By E. VinjeTweet
A cool season annual, organic gardeners are growing spinach for its tasty and nutritious leaves. Chock-full of vitamins A and B-2, and rich in iron and calcium, it is one of the first greens up in the spring. Growing spinach in cool weather is the key to success.
Spinach requires full sun and regular water and should be planted in rich, fast draining soil. Before planting work in 10-15 pounds of 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 growing area. Add a source of organic nitrogen, such as blood meal or alfalfa pellets, 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 4-5 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 fish emulsion or other organic fertilizer when plants have four true leaves.
Tip: To speed germination soak seeds for 15-20 minutes in compost tea.
Harvest young plants or allow plants to mature and harvest outer leaves. Spinach will reach maturity 35-45 days after planting from seed. Harvest young spinach for the best flavor and watch for hot weather as it will cause plants to bolt (go to seed). Cover with shade cloth if temperatures exceed 80 degrees.
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 growing 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 growing season when the plant is less appealing.
Downy mildew and mosaic virus are two common foliar diseases. Select resistant varieties and provide plenty of air circulation to help prevent fungal problems.
Seed Saving Instructions:
Spinach will cross-pollinate with wind-blown pollen from other spinach varieties. Commercial seed crops are separated by 5-10 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 leather gloves because the seed can be very prickly.