Jean-Pol GRANDMONT / CC BY-SA 3.0
Gladiolus
Gladiolus
Overview
Dramatic sword-like flower spikes that open from bottom to top in nearly every color of the rainbow, gladiolus are named from the Latin word for sword. These summer-blooming corms produce some of the tallest and most showy cut flowers available to home gardeners. In parts of Africa, gladiolus corms are a traditional food source, roasted or ground into flour.
Growing Conditions
How to Grow Gladiolus
Gladiolus (Gladiolus) is a forb/herb that grows to about 3 feet tall and 2.5 feet wide.
To grow gladiolus, give it full sun. It is hardy across USDA hardiness zones 8–12. Plant it in rich, well-drained, sandy loam, at a slightly acidic pH of 6–7. It does best with even, moderate watering.
Exact sowing, transplanting, and harvest months shift by climate zone — the planting calendar below lays them out for cool through hot regions. Its flowers appear from May through June, offering high value to pollinators. It feeds two tables at once: yours and the pollinators’.
Companion Planting & Soil
Gladiolus grows well alongside marigold, dahlia, and zinnia.
Good Companions
Planting Calendar
When to sow, transplant, and harvest by growing zone.
| Zone | Action | Months | Notes |
|---|---|---|---|
| Cold (1-2) | Transplant | May — Jun | Plant corms 4-6" deep after last frost; succession plant every 2 weeks for continuous bloom |
| Cold (1-2) | Bloom | Jul — Sep | Harvest when lowest 2-3 florets open; dig corms before frost and store dry |
| Cool (3-4) | Transplant | Apr — Jun | Plant corms in spring; stagger plantings every 2 weeks |
| Cool (3-4) | Bloom | Jul — Sep | Summer bloom; dig corms in fall; cure 2 weeks; store at 35-45°F |
| Moderate (5-7) | Transplant | Mar — May | Plant in spring; stake tall stems; excellent cut flower |
| Moderate (5-7) | Bloom | Jun — Sep | Long bloom season from staggered plantings |
| Warm (8-9) | Transplant | Feb — Apr | Plant in late winter/spring; corms perennialize in zones 8+ |
| Warm (8-9) | Bloom | Apr — Jul | Spring/summer bloom; leave corms in ground year-round |
| Hot (10+) | Transplant | Jan — Mar | Plant in winter/spring; perennial in zones 8-11 |
| Hot (10+) | Bloom | Mar — Jun | Spring bloom; perennial in hot zones |
Uses
In the Kitchen
In the kitchen: corms roasted or boiled as a starchy food in Africa.
Beyond the Garden
Gladiolus earns its keep past the plate, too: premier tall cut flower for dramatic bouquets; succession planting provides months of cut flowers; exhibition and competition flower culture.
