Spinach

**Sowing:** Spinach is direct-sown ¼ to ½ inch deep in early spring as soon as the soil can be worked, in rows 12 to 18 inches apart, then thinned to 2 to 6 inches between plants; because seedlings resent root disturbance, transplanting is only recommended when spring soil stays too wet to sow directly. Sowing small batches every one to three weeks extends the harvest, and a second planting after the worst summer heat gives a fall crop.

**Site and care:** It grows best in full sun to partial shade, in fertile, well-drained soil rich in organic matter with a near-neutral to slightly alkaline pH, and needs consistent, even moisture because its shallow, though eventually long-taprooted, system dries out quickly and triggers premature flowering. Mulching conserves soil moisture and suppresses weeds, and watering the soil rather than the leaves helps limit fungal problems.

**Pests:** Spinach can be attacked by aphids, cutworms, cabbage loopers, corn earworms, diamondback moth caterpillars, and leafminers, the latter identifiable by tunneling in the leaf tissue and best managed by covering plants with row covers or netting and removing mined leaves. Slugs, snails, and sow bugs are also drawn to damp soil surfaces around the plants.

**Diseases:** Downy mildew, white rust, and seedling damping-off affect spinach, with damp, saturated soil and moisture lingering on leaves favoring crown and lower leaf rot as well as leaf spot diseases.

**Bolting:** Increasing day length and warm temperatures, along with drought stress or overly close spacing, cause spinach to send up a flowering stalk; once bolting begins, leaf growth stops and the leaves turn bitter.

**Picking:** Leaves can be harvested at any size, either by snipping outer leaves at their base to leave the crown intact for continued growth, or by cutting whole plants once they reach about 4 to 6 inches with several leaves; harvesting before the plant sends up a flower stalk keeps the leaves from turning bitter.

**Storage:** Harvested leaves are washed and kept in the refrigerator crisper, where they stay usable for a few days to as long as two to three weeks under cool, humid conditions, and they can also be blanched and frozen for longer keeping.

**Culinary:** Spinach leaves are eaten both raw in salads and cooked, valued as a leafy green vegetable. Raw leaves contain oxalates that can interfere with iron and calcium absorption, and cooking the leaves in several changes of water reduces oxalate levels.

**Ornamental:** Varieties with dark green, savoyed or curly leaves are also grown for their handsome texture in edible landscaping.

Spinach is native to a region stretching from central Asia to southwest Siberia and is thought to have first been cultivated in Afghanistan and Tajikistan, with no known wild-growing populations. Its name traces to a Persian word meaning 'green hand,' reflecting cultivation in Iran more than 2,000 years ago; from there it spread into Europe by the 1400s and was carried to America by early settlers, appearing in American seed catalogues by 1806.