How to Grow Spinach From Seed

Spinach is a cool-season crop, so timing is everything. Sow seeds directly in the garden 4 to 6 weeks before your average last spring frost, as soon as the soil can be worked. Spinach shrugs off light frost, so an early start is an advantage rather than a risk.

For a second harvest, sow again in late summer once the worst heat has passed, about 6 to 8 weeks before your first fall frost. Fall crops often taste sweeter after a light frost. In mild-winter regions you can overwinter a late-fall sowing under row cover for very early spring greens.

Spinach is direct-sown, not transplanted, because it resents root disturbance. Loosen the top few inches of soil and work in some compost so it drains well but stays moist.

• Depth: sow seeds about half an inch deep.
• Spacing: drop seeds roughly 2 inches apart in rows 12 to 18 inches apart, or broadcast over a wide band.
• Thin: once seedlings have a couple of true leaves, thin to 3 to 6 inches apart and eat the thinnings.
• Sun and soil: full sun in cool weather, part shade as it warms; rich, moist, well-drained soil with a near-neutral pH.
• Water: keep the seedbed consistently damp until germination, which takes 7 to 14 days in cool soil.

Spinach grows fast and needs steady moisture and nitrogen to make tender leaves. Give it about an inch of water a week and a light feed of a balanced or nitrogen-forward fertilizer a few weeks after the seedlings are up. Mulch helps hold moisture and keeps the soil cool, which delays bolting.

Watch for leaf miners tunneling inside leaves, aphids on the undersides, and downy mildew in cool damp spells. A floating row cover keeps leaf miners and other pests off, and good spacing with airflow limits mildew.

Climate note: In cool-summer areas like the Pacific Northwest, New England, and the upper Midwest, spinach is a long, forgiving spring and fall crop. In hot regions like Texas, Florida, and the Deep South, treat it strictly as a fall-through-winter green, since spring warmth pushes it to bolt by May; a fall sowing there can crop right through winter.

Spinach is an easygoing neighbor in a cool-season bed. These companions help it along by loosening soil, drawing pests away, and bringing in beneficial insects. Since spinach is a low, quick green, pair it with plants that share its spring and fall window.

You can start harvesting as soon as leaves are big enough to use, often around 30 days for baby leaves and 40 to 50 days for full-size ones. Pick the outer leaves first and leave the central crown, and the plant keeps producing for weeks.

For a bigger pick, cut the whole plant about an inch above the soil; it will often regrow for a second cutting. Harvest in the morning when leaves are crisp, and once a plant sends up a flower stalk, pull it, since the leaves will only get more bitter.

Spinach is at its best raw and fresh. Toss baby leaves straight into salads, layer them on sandwiches, or blend a handful into a smoothie. Larger leaves are better wilted or cooked, since a quick saute with garlic or a fold into soups, pasta, and eggs mellows their flavor.

It also freezes well: blanch briefly, squeeze out the water, and freeze in portions for winter cooking. Growing your own means you can pick it minutes before it hits the pan, when the flavor and texture are at their peak.

Bolting: triggered by heat and long days; sow early, keep plants cool and watered, and choose bolt-resistant varieties.

Poor germination: usually soil that is too warm; spinach germinates poorly above 75F, so sow in cool spring or fall soil, or pre-chill seed.

Leaf miners: pale tunnels inside leaves; use row cover and remove affected leaves promptly.

Yellowing leaves: often low nitrogen or uneven watering; feed lightly and keep moisture steady.