Crop type: French Beans
Phaseolus vulgaris ‘Cobra’ PBR
Common name: Bean (climbing French) ‘Cobra’
Crop slug: french-beans
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
‘Cobra’ is a vigorous, reliable climbing French bean that reaches the top of its support quickly and begins producing ahead of many alternatives. It is noted for yielding roughly a third more beans than other varieties and continuing a heavy crop over a long season.
Its smooth, round green pods grow to about 18cm (7in). They are stringless, sweetly flavoured and particularly valued for their eating quality. Pale-violet summer flowers add ornamental interest among the green foliage. The RHS profile displays the Award of Garden Merit and records Plant Breeders’ Rights.
2 - Size
- Ultimate height
- 1.5–2.5 metres
- Ultimate spread
- 0.1–0.5 metre
- Time to ultimate size
- 1 year
The narrow climbing spread gives a high yield from a small footprint. Provide a sturdy vertical support before planting and stop the leader once it reaches the top so later pods stay accessible.
3 - Growing conditions
- Suitable soils
- Clay, chalk, loam or sand
- Moisture
- Moist but well-drained
- Soil pH
- Acid, neutral or alkaline
‘Cobra’ is tolerant of soil type and pH but needs fertile, moisture-retentive ground for uninterrupted flowering and pod filling. Improve light or dry soil with organic matter while retaining drainage.
4 - Position and hardiness
- Light
- Full sun or partial shade
- Aspect
- West- or south-facing
- Exposure
- Sheltered
- Hardiness
- H2 — tolerant of low temperatures but unable to survive freezing
Grow as a tender summer annual after frost. A sheltered position protects the tall vine and pale-violet flowers, while good light supports its early start and prolonged yield.
5 - Colour and seasonal interest
Pale-violet flowers are the cultivar’s ornamental signature, followed by smooth round green pods among deciduous green trifoliate foliage. The harvest-stage pods should be slender and even rather than flat, swollen or visibly seeded, clearly separating ‘Cobra’ from broad-podded ‘Algarve’ and ‘Golden Gate’.
6 - Botanical details
- Family
- Fabaceae
- Native to Great Britain and Ireland
- No
- Foliage
- Deciduous
- Habit
- Climbing
- Name status
- Accepted
Genus
Phaseolus includes annual and perennial legumes with trifoliate leaves and climbing or trailing stems. Members supply French, runner and lima beans, alongside crops for dried seed, animal feed, green manure and ornamental planting.
Safety
Raw pods and beans are harmful if eaten by people or dogs. Cook beans thoroughly. The RHS profile also advises using protective equipment while handling where appropriate.
7 - How to grow
Cultivation
Train the vigorous vine up a stable support in fertile, moisture-retentive soil with good light. Water consistently as flowers open and pods form. Pick the smooth round pods young and regularly to maintain the long continuous crop rather than allowing seeds to swell.
Propagation
Propagate by seed.
Suggested locations
- City or courtyard garden
- Cottage or informal garden
- Patio container with tall support
- Climber or wall planting
- Flower border or edible bed
Pruning
No formal pruning is required. Stop the leader at the support top as a practical training measure and tie back shoots loosened by wind.
Pests
May be susceptible to black bean aphids. Protect young plants from slugs and snails and inspect soft shoot tips for colonies.
Diseases
May be susceptible to chocolate spot, downy mildews, foot and root rot, halo blight and powdery mildews. Use well-drained ground, sensible spacing and clean crop hygiene.