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

Overview

Crocosmia × crocosmiiflora 'Sprowston Glory' 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 'Sprowston Glory' 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, naturalizing in moist and well-drained garden areas..

About

Crocosmia × crocosmiiflora 'Sprowston Glory' is a clump-forming perennial in the iris family that bears upright growth with arching sprays of flowers. The foliage is deciduous, stiff and pleated, forming sword-shaped fans of mid to bright green. It flowers July to September on arching spikes and prefers a sheltered, south-, east- or west-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 'Sprowston Glory' belongs to the Iridaceae and grows as a clump-forming, upright perennial with arching flower sprays and sword-shaped leaves. The deciduous fans of stiff, pleated foliage give the clump a clear, vertical presence through the growing season, and flowering runs from July to September. Plant it where it receives full sun to partial shade in a fertile, moisture-retentive loam improved with organic matter. It tolerates acid, neutral or alkaline soils but needs moist yet well-drained conditions, so avoid waterlogged sites. Choose a south-, west- or east-facing aspect in a sheltered spot to reduce wind damage to the arching spikes. The rating H4–H6 means it will survive UK winters from average (H4) to very hardy (H6) conditions, though sheltered situations will protect the stems and flowers. Use 'Sprowston Glory' in mixed borders, planted in groups for impact, or allow it to naturalise in moist but well-drained garden areas. It also produces practical cut stems; cut flowering spikes between July and September for indoor displays, when the lower florets are opening to extend vase life.

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 'Sprowston Glory' 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, naturalizing in moist, well-drained garden areas.

Care notes

Pruning and caring for Crocosmia × crocosmiiflora 'Sprowston Glory'

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 'Sprowston Glory'?

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 'Sprowston Glory'?

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

What soil does Crocosmia × crocosmiiflora 'Sprowston Glory' need?

Crocosmia × crocosmiiflora 'Sprowston Glory' 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 'Sprowston Glory'?

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 'Sprowston Glory' hardy in the UK?

Crocosmia × crocosmiiflora 'Sprowston Glory' 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 'Sprowston Glory'?

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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