How to Grow Crocosmia
Crocosmia × crocosmiiflora
Crocosmia is a vigorous, clump-forming perennial that thrives in full sun or light shade and most well-drained soils. Plant corms in spring about 8–10 cm deep and enjoy fiery sprays of flowers from mid to late summer. Clumps spread readily and may need dividing every three to four years to maintain vigour and prevent overcrowding. Most varieties, especially 'Lucifer', are reliably hardy across the UK, though a winter mulch helps in colder areas.
Yearly Lifecycle
Care Essentials
Mulch with compost in spring. Rarely needs additional feeding.
Watch For
- Red spider mite
- Generally pest-free
Companions
Grasses, Rudbeckia, Echinacea, Verbena
Track your Crocosmia care schedule — pruning, feeding, and seasonal tasks
Start planning freeCare Requirements
☀️ Light
Full sun for best flowers
Full sun for the best flowering. Tolerates light shade but produces fewer blooms and weaker stems.
💧 Watering
Water in dry spells during growth and flowering
Water during dry spells in the growing season, especially while flowering. Reduce watering after foliage dies back in autumn.
🌱 Fertilizing
Spring compost mulch; rarely needs more
Mulch with compost in spring. Crocosmia is vigorous and rarely needs additional feeding in reasonable soil.
✂️ Pruning
Let foliage die back; divide every 3-4 years
Leave foliage to die back naturally in autumn to feed the corms. Cut back dead leaves in late autumn or early spring. Divide congested clumps every 3-4 years.
🍂 Mulching
Winter mulch in cold or exposed areas
In exposed or northern gardens, apply a thick mulch of bark or straw over the corms in late autumn to protect against hard frosts.
Growing Tips
Plant in a sunny, well-drained spot
Crocosmia flowers best in full sun with reasonably fertile, well-drained soil. It tolerates light shade but produces fewer blooms.
Divide congested clumps
Lift and divide clumps every 3–4 years in spring to maintain flowering vigour and prevent them from becoming invasive.
Leave foliage to die back naturally
Allow the strappy leaves to yellow and wither before cutting back in late autumn. This feeds the corms for next year's display.
Mulch in cold areas
In exposed or northern gardens, apply a thick mulch of bark or straw over the corms in late autumn to protect against hard frosts.
Pests & Diseases
Pest Red Spider Mite
Identification: Fine webbing on leaf undersides; leaves develop a mottled, bronzed appearance; tiny mites visible with a hand lens
- Increase humidity by misting foliage regularly
- Introduce the predatory mite Phytoseiulus persimilis in enclosed spaces
- Spray with a fatty acid-based insecticide, ensuring good coverage of leaf undersides
Pest Gladiolus Thrips
Identification: Silvery streaking on leaves and flower buds; distorted flowers; tiny dark insects visible in flower heads
- Remove and destroy heavily infested flower heads
- Encourage predatory insects such as lacewings
- Spray with a pyrethrin-based insecticide when thrips are first noticed
Disease Crocosmia Mosaic Virus
Symptoms: Yellow streaking and mottling on leaves; stunted growth; reduced flowering
Treatment: No cure; remove and destroy affected plants to prevent spread
Prevention: Buy healthy stock from reputable suppliers; control aphids which spread the virus
Disease Corm Rot
Symptoms: Soft, mushy corms when lifted; poor or no spring growth from affected corms; foul smell
Treatment: Discard affected corms; dust healthy corms with sulphur before replanting
Prevention: Ensure well-drained soil; avoid waterlogged conditions over winter; lift and store corms in cold, wet areas
Popular Varieties
Lucifer, Emily McKenzie, George Davison, Solfatare, Star of the East, Norwich Canary
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