Crop type: Onions
Allium cepa (Cepa Group) ‘Sturon’
Common name: Onion ‘Sturon’
Crop slug: onions
This Allotment Pro editorial draft summarises the cited RHS cultivar profile and its linked crop guidance. Check the sources and adjust cultivation decisions for local conditions.RHS cultivar profile
1 - Overview
‘Sturon’ is a traditional AGM onion valued for reliability. It makes semi-round, straw-coloured bulbs with excellent flavour and good keeping qualities, providing a dependable winter store after a late-summer harvest.
The cultivar can be spring planted for harvest later that summer or autumn planted for a crop the following summer, provided soil drains freely through winter.
2 - Size
- Ultimate height
- 0.1–0.5 metre
- Ultimate spread
- 0.1–0.5 metre
- Time to ultimate size
- one year
Allow 5–15cm between bulbs and 20–30cm between rows. Wider plant spacing encourages larger semi-round bulbs.
3 - Growing conditions
- Suitable soils
- Clay, loam or sand
- Moisture
- Well drained
- Preferred pH
- Neutral
Use fertile ground that retains useful moisture without waterlogging. Improve it with mature compost before planting and avoid fresh manure.
4 - Position and hardiness
- Light
- Full sun
- Aspect
- South- or west-facing
- Exposure
- Sheltered
- Hardiness
- H3
Full sun promotes strong leaves and thorough ripening. Protect young sets from birds with fleece until rooted.
5 - Colour and seasonal interest
Green cylindrical leaves persist through the active growing season above developing bulbs. At maturity the semi-round bulbs are wrapped in pale straw-coloured papery skins. Remove flower stalks because bolting prevents reliable storage.
6 - Botanical details
- Family
- Amaryllidaceae
- Native to Great Britain and Ireland
- No
- Foliage
- Deciduous
- Habit
- Clump forming
- Name status
- Accepted
Genus
Allium contains bulbous herbs with strongly scented cylindrical or strap-shaped basal leaves and star- or bell-shaped flowers arranged in umbels.
Safety
The bulb is edible. Avoid bruising it during lifting so the storage skins remain intact.
7 - How to grow
Cultivation
Grow in fertile, moist but well-drained soil in full sun and shelter. Plant sets in March or April for late-summer harvest, or suitable stock in autumn for harvest the following summer. Place sets about 2cm deep with the point showing.
Water in dry weather during establishment, weed carefully and stop watering once bulbs swell. Lift after the foliage yellows and topples, dry for about two weeks and store in a light, cool, dry ventilated place.
Propagation
Propagate by seed; commercially supplied sets are also used in the linked onion guide.
Suggested locations
- Vegetable bed
- Raised bed
- Allotment row
- Large container
- Sheltered kitchen garden
Pruning
No pruning is required. Remove flower stalks promptly.
Pests
May be susceptible to onion fly. Birds may lift young sets before they root.
Diseases
May be susceptible to onion white rot, leek rust, downy mildew and bolting. Rotate alliums and avoid waterlogged sites.