Nurturing nutrition: throwing spinach into the mix benefits body and soil

Flower & Garden Magazine, Sept-Oct, 1998 by Jennifer Curry

Throwing spinach into the mix benefits body and soil.

Popeye knew what he was talking about. Spinach (Spinacia oleracea) is one of the most nutritious vegetables you can grow in your garden. It is an excellent source of iron, folic acid, and it is high in vitamins A and C. Spinach is most nutritious served raw, though it has become a staple in casseroles, quiches and souffles.

Not only is spinach good for the body, it's good for the garden. Spinach produces exudates that stimulates growth in other vegetables, such as cabbage. It also helps maintain soil moisture and microorganisms.

SELECTING A VARIETY FOR YOUR GARDEN

Spinach is particularly well-suited to small gardens as the plant takes up little space and provides a large edible yield. Since spinach grows in either full sun or partial shade, it works well as a filler when planted between rows of taller plants.

There are two main types of spinach: savoy and smooth leaf. Savoy is most popular because its crinkly leaves are considered more attractive, though they are more difficult to clean.

Different varieties of spinach have differing maturation times and tendencies towards bolting. `Bloomsdale Longstanding' is a sturdy old savoy that thrives in most regions. Though its bolt-resistant nature makes it an excellent choice for spring, it can withstand cold temperatures as well. `Bloomsdale Longstanding' has a long growth period and is a good choice for over-wintering. The `Razzle dazzle' hybrid has the shortest maturation time of any other spinach variety, however it is more likely to bolt. These traits make this hybrid perfect for late fall or early winter harvest, when you are trying to beat the frost instead of the heat. Consult your local nursery about which spinach variety best fits your climate and planting time.

SEASON AND CLIMATE

Although spinach can be planted in the spring, as well as the fall, it's best grown as a cold crop. Spinach germinates quickly when the days are cool and short; temperatures between 60 and 65 degrees Fahrenheit are optimum. Spinach can withstand a low of 20 [degrees] F, though it's growth is depressed under 35 [degrees] F.

The plant will tolerate a high of 77 [degrees] F, but even milder temperatures may increase the risk of bolting. Once a spinach plant has flowered, the leaves will become tough, bitter and unsuitable for your salad.

Gardeners in Zones 7 through 10 can plant spinach as a fall crop and harvest throughout the winter. Starting in September, those in Zone 7 can plant as late as the first of November. Gardeners in Zones 8 through 10 can plant from October through December.

In colder areas you can overwinter spinach if you plant it in September, and mulch well enough to provide adequate insulation for the winter months. By getting a jump-start on the spring growing season, you can extend your spinach harvest.

PLANTING AND CARE

All varieties of spinach share the same basic soil requirements. It's important to check your soil pH before planting. If pH levels are too low, the leaves will turn yellow. If the levels are too high, the plant will be stunted. Select an area with sandy, well-drained soil. Spinach needs a great deal of water, but it is also prone to contracting mildews.

Before planting spinach, prepare the soil by broadcasting a high-nitrate fertilizer, such as fish emulsion. If you are concerned about the nitrate levels in your soil, you may want to only sidedress the plants. The soil should be tilled about 6 inches deep with seeds planted 1/2 inch deep and 1 inch apart. Allow a foot or more of space between rows.

As transplanting disturbs the delicate spinach roots, it's best to direct sow seeds. Soak seeds in lukewarm water a few hours before sowing to aid germination. If you do decide to plant seedlings, start them four to six weeks before planting.

In the garden, thin the seedlings once they reach a height of 1/2 inch. You can thin by hand, but it is easier to use a garden rake with quarter-inch teeth and pull it across the rows. This will thin the rows nicely and eliminate some of the weeds.

Weeds can choke the shallow roots of spinach plants, so it is important to weed consistently. When plants are a few inches high, side-dress with a high-nitrate fertilizer. Water at least 1 inch a week, using a soaker hose to prevent mildew. Spinach is a low-maintenance plant, requiring only these simple steps while maturing.

HARVESTING AND STORING

Spinach usually matures in one to two months. You can begin to harvest after leaves have reached 3 to 5 inches. Avoid harvesting after a heavy rainfall or dew, because the leaves will be brittle and likely to tear or crack. Pick the outer leaves, allowing the inner ones to continue growing. If you prefer, you can harvest the entire plant by cutting an inch above the base. New leaves will sprout from the remaining stems. The leaves look large when harvested, but once cooked, they wilt to a smaller size.

Spinach won't keep long after harvest, however it does freeze well. Blanche leaves by boiling them in water for two minutes before placing them in ice water to chill. Pat off excess liquid with a paper towel before packing into freezer bags. Moisture left on the leaves will breakdown the vitamins and affect the flavor.