Do I need to dig up my bulbs in winter?

In climates where the ground freezes, you must dig up and store the corms in a cool, dry place.

How deep should I plant them?

Plant the corms 10 to 15 centimeters deep.

Plant guide

Sword Lily.

Gladiolus

Pronounced glad-ee-OH-lus

Also known as Gladioli, Painted Ladies, Sword Lilies, gladiolus, gladioluses

Gladiolus × hortulanus — Photo by Jhonatan Matheus (CC BY) via iNaturalist

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.

Another photo of Sword Lily — Photo by Laura Clark (CC BY) via iNaturalist

At a glance

Care level: Easy
Plant type: Perennial corm
Light: Full sun
Indoor light: Direct sun
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 per corm.
Fragrance: Light
Deer and rabbits: Moderate

Signs it needs repotting

Roots growing out of the drainage holes.
Stunted growth despite regular feeding.
Corms becoming too crowded in the pot.

Safety

People: All parts of the plant are considered toxic if ingested and may cause skin irritation upon contact.
Pets: Gladiolus is toxic to cats and dogs if ingested.
Children: The corms look like small onions and pose a significant ingestion risk to small children.
Contact allergens: Handling the corms or foliage can cause contact dermatitis in sensitive individuals.
Airborne allergens: The pollen can be an irritant for those with severe seasonal allergies.
Edibility: Gladiolus corms are toxic and should not be consumed by humans or pets.

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: red, pink, yellow, white, purple, orange, 5 to 15cm

Problems to watch for

Fusarium WiltCommon
ThripsCommon
AphidsUncommon
Botrytis BlightUncommon
Bulb RotUncommon
Root RotUncommon

By symptom

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Growing it

Propagation: division, seed
When to plant: spring
Overwintering: In cold regions, dig up corms after the first frost, clean them, and store in a mesh bag in a cool, dark, frost-free location.
In containers: They grow well in containers at least 30 centimeters deep, provided there is excellent drainage.

Cormel Division

Dig up the corms in autumn after the foliage yellows.
Gently separate the small cormels from the main mother corm.
Store the cormels in a cool, dry place until spring planting.

Plant them in groups of seven or more to create a strong visual impact and support pollinator visits.

Grows well with

Zinnia — They share similar sun and water requirements while providing a nice color contrast.
Lavender — The fine texture of lavender complements the bold, upright spikes of the gladiolus.

Similar species

Crocosmia — They share a similar growth habit and are also members of the iris family.
Freesia — They are related cormous plants that bloom in similar conditions.

Science

Family: Iridaceae
Genus: Gladiolus
Order: Asparagales
Class: Liliopsida
Native range: Africa and the Mediterranean
Conservation: Not of conservation concern.

They grow in well drained soils and rely on specialized pollinators to reach their deep nectar tubes.

Value to wildlife: nectar source
Pollinators: bees, butterflies, hummingbirds
Uses: cut flowers, border gardens, container gardening

Through the year

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Flowering

Fruiting

Foliage

Ecological indicators

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

Taxonomy resolved against GBIF.

Questions people ask

Do I need to dig up my bulbs in winter?: In climates where the ground freezes, you must dig up and store the corms in a cool, dry place.
How deep should I plant them?: Plant the corms 10 to 15 centimeters deep.

Where the name comes from

The name comes from the Latin gladius, meaning sword, referring to the leaf shape.

Good to know

Gladiolus were once used in ancient times as a poultice to draw out thorns.
They are a popular choice for floral arrangements due to their long vase life.
The plants are native to Africa and the Mediterranean region.
They are often called sword lilies.

Also in

Plants toxic to cats and dogs

Keep your sword lily growing

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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.