About
Allium cepa is the foundational species from which numerous cultivars of onion, shallot, and spring onion have been developed. It features hollow, fleshy leaves that are green or blue-green and can be consumed when they are young. The bulb's size, shape, and color will differ based on the specific cultivar.
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, Clay, Loam, Sand
- Soil pH
- Alkaline, Neutral
- Soil moisture
- Moist but well-drained
- Aspect
- East-facing, North-facing, South-facing, West-facing
- Exposure
- Exposed, Sheltered
- UK hardiness
- H4
Plant details
- Plant type
- Herbs - Culinary, Bulbs
- Habit
- Clump forming
- Foliage
- Deciduous
- Height
- 0.1-0.5 metres
- Spread
- 0.1-0.5 metres
- Time to full height
- 1 year
Care notes
- Cultivation
- Grow in fertile, moisture retentive, but well-drained soil in full sun. Thin-out young plants growing from seeds in spring. Yellowing and toppling of the foliage is a sign that the shallots are reaching maturity. Lift and store in a cool dry place. See how to grow: onions for further advice
- Pruning
- No pruning required
- Propagation
- Propagate by seed or by onion sets. See how to grow: onions or sowing vegetable seeds
- Pest resistance
- May be susceptible to onion fly, leek moth and narcissus eelworm
- Disease resistance
- May be susceptible to onion white rot, onion downy mildew, leek rust and onion neck rot. Bolting, producing flowers, may be a problem