About
Allium carolinianum is a bulbous perennial characterized by its flat, strap-like, mid-green foliage. In late spring and early summer, it produces compact spherical clusters of flowers, which can be pale red, purple-red, or white, atop upright stems reaching up to 40 cm in height.
About the genus
Allium consists of bulbous herbaceous perennials characterized by a pronounced onion or garlic aroma. They feature linear, strap-like, or cylindrical leaves that arise from the base. The flowers, which can be star-shaped or bell-shaped, are arranged in an umbel atop a stem that lacks leaves.
Growing conditions
- Sunlight
- Full sun
- Soil type
- Chalk, Loam, Sand
- Soil pH
- Acid, Alkaline, Neutral
- Soil moisture
- Moist but well-drained, Well-drained
- Aspect
- South-facing, West-facing
- Exposure
- Sheltered
- UK hardiness
- H6
Plant details
- Plant type
- Bulbs
- Habit
- Clump forming
- Foliage
- Deciduous
- Height
- 0.1-0.5 metres
- Spread
- 0-0.1 metre
- Time to full height
- 1-2 years
- Suggested uses
- City and courtyard gardens, Coastal, Cottage and informal garden, Gravel garden, Patio and container plants, Wildlife gardens
- Fragrance
- Foliage
- Toxicity
- TOXIC to pets - see the HTA guide to potentially harmful plants for further information and useful contact numbers
Care notes
- Cultivation
- Grow in full sun and fertile well-drained soil. It is best to grow in containers where garden soil is heavy clay and prone to saturation over winter. See allium cultivation
- Pruning
- No pruning required, other than to remove old flowered stems and foliage
- Propagation
- Propagate by offsets which can be carefully detached by lifting the bulb after flowering has finished. See bulb propagation
- Pest resistance
- May be susceptible to allium leaf miner and onion fly
- Disease resistance
- May be susceptible to onion white rot, and onion downy mildew