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

Overview

Crocosmia × crocosmiiflora 'Walburton Red' 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 'Walburton Red' 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 naturalizing in moisture-retentive soil..

About

Crocosmia × crocosmiiflora 'Walburton Red' is a clump-forming perennial in the iris family with upright, sword-shaped leaves and arching sprays of flowers. It carries stiff, pleated foliage that dies back after the season. Plant in a sheltered, south-, west- or east-facing spot in moisture-retentive, fertile loam. It flowers from July to September.

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 'Walburton Red' belongs to the Iridaceae and grows as a clump-forming, upright perennial with arching flower sprays and deciduous, pleated, sword-shaped leaves. Flowering occurs from July to September, providing summer into early autumn interest and a run of cut-flower stems. Give it full sun to partial shade in a sheltered position, ideally on a south, west or east aspect. Work organic matter into a fertile, moisture-retentive loam before planting; the cultivar tolerates acid, neutral or alkaline soils provided they remain moist but well drained. Exposure should be sheltered to protect the arching stems from strong winds. Hardiness is H4–H6, which translates to average to very hardy across much of the UK; locate it where winter conditions are not excessively exposed. Use Crocosmia × crocosmiiflora 'Walburton Red' towards the middle or back of borders, in cottage-garden mixes or where you wish to naturalise in moisture-retentive soil. It is also a straightforward source of summer cut flowers, with the arching sprays reliably produced through July to September.

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 'Walburton Red' 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, naturalizing in moisture-retentive soil.

Care notes

Pruning and caring for Crocosmia × crocosmiiflora 'Walburton Red'

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 'Walburton Red'?

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 'Walburton Red'?

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

What soil does Crocosmia × crocosmiiflora 'Walburton Red' need?

Crocosmia × crocosmiiflora 'Walburton Red' 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 'Walburton Red'?

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 'Walburton Red' hardy in the UK?

Crocosmia × crocosmiiflora 'Walburton Red' 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 'Walburton Red'?

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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