General
Broad bean (Vicia faba) is a cool-season legume grown for its large, protein-rich seeds. It tolerates cold and light frost and is well-suited to northern climates. Plants are upright with sturdy square stems and white or black-and-white flowers. Varieties vary: long-podded types for fresh green beans, small-seeded ‘field bean’ types for drying, and compact cultivars suited to windy or exposed plots. Early sowings produce earlier harvests and help evade peak black aphid pressure.
Light
Full sun to light partial shade; 6–8 hours of sun is ideal.
Soil type
Moisture-retentive but well-drained loam or clay-loam enriched with compost; avoid waterlogging.
Water requirement
Moderate; keep evenly moist, especially during flowering and pod fill.
Nutrient requirement
Low to moderate. As a legume it fixes nitrogen; excess nitrogen leads to lush foliage with fewer pods.
Precultivation
For the earliest crops, sow indoors in deep modules or root trainers 3–5 cm deep from mid-March to mid-April at 10–15°C. Keep cool and bright to prevent legginess. Harden off for 7–10 days before planting out once day temperatures hold above ~5°C. Direct sowing is reliable once soil is workable and above ~5°C; pre-germinating seeds on moist paper for 24–36 hours can speed emergence in cold soils.
Planting
Direct sow or transplant in double rows 20–25 cm between plants with 45–60 cm between rows (or paired double rows with a 60–70 cm path). Sow 5–7 cm deep. In windy sites, support with strings between stakes along row edges. Mulch after establishment to conserve moisture and suppress weeds. Broad beans prefer pH 6.0–7.5 and benefit from autumn-applied compost. Avoid fresh manure.
Pruning
Pinch out the growing tips when the first pods have set (typically June–July) to reduce black bean aphid pressure and to focus energy on pod development. Remove storm-damaged stems at ground level; plants will often branch from the base.
Maintenance
Water deeply during flowering and pod fill. Keep beds weed-free. Side-dress lightly with compost or a low-N, balanced organic fertilizer in spring; avoid high-nitrogen feeds. Provide wind protection or staking for tall varieties. Floating row cover or fleece can protect early sowings from cold snaps and birds. Inoculation with Rhizobium is usually unnecessary in established soils but may help in new beds.
Harvest
Harvest young pods for whole-pod eating when seeds are just forming. For classic shelled beans, pick when pods are well-filled but still green and glossy—taste is sweetest before seed coats toughen. For dry beans, leave pods on the plant until they rattle and turn brown; then harvest and finish-dry under cover before shelling. Regular picking encourages continued pod set.
Common issues
Black bean aphid clusters on shoot tips—pinch out tips, encourage beneficials, and use a strong water spray; avoid overfeeding with nitrogen. Chocolate spot (Botrytis fabae) causes brown lesions—reduce humidity with generous spacing, avoid overhead watering, and remove infected debris. Rust and downy mildew appear in humid spells—choose resistant varieties and rotate. Birds and mice may pull seedlings—use fleece or netting. Frost may nip flowers; plants usually recover and set later flushes.
Rotation schedule
Rotate on a 4–6-year cycle away from other legumes to reduce soil-borne disease and pest buildup. Follow with heavy feeders (e.g., brassicas) to take advantage of residual nitrogen.
Pollination
Mostly self-fertile but insect-pollinated; flowers attract bees and bumblebees and benefit from cross-pollination.
Companion plants
Brassicas, carrots, potatoes, dill, strawberries, spinach, marigold (Tagetes), nasturtium.
Incompatible plants
Onion, garlic, leek (alliums), fennel; avoid planting immediately after other legumes.
