing spent blooms before seeds set, you interrupt this cycle and encourage the plant to keep flowering. For pelargoniums grown as bedding or patio plants, this can extend the flowering season from early summer all the way to the first frosts.

How to deadhead pelargoniums correctly

The key with pelargoniums is to remove the entire flower stem, not just the individual petals. The stem carries the developing seed head. Trace each finished flower stalk back to where it meets the main stem or a leaf joint, then snap or cut it cleanly at this junction. Leaving a stub behind looks untidy and can introduce rot. The whole process takes only a minute or two per plant and is best done with your fingers — no tools needed.

• Check plants every two to three days during peak flowering.
• Remove entire flower stalks, not just faded petals.
• Snap cleanly at the base to avoid leaving stubs.
• Dispose of removed material rather than leaving it on the soil surface.

Deadheading hardy geraniums

Hardy cranesbills are managed slightly differently. Many varieties produce a single main flush of flowers in late spring or early summer. Rather than deadheading individual stems, the most effective technique is the "Chelsea chop" — cutting the whole plant back by about half once flowering declines. This removes all the spent material in one go and usually triggers a second flush of blooms within four to six weeks. Varieties like Geranium 'Rozanne' are longer-flowering and benefit from more regular deadheading throughout summer.

When to stop deadheading

As autumn approaches, you can let some flowers go to seed if you want natural self-seeding in the garden — hardy geraniums in particular spread pleasingly this way. For pelargoniums being overwintered, reduce deadheading in mid-autumn as you prepare to bring the plants inside. Once indoors in a cool, bright spot, pelargoniums rest and flower very little, so deadheading becomes less relevant until growth resumes in spring.

Common mistakes

The most common error is pinching off just the petals and leaving the developing seed pod. This looks tidy briefly but does nothing to stop seed set — the seed pod continues to mature. Always trace the stem back to its base. Another mistake is using blunt secateurs that crush rather than cut, potentially introducing disease. If you use tools, keep them clean and sharp.