Quinoa

What it is. Quinoa is an upright annual that grows about 5 to 8 feet (1.5 to 2.5 m) tall and 4 to 20 inches (10 to 50 cm) across. Its leaves may turn shades of red and purple as they age, and small greenish flowers form dense clusters before the edible seeds appear. Quinoa is a traditional food in South America and is grown commercially in parts of the United States.

When and how to sow. Plant in spring in a fine seedbed, at a shallow depth of about ¼ inch (0.6 cm). Quinoa planted too deeply will come up poorly. Choose a spot in full sun with moist but well-drained, moderately fertile soil. Early spring planting is favored, but fields with standing water from spring rain should wait, since quinoa does not thrive with excess soil moisture. In favorable conditions, seedlings usually emerge within a week of planting. Weeds are a real challenge, because no selective herbicides are labeled for quinoa, so cultivation and hand weeding are usually needed.

Watering. In the trials, plots were irrigated every 7 to 10 days through the soft-dough stage of seed development. Avoid keeping the soil waterlogged, since quinoa does not do well with excessive moisture.

Heat. Many varieties will not produce seed if summer temperatures rise above 95 °F (35 °C) during flowering and early seed set. Insects. Lygus bugs feed on developing seeds and can greatly reduce yields. Rain at harvest. Mature seed left in the field when fall rain starts will sprout and can ruin the crop.

Timing. Seed is ready when it feels hard when pressed with fingers, though the plants may still be upright and moist in the stems and leaves. Varieties take 100 to 120 days to reach full maturity. Harvest before fall rain arrives, because mature seed left in the field will sprout. Smaller growers have cut the plants, dried them on tarps, and then threshed them by hand.

Raw seeds. Don’t eat raw quinoa seeds, because the saponins in the seed coat make them bitter and inedible until they are removed. Seeds meant for food need processing to remove the saponins before eating.