Spinach is a cool-weather vegetable related to beets and Swiss chard. A fast-growing plant, it yields many leaves in a short time in the mild weather of spring and fall. When growing spinach, the trick lies in making it last as long as possible, especially in the spring, when lengthening days shorten its life. It prefers full sun, but will still produce a respectable harvest in partial shade.
- Plant spinach during the cool weather of spring and fall.
- Space 12 inches apart in fertile, well-drained soil with a pH of 6.5 to 7.0.
- Mix in several inches of aged compost or other rich organic matter into your native soil.
- Check soil moisture often and keep moisture levels consistent.
- Feed regularly with a water-soluble plant food.
- Harvest once leaves are large enough to eat from the outside first.
Growing & Harvesting:
In the spring, plants will grow tall and bloom (called bolting) as soon as the days are longer than 14 hours. Heat also speeds up bolting, since spinach prefers temperatures between 35 and 75 degrees.
Because it bolts in the lengthening days of spring, spinach is an especially popular crop for fall, when days are short and cool. Spinach is one of the most cold tolerant vegetable plants, tolerating temperatures as cold as the teens to low 20s once they are well established. This quality makes them great for overwintering over in zones 8 and southward. So, in cold climates, some gardeners plant spinach in a cold frame or cover plants with hay and leave them all winter; they’ll be first to produce a very early spring harvest.
The leaves are ready to harvest as soon as they are big enough to eat. Harvest by removing only the outer leaves and allowing the center leaves to grow larger; this will allow the plant to keep producing. Picking the outer leaves also gives the advantage of briefly delaying bolting. In spring, when plants are about to bolt, pull the entire plant at once to enjoy the leaves before they become bitter.
Pests that enjoy spinach include flea beetles, spider mites, and aphids, which feed on the leaves. Diseases that attack plants are downy mildew (a mildew that may appear during cool, moist weather) and white rust (which causes white spots on the leaves).