Growing spinach—you can keep harvesting this cold-hardy plant until the first frost
Spinach grows faster in a pot or raised bed in a sunny spot than in a garden bed. Soaking seeds in water or keeping them in moist sand speeds up germination—and the harvest. Remember to water the seedlings well so you get luscious leaves.
Growing spinach—how to succeed
Location
You can grow spinach in a pot on a windowsill or outdoors, in a box or in a bed. When grown early or in cool weather, a garden fleece, protective tunnel, covered box, or greenhouse can speed up growth.
Soil
Prepare loose, moisture-retaining, limed, and fairly nutrient-rich soil for spinach. Avoid excessive nitrogen fertilization, as spinach tends to accumulate nitrates. Generally, a basic fertilizer application is enough for the entire growing season.
Spinach sowing and seed starting
Sow seeds in spring and late summer. Spinach sown in summer often grows a tall flower stalk quickly, and the flavor becomes woody.
You can speed up the germination of the hard-coated seeds by soaking them in water for a day or keeping them in moist sand for a couple of days. You can also start the seedlings in small pots, sowing a few seeds per pot.
Sow seeds 1–1.5 centimeters deep, either by broadcasting, or in rows that are about 15 centimeters apart. Keep the soil moist and water the seedlings regularly.
Fall sowing spinach
If you want to do fall sowing, wait until late fall or early winter, because spinach can germinate at temperatures as low as around zero degrees Celsius. You can also sow seeds in March–April in a bed or box you prepared the previous fall.
Sow spinach early in spring or in late summer so it doesn’t flower. Varieties differ in their tendency to bolt.
Growing spinach in a pot
- Spinach grown in a pot produces a quick harvest. Choose a pot or box with drainage holes and preferably 20–30 centimeters deep. A thin layer of soil dries out quickly in warm weather.
- Broadcast the seeds fairly densely. If the weather is cool, move the container to a warm spot to speed up germination. You can also cover the sowing with garden fleece. Spinach seeds germinate fastest at about 20 degrees Celsius, taking 5–15 days to sprout.
- Keep the pot in a bright place, preferably sheltered from rain, as the splashing can muddy the leaves.
Thinning
Thin your spinach by harvesting small seedlings. Leave the rest 5–10 centimeters apart and gradually harvest the largest leaves, about four centimeters long.
Harvest
You’ll get baby leaves in less than a month. Hardened-off spinach can withstand subzero temperatures up to a few degrees Celsius, so you can keep harvesting well into fall.
Spinach varieties:
- ‘Red Tabby’ F1, ‘Red Kitten’ F1, ‘Reddy’ F1: These ornamental varieties have red leaf veins and stems.
- ‘Lazio’ F1, ‘Puma’ F1, ‘Renegade’ F1, and ‘Palco’ F1: Recommended for growing in pots and as baby leaf spinach.
- ‘Thorin’, ‘Giant America’, ‘Vroeg Reuzenblad’, ‘Corvair’ F1, and ‘Viroflex’: Available as organic and biodynamic seeds.
- ‘Monstrueux de Viroflay’: An heirloom variety from 1866. Its leaves have a low oxalic acid content.
- ‘Mikado’ F1: The dark green leaves have a mild flavor and a distinctive shape.
