Overview
Crocosmia masonorum 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 masonorum 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.
About
Crocosmia masonorum is a clump-forming perennial in the iris family with upright growth and arching flower sprays. It has deciduous, stiff, pleated, sword-shaped leaves of mid to bright green. Flowering occurs from July to September. Plant in a sheltered, south-, west- or east-facing spot in fertile, moisture-retentive loam.
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 masonorum sits within the iris family and forms upright clumps that produce arching sprays of flowers through mid to late summer. The foliage is deciduous and the leaves are stiff, pleated and sword-shaped, providing a structural presence in the border until they die back after the flowering season. Give Crocosmia masonorum full sun to partial shade on a fertile, moisture-retentive loam improved with organic matter and ensure soils remain moist but well drained; it tolerates acid, neutral or alkaline pH. Position the plants in a sheltered spot on a south, west or east aspect to reduce wind damage to the arching stems. The hardiness rating H4–H6 indicates average to very hardy behaviour, so it will withstand typical UK winters in most districts when established. Use it where upright form and late-summer bloom are needed: planted among summer perennials it provides vertical rhythm and a sequence of flowers from July to September. The clump-forming habit makes it suitable for grouping in borders where the sprays can be shown off rather than crowded into narrow spaces. Expect the pleated leaves to persist through the flowering months and to die back afterwards.
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 masonorum 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
Care notes
Pruning and caring for Crocosmia masonorum
- 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 masonorum?
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 masonorum?
Crocosmia masonorum prefers full sun to partial shade. It suits sheltered positions.
What soil does Crocosmia masonorum need?
Crocosmia masonorum 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 masonorum?
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 masonorum hardy in the UK?
Crocosmia masonorum 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 masonorum?
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
- Crocosmia × crocosmiiflora 'A. E. Amos'Montbretia
- Crocosmia × crocosmiiflora 'Aurore'Montbretia
- Crocosmia × crocosmiiflora 'Carmin Brilliant'Montbretia
- Crocosmia × crocosmiiflora 'Emily McKenzie'montbretia 'Emily McKenzie'
- Crocosmia × crocosmiiflora 'Firebird'Montbretia
- Crocosmia × crocosmiiflora 'Golden Glory'Montbretia
- Crocosmia × crocosmiiflora 'His Majesty'montbretia 'His Majesty'
- Crocosmia × crocosmiiflora 'Jackanapes'montbretia 'Jackanapes'