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Gladiolus 'Black Surprise'

sword lily 'Black Surprise'

A cormous perennial, 90cm high, with green sword-shaped leaves and dramatic deep purple flowers, held on spikes of up to 10 velvety blooms. This glamourous corm flowers from late summer and into autumn

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Ultimate height

0.5–1 metres

Time to ultimate height

2–5 years

Ultimate spread

0.1–0.5 metres

Chalk

Loam

Sand

Moisture

Moist but well–drained, Well–drained

pH

Acid, Alkaline, Neutral

	Stem	Flower	Foliage	Fruit
Spring
Summer
Autumn
Winter

Full sun

Aspect

East–facing or South–facing or West–facing

Exposure

Sheltered

Hardiness
Hardiness ratings
All ratings refer to the UK growing conditions unless otherwise stated. Minimum temperature ranges (in degrees C) are shown in brackets
H1a: under glass all year (>15C)
H1b: can be grown outside in the summer (10 - 15)
H1c: can be grown outside in the summer (5 - 10)
H2: tolerant of low temperatures, but not surviving being frozen (1 to 5)
H3: hardy in coastal and relatively mild parts of the UK (-5 to 1)
H4: hardy through most of the UK (-10 to -5)
H5: hardy in most places throughout the UK even in severe winters (-15 to -10)
H6: hardy in all of UK and northern Europe (-20 to -15)
H7: hardy in the severest European continental climates (< -20)

Botanical details

Family: Iridaceae
Native to GB / Ireland: No
Foliage: Deciduous
Habit: Columnar upright
Potentially harmful: Ornamental bulbs, not to be eaten. Wear gloves and other protective equipment when handling. Pets: Harmful if eaten. For further information and contact numbers regarding pets, see the HTA guide to potentially harmful plants
Genus: Gladiolus are cormous perennials with fans of sword-shaped or linear leaves and spikes of funnel-shaped flowers
Name status: Unresolved

How to grow

Cultivation

Grow in fertile, well-drained soil in full sun, planting the corms 15cm deep in spring, on a bed of sharp sand to aid drainage; in frost-prone areas, lift when the leaves turn yellow-brown, and store the new corms in a dry, frost-free place until the following spring; in milder areas, add a thick dry mulch over winter

Propagation

Propagate by division, separating cormlets when dormant

Suggested planting locations and garden types

City and courtyard gardens
Cottage and informal garden
Flower borders and beds
Wall side borders
Cut flowers

Pruning

No pruning required

Pests

May be susceptible to gladiolus thrip, aphids and slugs

Diseases

May be susceptible to gladiolus corm rot, grey moulds (Botrytis), Fusarium bulb rot, gladiolus core rot, gladiolus dry rot, gladiolus scab and neck rot, fungal leaf spot, and virus diseases

Get involved

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