Fava Bean

Fava beans are the opposite of most legumes — they prefer the cold, grow in early spring alongside peas and spinach, and are killed by summer heat rather than frost. In most of the country, the window to grow them is the six to eight weeks between early spring planting and midsummer heat. That's a narrow season, but it's a productive one. While most of the garden is still waiting for warm soil, favas can be knee-high, flowering, and approaching harvest.

Sow seeds directly in the ground about 4 weeks before your last frost — the large seeds germinate in soil as cold as 40°F, though 50 to 60°F is faster and more reliable. Press seeds 1 to 2 inches deep, 6 inches apart, in double rows with 18 inches between rows. They don't need starting indoors. If you've never grown favas or other Vicia legumes in a particular bed, inoculate the seeds with Rhizobium leguminosarum before planting — the nitrogen-fixing bacteria they need to form root nodules may not be present in virgin garden soil.

The plants grow quickly to 3 to 5 feet and will need some support. Staking is easiest done early: run twine along the outside of a double row between stakes at either end, and add a second level as the plants grow. Pinching out the growing tip when the first flowers open can help redirect energy to pod development and may reduce black bean aphid pressure — the soft stem tips are where aphids prefer to feed. The tips are edible and can be sautéed like spinach.

Black bean aphids are the most reliable problem with favas. Dense, black colonies appear on stem tips and can cause the tops to curl and distort. The pinching move helps both as a cultural control and as a way to remove the most heavily infested tissue. A strong jet of water or insecticidal soap can knock aphid populations back, but in a bad year, the infestation can outpace control efforts. Chocolate spot — a fungal disease that causes brown spots on leaves and pods — appears in wet, cool conditions and is worse in densely planted beds. Improve air circulation and avoid overhead watering.

Note on favism: some people with an inherited enzyme deficiency (G6PD deficiency) experience a serious reaction — called favism — from eating fava beans. The condition is most common in people of Mediterranean, Middle Eastern, African, and South Asian descent. If you're not sure whether this applies to you or someone in your household, it's worth checking before consuming.

Harvest beans when the pods are plump and the beans inside have filled out but before the pods start to dry and the skin on the beans turns black. The inner skin on mature beans is tough and bitter; younger beans — smaller than your thumbnail — are tender enough to eat skin and all. For larger beans, blanch briefly and pop the bean from its inner skin. After harvest, cut the plants at ground level and leave the roots — the nitrogen-fixing nodules remain in the soil and break down, benefiting the next crop.