Planting Guide and Seed Saving Notes for Spinach

Spinach (Spinacia oleracea)

Spinach, with buttery nutritious leaves and cold hardiness, will never go out of style. It prefers late summer weather as it changes into fall, when days gradually become shorter and the sun rises lower in the sky. Spring plantings are best for baby leaf production as the plants tend to bold quickly with lengthening, hotter days. For best results in spring, over-winter small fall planted spinach plants. They will begin to grow again in late winter and early spring for a tasty harvest.

*Summer Spinach plants are not true spinach, but they will satisfy a mid-summer craving for nutrient dense greens when it’s too hot for most other plants. Summer Spinach is not frost tolerant so be sure to plant these for a summer harvest.

Nutrients: vitamins A, E, K, and C, calcium, iron, magnesium, and potassium. 

How to Grow Spinach from Seed

Bed Preparation

Spinach is a cool season plant that prefers moist, well-drained soil high in nitrogen. Choose a site with full sun to partial shade.

Planting

Seeds germinate best if soaked in water prior to planting. Germination rates are greatly reduced if soil temperatures are above 65˚F. Start seeds as early as six weeks before the last frost or as soon as you can work the soil. Sow seeds ½" deep and 1" apart. Seeds will sprout in 6-21 days. Thin seedlings so that mature plants are 4" apart.

Spinach can be planted in succession every two weeks throughout spring and again in late summer for a fall crop. With minimal protection, spinach overwinters in most areas of the U.S.

Harvest

Harvest when plants have at least six 3-4" long leaves. Harvest by cutting leaves from the outside of plant first to prolong productivity.

How to Save Spinach Seeds

Hot temperatures and long days will trigger flowering in spinach. Allow spring crop to flower and set seed. Seed is ready to harvest when the flowers have dried brown and seeds are black. Spinach seeds do not store for extended periods of time. Fresh seed should be used each growing season.