Crop type: Leeks
Allium porrum ‘Oarsman’ AGM
Common name: Leek ‘Oarsman’ AGM
Crop slug: leeks
This Allotment Pro editorial draft summarises the cited RHS cultivar profile. Check the source and adjust cultivation decisions for local conditions.RHS cultivar profile
1 - Overview
‘Oarsman’ is a hardy perennial leek normally grown as an annual vegetable. This F1 hybrid has thick, upright blue-green leaves and gives a good yield of uniform, straight, smooth stems. It can be harvested from October, depending on sowing time, and keeps well in the ground.
The cultivar is taller than compact leeks, with a conspicuously straight pale shank and vigorous blue-green leaf fan. The RHS profile displays an Award of Garden Merit and lists the name as accepted.
2 - Size
- Ultimate height
- 0.5–1 metre
- Ultimate spread
- 0.1–0.5 metre
- Time to ultimate size
- 1 year
Allow vertical room for its vigorous leaves while maintaining normal leek spacing. Uniform seedlings and steady care support straight, consistently sized stems.
3 - Growing conditions
- Suitable soils
- Chalk, clay, loam or sand
- Moisture
- Moist but well-drained
- Soil pH
- Acid, neutral or alkaline
Use soil rich in organic matter that supplies continuous moisture without waterlogging. The broad texture and pH tolerance makes preparation and rotation more important than a narrow soil specification.
4 - Position and hardiness
- Light
- Full sun or partial shade
- Aspect
- East-, south- or west-facing
- Exposure
- Exposed or sheltered
- Hardiness
- H5 — hardy in most places throughout the UK, even in severe winters
Full sun is preferred, though partial shade is tolerated. H5 hardiness and good ground-holding ability suit extended winter harvesting.
5 - Colour and seasonal interest
Thick upright leaves develop a blue-green cast from summer into winter above uniform smooth white shanks. The leaves remain evergreen through its harvest period. A saleable first-year plant should show no flower head.
6 - Botanical details
- Family
- Amaryllidaceae
- Native to Great Britain and Ireland
- No
- Foliage
- Evergreen
- Habit
- Clump forming
- Name status
- Accepted
Genus
Allium species have a characteristic onion or garlic scent, linear or cylindrical basal leaves and, when flowering, star- or bell-shaped blooms gathered into an umbel.
Safety
No specific handling warning is listed. Clean the roots and overlapping leaf bases thoroughly before cooking.
7 - How to grow
Cultivation
Grow in moist but well-drained soil rich in organic matter, preferably in full sun. Partial shade is acceptable. For longer white stems, draw soil around the shanks in late summer and early autumn without filling the leaf fans.
Keep moisture even while the straight stems expand. Harvest can begin in October, while sound remaining plants may stand for later use.
Propagation
Propagate by seed. Raise and transplant an even batch for uniform straight stems.
Suggested locations
- Winter vegetable plot
- Open allotment row
- Raised bed
- Partial-shade productive bed
Pruning
No pruning is required. Remove damaged leaves and any premature flower stalk only.
Pests
May be susceptible to slugs and snails, leek moth, onion fly and onion thrips.
Diseases
May be susceptible to leek rust, onion white rot, downy mildews, foot and root rots, fungal leaf spots and smuts.