Fava Bean

Fava beans (Vicia faba) occupy a different schedule than most garden vegetables - they are a cool-season crop that thrives when tomatoes and cucumbers would freeze, which means they either extend your productive season into territory that most home gardens leave empty, or they crowd out nothing because you’d have bare ground anyway. In zones 7 and warmer, fall-planted favas overwinter and produce a spring harvest. In zones 4-6, plant them as early as the ground can be worked in spring - they can handle frost to about 20°F.

Beyond the edible harvest, fava beans are one of the most efficient nitrogen-fixing crops in the garden. They fix 100-150 lbs of nitrogen per acre under good conditions (University of California Cooperative Extension, Cover Cropping in California Agriculture, ANR Publication 3353). Chopped and incorporated into the soil after harvest, they function as a significant green manure application. This is a crop that pays you twice.

What it actually is

Fava bean (also called broad bean or horse bean) is a member of the legume family (Fabaceae), one of the oldest cultivated crops in the world. It is a distinct genus from common beans (Phaseolus) and soybeans (Glycine) - the right rhizobium inoculant for fava bean is Rhizobium leguminosarum bv. viciae, different from the inoculant used for garden beans or soybeans.

Plants grow 2-5 feet tall, producing thick, upright stems that often need staking in windy locations. Pods are 4-8 inches long, thick-walled, and contain 4-6 large, flat beans surrounded by a padded white lining. The beans themselves are covered in a tough outer seed coat that is removed before eating in mature beans but edible in very young ones.

Variety selection shapes your result. ‘Aquadulce Claudia’ is a long-pod Spanish variety excellent for fall planting; ‘Windsor’ is a standard large-seeded English type; ‘Broad Windsor’ is the most widely available in the US; smaller-seeded types like ‘Ianto’s Return’ and ‘Aprovecho Select’ are better cover crop choices when food harvest is secondary.

The ROI case

Fresh shelled fava beans retail at $4-6/lb at specialty grocers and farmers markets (USDA AMS Specialty Crop Market News, 2023). In much of the US, they are an upscale or specialty item not widely available in standard grocery stores - a farmers market advantage. A $3.49 seed packet covers a 15-20 foot row. Conservative yield estimates for well-managed favas are 1 lb of shelled beans per 3-4 feet of row in a good season.

The nitrogen-fixing value adds a secondary return that doesn’t show up as revenue but reduces your fertilizer costs for subsequent crops. Incorporating the plants after harvest rather than composting them returns that nitrogen directly to the bed where you need it.

Growing requirements

The critical rule: fava beans do not tolerate summer heat. Temperatures above 80°F during pod fill cause flower abortion and poor pod set. The crop window is fall through spring in warm climates, and early spring through early summer in cold climates. Trying to grow favas in summer heat is a waste of seed.

Zone 7 and warmer: Plant in September-November for a late winter to spring harvest. Plants survive light freezes (to about 20°F) but need protection below that. In zones 9-10, favas grow as a winter annual with a January-March harvest window.

Zones 4-6: Plant in early spring as soon as the soil can be worked, typically 4-6 weeks before last frost. Plants handle spring frosts well. Harvest in June before summer heat arrives.

Sow seeds 1-2 inches deep, 4-6 inches apart, in rows 18-24 inches apart. Germination in 7-14 days at soil temperatures of 45-75°F - favas germinate in colder soil than most vegetables. Inoculate seeds with fava bean-specific rhizobium inoculant for maximum nitrogen fixation.

Soil pH of 6.0-7.0. Average soil fertility works - avoid high nitrogen, which reduces nitrogen fixation efficiency. The plant makes its own. Apply phosphorus and potassium if soils are deficient; nitrogen application before the plant establishes root nodules can set nitrogen fixation back.

Water at 1 inch per week. Favas are moderately drought-tolerant in cool weather but need consistent moisture during pod fill. In fall-planted crops, rain typically covers most water needs until spring.

Pinch out the growing tip after 4-5 sets of pods have formed - this concentrates plant energy into pod development rather than continued stem growth and reduces black aphid pressure (aphids strongly prefer the tender growing tip).

What goes wrong

Black bean aphid (Aphis fabae) is the primary pest of fava beans and prefers the growing tip. Colonies can be enormous in spring. Pinching the tip (see above) removes the aphids’ preferred feeding site and is the most effective cultural control. Ladybeetles and parasitic wasps provide significant natural control; avoid broad-spectrum insecticide applications that kill beneficials.

Chocolate spot (Botrytis fabae) causes brown spots on leaves and pods, particularly in wet, cool conditions. Remove infected tissue, improve airflow by spacing plants adequately, and avoid overhead irrigation. Copper-based fungicides can slow the spread; they don’t cure established infections.

Broad bean rust (Uromyces viciae-fabae) produces orange-brown pustules on leaves and stems. Most damaging in warm, humid late-season conditions. Remove affected leaves and apply sulfur fungicide preventively. Crop rotation reduces overwintering rust inoculum.

Favism risk: A small percentage of people (primarily of Mediterranean, Middle Eastern, or African descent) have a genetic enzyme deficiency (G6PD deficiency) that makes them sensitive to compounds in fava beans - consumption can cause a hemolytic crisis. This is worth flagging as an edge case. If you have G6PD deficiency or are unsure, consult a physician before eating fava beans.

Harvest and storage

For fresh shell use: harvest when pods are well filled and beans inside feel firm to the touch, but pods are still green and the beans are not yet fully mature. This is the earliest stage - 60-70 days from planting for early varieties. At this stage the outer seed coat is thin and tender; most people eat the whole bean.

For larger, more mature beans: harvest at full size but before pods yellow. The outer seed coat becomes tougher at this stage; blanch in boiling water for 1-2 minutes, then slip the skins off. The peeled bean underneath is bright green and has better flavor than the unpeeled mature bean.

Fresh shelled favas keep 3-4 days refrigerated. Blanch and freeze for longer storage: 3-4 minutes, ice bath, freeze in bags. Keeps 10-12 months.

For green manure use: turn plants under at or just after harvest. Cut plants at ground level with a spade or hoe rather than pulling to leave the nitrogen-rich root nodules in the soil.

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Related crops: Garden Pea, Arugula

Related reading: Cover Crops 101 - how fava beans and other legumes work as nitrogen-fixing cover crops with an edible bonus