Gladiolus
Gladiolus x hortulanus
Gladioli produce tall, sword-like spikes of funnel-shaped flowers from July to September, making them a favourite for cut flower growers. Each stem carries 12-20 blooms that open sequentially from the bottom upwards. Available in almost every colour, they bring vertical drama to borders and are staples of flower arranging. Grown from corms, they are half-hardy and must be lifted in autumn in most UK regions.
Full growing guide
How to Grow Gladioli in the UK
How to grow gladiolus
Plant corms 10-12 cm deep and 10-15 cm apart from late March to May. Stagger plantings every two weeks for a succession of blooms through summer. Choose a sheltered, sunny spot with fertile, well-drained soil. Stake tall varieties before flowers open to prevent wind damage. Water regularly during the growing season, especially in dry weather. Feed fortnightly with a balanced liquid fertiliser once flower spikes appear. For cut flowers, harvest when the bottom two or three florets have opened. After the first frost, cut stems to 5 cm above ground level. Lift corms carefully, remove soil, and dry in a warm, airy place for two to three weeks. Store in paper bags in a cool, frost-free location over winter. Replant the following spring.
Pruning
No pruning required. Remove individual spent florets to keep the spike looking tidy. Cut flower spikes for vases when the lowest florets begin to open.
Propagation
- Cormlets (detach from parent corm at lifting time)
- Seed (slow, takes 2-3 years to flower)
Common problems
- Gladiolus thrips
- Grey mould (Botrytis)
- Fusarium corm rot
- Wind damage to tall stems
Good companions
Related guides
UK Flower Planting Calendar
What flowers to sow and plant each month in the UK, from sweet peas in winter to tulips in November, with easy tips on frost, bulbs and biennials.
Cottage Garden Planting Plan for the UK
How to plan a cottage garden border: the classic plants, how to layer them, colour ideas and a ready-made planting plan for a sunny UK border.