A cool season annual, organic gardeners are growing spinach for its delicious and nutritious, dark green leaves.
Sunlight: Full sun to partial shade
Maturity: 40-60 days
Height: 6 to 12 inches
Spacing: 3 to 4 inches apart, 12 to 18 inches between rows
Chock-full of vitamins A and B-2, and rich in iron and calcium, spinach is one of the first greens up in the spring with cool weather being the key to its success. Warm temperatures and longer days will quickly trigger spinach to go to seed (bolt).
Spinach requires full sun and regular water and should be planted in rich, fast draining soil. Before planting work in 10-15 pounds of organic garden compost per 100 sq ft to a depth of 8 inches. Work the soil thoroughly, taking care to break up any large clumps. Rocks should be removed from the planting area. Add a source of organic nitrogen, such as blood meal or alfalfa meal, to promote rapid growth.
How to Plant:
Sow seed directly into the ground, 1/2 inch deep in early spring or late fall. Thin seedlings to 6 inches apart when they are 4 to 5 inches tall. Spinach likes water — keep the soil evenly moist but not wet. Constant moisture promotes rapid growth and helps prevents bolting. Mulching with compost will help deter weeds and prevent moisture loss. Fertilize with Dr. Earth Nitro Big or other organic fertilizer when plants have four true leaves.
Harvest young plants or allow plants to mature and harvest outer leaves. Spinach will reach maturity 40 to 60 days after planting from seed. Harvest young spinach for the best flavor and watch for hot weather as it will cause plants to bolt or go to seed. Cover with shade cloth if temperatures exceed 80˚F.
Insects and Diseases:
Floating row cover can be used when temperatures are cool to protect plants from many caterpillar and beetle species. Remove covers as soon as temperatures begin to warm. Keep and eye out for flea beetles early in the gardening season. They are small (1/10 inch long), shiny, dark brown or black beetles that damage plants by chewing numerous small holes in the leaves. Occasional aphids may attack, however this will typically occur later in the season when the plant is less appealing.
Seed Saving Instructions:
Spinach will cross-pollinate with wind-blown pollen from other spinach varieties. Commercial seed crops are separated by 5 to 10 miles to ensure purity, but home gardeners can reduce that distance. Harvest seeds when they are completely dry on the plant. It may be necessary to wear garden gloves because the seed can be very prickly.