Do I need to dig them up?

In colder climates, you must dig up the corms before the first frost.

How deep should I plant them?

Plant them 4 to 6 inches deep in well draining soil.

Plant guide

Gladiolus.

Gladiolus L.

Pronounced glad-ee-OH-lus

Gladiolus are striking perennials known for their tall, sword shaped leaves and impressive spikes of funnel shaped flowers. They grow from corms and add a dramatic vertical element to any garden bed. These plants are a favorite for cut flower arrangements because they last a long time in a vase.

At a glance

Care level: Easy
Plant type: Perennial corm
Light: Full sun
Indoor light: direct
Water: Every 5 to 7 days
Mature size: 150 cm
Growth rate: medium
Hardiness: USDA 7 to 10
Bloom time: Mid to late summer

Care

Plant corms in well draining soil once the danger of frost has passed. Watch for thrips or aphids on the foliage and ensure the soil does not stay soggy to prevent corm rot. Stake the taller varieties to keep them from leaning over in heavy winds.

Watering: Keep the soil consistently moist during the active growing season.
Feeding: Apply a balanced fertilizer once growth begins and again after blooming.
Pruning: Remove spent flower spikes to keep the plant tidy and cut back foliage after it yellows.
Repotting: Corms should be lifted and stored in cool areas during winter in colder climates.
Soil: Well draining, sandy loam
Soil pH: 6.0 to 7.0
Temperature: 5 to 30°C
Humidity: 40 to 60%
Drought tolerance: moderate
Lifespan: Perennial, typically 3 to 5 years with proper care.
Deer and rabbits: low

Signs it needs repotting

Corms are crowded and pushing against the pot walls.
Flowering performance has significantly declined.
Water drains too quickly due to excessive root mass.

Safety

People: All parts of the plant are considered toxic if ingested, and the sap can cause skin irritation in sensitive individuals.
Pets: Gladiolus is toxic to cats and dogs if ingested.
Children: Keep bulbs away from children as they look like onions but are toxic if eaten.
Contact allergens: The sap may cause contact dermatitis in some people.
Airborne allergens: Pollen can trigger allergic reactions in sensitive individuals during the blooming season.
Edibility: Gladiolus corms are toxic if ingested and should never be consumed.

How to identify it

Tall, sword shaped foliage
Spikes of funnel shaped flowers
Grows from underground corms
Flowers open from bottom to top

Height: 0.6 to 1.5m
Spread: 0.15 to 0.3m
Leaves: green, deciduous
Flowers: white, pink, red, yellow, purple, orange, 5 to 15cm

Common problems

Thrips — These tiny insects cause streaking and deformed flowers.
Fusarium wilt — A fungal infection that causes yellowing leaves and rotting corms.

Growing it

Propagation: cormels, seed
When to plant: spring
Overwintering: In cold regions, dig up corms after the first frost, clean off soil, and store in a cool, dry place over winter.
In containers: They grow well in deep pots, provided the container is at least 12 inches deep for proper root development.

Cormel separation

Carefully dig up the main corm after the foliage dies back.
Remove the small cormels found attached to the base of the parent corm.
Store cormels in a cool, dry place until spring planting.
Plant cormels in a nursery bed to grow to flowering size over 1 to 2 years.

Plant them behind shorter annuals to hide the foliage as it fades after blooming.

Grows well with

Zinnia — They share similar sun and water requirements.
Salvia — The vertical spikes of gladiolus contrast nicely with salvia blooms.

Keep away from

None notable — Gladiolus generally coexist well with most garden plants.

Similar species

Crocosmia — They share a similar growth habit and corm structure.

Science

Native range: Native to Africa, the Mediterranean, and parts of Asia.
Conservation: Most common garden varieties are not of conservation concern.

They thrive in open, sunny habitats where their corms can dry out during dormant periods.

Value to wildlife: nectar source
Pollinators: bees, hummingbirds
Uses: cut flowers, border planting, pollinator gardens

Through the year

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Flowering

Fruiting

Foliage

Ecological indicators

Salinity: 2/9
Soil reaction: 6/9
Light: 8/9
Temperature: 7/9
Moisture: 5/9
Nutrients: 6/9

Questions people ask

Do I need to dig them up?: In colder climates, you must dig up the corms before the first frost.
How deep should I plant them?: Plant them 4 to 6 inches deep in well draining soil.

Where the name comes from

The genus name Gladiolus is Latin for little sword, describing the leaf shape. It is a member of the Iridaceae family.

Good to know

Gladiolus are the birth flower for August.
They are often called sword lilies.
They grow from corms, not true bulbs.

Is your gladiolus looking unwell?

This page is a general guide. Pocket Botanist diagnoses problems from a photo of your actual plant, works out watering for your light and conditions, and reminds you when care is due.

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This guide was generated with AI and checked against GBIF taxonomy. It is general information, not horticultural or veterinary advice. Read about how we build these guides.