Crocosmia × crocosmiiflora 'Vesuvius' (Montbretia) — Clump-forming, upright with arching flower sprays

Overview

Crocosmia × crocosmiiflora 'Vesuvius' is a clump-forming, upright with arching flower sprays perennial in the genus Crocosmia, part of the Iridaceae family, with deciduous; stiff, pleated, sword-shaped, mid to bright green foliage. Crocosmia × crocosmiiflora 'Vesuvius' grows best in full sun to partial shade, and tolerates fertile and moisture-retentive loam improved with organic matter soils and acid and neutral or alkaline pH. Its UK hardiness is rated H4-H6. Suggested uses include borders, cut flowers, cottage gardens and pollinator gardens.

About

Crocosmia × crocosmiiflora 'Vesuvius' is a clump-forming perennial in the iris family with upright growth and arching flower sprays. It carries stiff, pleated, sword-shaped mid to bright green leaves that are deciduous. Flowering runs from July to September. It suits full sun to partial shade on fertile, moisture-retentive loam in a sheltered, south-, west- or east-facing position.

About the genus

Crocosmia, also known as montbretia, is a small genus of flowering plants in the iris family, Iridaceae. It is native to the grasslands of southern and eastern Africa, ranging from South Africa to Sudan. One species is endemic to Madagascar.

Wikipedia contributors, "Crocosmia", CC BY-SA 4.0 — Crocosmia

In the garden

Crocosmia × crocosmiiflora 'Vesuvius' is a clump-forming perennial (Iridaceae) noted for its upright habit topped by arching sprays of flowers and stiff, pleated, sword-shaped leaves. Flowering occurs from July to September, providing late-summer vertical interest in the border. Grow it in full sun to partial shade on fertile, moisture-retentive loam improved with organic matter; the plant tolerates acid, neutral or alkaline soil so long as it remains moist but well drained. Choose a sheltered site with a south-, west- or east-facing aspect to protect the shoots from prevailing winds and winter exposure. The hardiness range H4–H6 (average to very hardy) means it will survive typical UK winters where soils do not remain waterlogged and plants are not left exposed to driving wind. Use Crocosmia × crocosmiiflora 'Vesuvius' in mixed borders, cottage-style plantings, pollinator areas or for cutting. Plant in groups to form a vertical accent behind lower perennials, or place nearer the front where its arching sprays can be appreciated at close range. The long, arching flower stems make it suitable for summer vase work and garden-to-table arrangements.

Growing conditions

Best soil and position for Crocosmia

Sunlight: Full sun to partial shade
Soil type: Fertile, moisture-retentive loam improved with organic matter
Soil pH: Acid, neutral or alkaline
Soil moisture: Moist but well drained
Aspect: South, west or east facing
Exposure: Sheltered
UK hardiness: H4-H6

Plant details

Crocosmia × crocosmiiflora 'Vesuvius' size, habit and characteristics

Plant type: Perennial
Habit: Clump-forming, upright with arching flower sprays
Foliage: Deciduous; stiff, pleated, sword-shaped, mid to bright green
Suggested uses: Borders, cut flowers, cottage gardens, pollinator gardens

Care notes

Pruning and caring for Crocosmia × crocosmiiflora 'Vesuvius'

Cultivation: Plant corms in spring rather than autumn, setting them around 10cm deep in ground that holds summer moisture, since drought during bud formation is what produces a poor showing. Clumps become congested within a few years and flowering falls away, so lift and divide regularly. The most vigorous kinds spread strongly and are best kept away from delicate neighbours; in colder gardens a dry winter mulch protects the corms.
Pruning: Remove faded flower stems, or leave the seed capsules for autumn interest. Cut the foliage down once it has yellowed in late autumn, or leave it as crown protection and clear in early spring.
Propagation: Divide congested clumps in spring, separating the chains of corms and replanting the plump upper ones. Species can be raised from seed.
Pest resistance: Little troubled outdoors; red spider mite occurs on plants under glass, and slugs graze new shoots.
Disease resistance: Robust in suitable conditions. Gladiolus rust and corm rot occur occasionally, the latter where drainage is poor.

Frequently asked questions

How do I grow Crocosmia × crocosmiiflora 'Vesuvius'?

Plant corms in spring rather than autumn, setting them around 10cm deep in ground that holds summer moisture, since drought during bud formation is what produces a poor showing. Clumps become congested within a few years and flowering falls away, so lift and divide regularly. The most vigorous kinds spread strongly and are best kept away from delicate neighbours; in colder gardens a dry winter mulch protects the corms.

Where is the best place to plant Crocosmia × crocosmiiflora 'Vesuvius'?

Crocosmia × crocosmiiflora 'Vesuvius' prefers full sun to partial shade. It suits sheltered positions.

What soil does Crocosmia × crocosmiiflora 'Vesuvius' need?

Crocosmia × crocosmiiflora 'Vesuvius' grows best in fertile and moisture-retentive loam improved with organic matter soil. It prefers acid and neutral or alkaline soil. Aim for soil that stays moist but well drained.

How do I prune Crocosmia × crocosmiiflora 'Vesuvius'?

Remove faded flower stems, or leave the seed capsules for autumn interest. Cut the foliage down once it has yellowed in late autumn, or leave it as crown protection and clear in early spring.

Is Crocosmia × crocosmiiflora 'Vesuvius' hardy in the UK?

Crocosmia × crocosmiiflora 'Vesuvius' has an RHS hardiness rating of H4, meaning it is hardy through an average UK winter, tolerating -10 to -5°C.

How do I propagate Crocosmia × crocosmiiflora 'Vesuvius'?

Divide congested clumps in spring, separating the chains of corms and replanting the plump upper ones. Species can be raised from seed.

More in the Crocosmia genus

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