When to plant
Plant gladiolus corms in spring, after the last frost. In warmer climates, you can stagger plantings every few weeks to extend the blooming period through summer.
Where to plant
Choose a spot with full sun—gladiolus require bright light to produce strong stalks and abundant blooms. The soil needs to be well-draining; soggy or compacted soil will hinder growth and increase rot risk.
Preparing the soil
Loosen the bed to about 20–25 cm deep. Remove rocks, roots, and compacted soil. Mix in compost or organic matter for fertility, and if your soil is heavy, add grit or coarse sand to improve drainage.
Planting the corms
Place each corm with the growing point (a bit like a small ridge or top) upward. Bury them at a depth of about 8 to 12 cm. Space them approximately 10 to 15 cm apart. Planting in groups rather than rows enhances visual impact.
After planting
Water gently to settle the soil, then keep the ground evenly moist (not soggy) as growth begins. Once foliage is established, water more deeply but less frequently, encouraging deep rooting.
During growth
Support tall varieties by staking early. As the flower spike emerges, fertilize lightly with a balanced feed. Deadhead spent blossoms to focus energy into corm restoration for next year.
After blooming
Allow foliage to yellow and die back naturally, which restores energy to the corms. In regions where winter frost is severe, lift the corms after foliage dies, dry them, and store in a cool, dry place until replanting. In frost-free areas, leave them in place with a protective mulch.
Extra tips
Plant in groups or drifts rather than single lines for greatest visual appeal. To prolong the season, plant in successive batches every few weeks. Use light mulch to moderate soil temperature. Avoid planting too deeply, especially in heavy soil, as this can weaken stems. If corms produce small offsets, keep the healthiest ones for replanting.
