How to grow Gladiolus (Large-Flowered Mixed)

Gladiolus × hortulanus

🌸 Flower 🔁 Perennial

Tall, stately spikes of ruffled flowers in late summer — plant a batch every two weeks for a long run of cut flowers.

At a glance: Sow mid April to mid June.

When to sow, plant and harvest

JanFebMarAprMayJunJulAugSepOctNovDec

Sow outdoors

Flowers

Timed for a typical UK garden (last frost mid-April). The app uses your own town's frost dates.

Mid April – mid June · around the last spring frost
Plant Outdoors
Plant 10–15 cm deep, 15 cm apart, in rich soil in full sun once frosts are over.
14–28 days after “Plant Outdoors” · Late April – mid May
Look for Shoots
Shoots should be up. Protect them from slugs — they love young dahlia and gladiolus shoots.
7–21 days after “Look for Shoots” · Early May – mid May
Stake the Stems
Put in a stout cane or stake and tie stems in as they grow — the flowers are heavy.
50–90 days after “Stake the Stems” · Late June – early August
First Flowers — Deadhead Regularly
Cut faded flowers (and flowers for vases) to keep new buds coming. Take a photo for your journal!

April
Start Them Off Again
Check stored tubers/corms, discard any soft ones and pot them up (or plant out once frosts are over).
October
Lift and Store
After the first frost blackens the leaves, cut stems to 10 cm, lift, dry off upside down, and store in dry compost somewhere frost-free.