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

Overview

Crocosmia × crocosmiiflora 'Queen Alexandra' 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 'Queen Alexandra' 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 sunny spots..

About

Crocosmia × crocosmiiflora 'Queen Alexandra' is a clump-forming perennial in the iris family that carries upright growth topped by arching flower sprays. The foliage is deciduous, with stiff, pleated, sword-shaped leaves of mid to bright green. It flowers from July to September and is valued for summer stems for cutting and border planting. Plants perform best in sunny, sheltered sites with moisture-retentive loam improved by organic matter.

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 'Queen Alexandra' is a perennial in the Iridaceae with a clump-forming habit and upright leaves that carry horizontally arching sprays of blooms. Leaves are deciduous, stiff and pleated; the plant is used where bold, vertical foliage and tall flowering stems are required. It flowers from July to September, producing stems suited to cutting during that period. Place the plant in full sun to partial shade on a south, west or east-facing site with some shelter from prevailing winds. Use fertile, moisture-retentive loam improved with organic matter and ensure conditions are moist but well drained; the plant tolerates acid, neutral or alkaline soils. Hardiness is rated H4–H6, which in UK terms runs from average to very hardy and means it will overwinter outdoors across much of Britain when given a sheltered spot. Plant groups for impact in mixed borders, allow space for the clump-forming habit to spread, or naturalise it in a sunny corner of a cottage garden. It is regularly grown for cut flowers; the arching sprays supply long stems between July and 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 'Queen Alexandra' 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 sunny spots.

Care notes

Pruning and caring for Crocosmia × crocosmiiflora 'Queen Alexandra'

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 'Queen Alexandra'?

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 'Queen Alexandra'?

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

What soil does Crocosmia × crocosmiiflora 'Queen Alexandra' need?

Crocosmia × crocosmiiflora 'Queen Alexandra' 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 'Queen Alexandra'?

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 'Queen Alexandra' hardy in the UK?

Crocosmia × crocosmiiflora 'Queen Alexandra' 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 'Queen Alexandra'?

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

Browse all Crocosmia →