Black Bean

Black beans are a dry-seed type of the common bean, Phaseolus vulgaris. They belong to the same species as green beans. Beans are tender annuals, and frost damages their tissue. Plants may climb, trail, or grow in a bush form.

Sowing. Sources differ on timing. One says to sow after the danger of frost has passed. Another says to start planting one week before the last frost-free date. Sow once the soil is above 60 °F (16 °C). Seedlings emerge in about 7 to 10 days when the soil is 65 to 85 °F (18 to 29 °C).

Depth and spacing. Cover the seed with ¼ to ½ inch (6 to 13 mm) of soil or compost. Another guide advises planting 1 inch (2.5 cm) deep. Space seeds 2 to 3 inches (5 to 8 cm) apart in rows 18 to 24 inches (46 to 61 cm) apart. No thinning is needed if the plants come up too thick.

Light and support. Give them full sun. Bush types don’t need support, but pole types need a trellis. Trellises should be 6 to 8 feet (1.8 to 2.4 m) tall and sturdy.

Water. Keep the soil evenly moist, especially during flowering. Avoid soggy soil, because wet conditions promote root rot. Organic mulch helps conserve water.

Feeding. Beans don’t need extra fertilizer if compost and an all-purpose fertilizer went in at planting. Too much nitrogen delays flowering and reduces pod set. Beans get nitrogen from soil bacteria on their roots. For dry beans, inoculating the seed helps if beans haven’t been grown in the field recently. Black and navy beans are more sensitive to iron deficiency than pinto or great northern beans.

Common problems include bacterial blight, Cercospora leaf spot, Mexican bean beetles, spider mites, and powdery mildew. Hot weather above 95 °F (35 °C) combined with dry conditions can make plants drop their flowers.

For dry beans, leave the pods on the plant until they are dry and brown. Harvest once the pods are yellow and dry. Pull up the plants, lay them in a row for 5 to 7 days, then remove the pods and shell the seeds. Expect about 20 to 25 pounds (9 to 11 kg) of dry seed per 100 feet (30 m) of row.

For long-term storage, keep dried beans in sealed containers in a cool, dry place.

Don’t eat raw or undercooked dried beans. They can cause severe nausea, vomiting, and diarrhea, and the seeds are the part involved.