Gladiolus: How to Plant, Grow, and Care for Sword Lilies

Gladiolus is a perennial favored for its beautiful, showy flowers. Blooms grow on tall spikes, making them stars of cutting gardens and back borders. Gladioli come in many colors and reach 2–6 feet tall. Excellent for cut flowers.

Planting Gladiolus

• Plant corms in spring after frost danger passes and soil has warmed.
• Loosen soil to 12–15 inches deep with a fork or tiller, then mix in a 2- to 4-inch compost layer.
• Set corms 4 inches deep, pointed end up. Cover firmly and water thoroughly.
• Space corms 3–6 inches apart.
• Gladioli prefer well-drained, light soil and full sun.
• Stake tall varieties at planting time, taking care not to damage corms with stakes.
• From planting to bloom and energy storage for next season takes ~90 days.

Care Through the Season

• Apply 2–4 inches of mulch to conserve moisture and suppress weeds.
• Water regularly if rainfall is under 1 inch per week; otherwise, water moderately to keep soil moist during growth.
• Remove faded flowers for continuous bloom. Once all flowers on a stalk finish, cut off the stalk.
• Leave foliage intact to mature and rejuvenate corms for next year.
• In zones 7–8, apply a hay or straw layer for winter protection.
• In zone 7 and colder, dig corms before first frost (see storage below).

Pests and Diseases

• Gladiolus corm rot (Fusarium wilt)
• Gray mold
• Viruses
• Aster yellows
• Spider mites
• Thrips
• Aphids

Harvest and Storage

Before first frost, dig up glads for winter storage.

• Use a spade to lift the entire plant, grasping the top to pull gently. Avoid bruising corms. Shake off soil, discard damaged corms. Cut stalk within 1 inch above corm. Save small cormels separately if desired.
• Dry corms in sun for 1–2 days if weather permits. Sift excess soil, place in wooden flats/trays. Cure in warm, airy location for 2 weeks (80–85°F). Remove and discard oldest bottom corms (from base of new one).
• Dust clean corms with fungicide ("bulb dust") to prevent disease. Place dust and corms in a paper sack and shake vigorously.
• Store large new corms in paper boxes, open paper bags, cloth bags, wooden trays with screen bottoms, or old onion sacks. Stack/hang for air circulation. Store at 35–45°F in low humidity. A cool basement works well. Do not allow corms to freeze.
• Replant in spring for another year of blooms.
• Learn more winter storage tips for gladiolus.

Recommended Varieties

• Candyman — beautiful deep pink flowers.
• Dream's End — good back border plant with 3-foot flower spikes and light orange flowers with large yellow centers.
• Prins Claus — white flowers with pink splashes on petals.

Wit & Wisdom

Gladiolus is one of the August birth flowers.