Power plant: Spinach

Besides big muscles, Popeye likely had healthy eyes. Research has shown that spinach is one of the richest vegetable sources of lutein, a natural plant pigment that protects the eyes against age-related macular degeneration and cataracts. Nutritionists suggest that six to 12 milligrams of lutein be consumed daily; just one cup of cooked spinach contains 13 milligrams. The high folic acid content of spinach may help prevent heart disease. No wonder Popeye ate his spinach.

Planting and Growing
Spinach (Brassica perviridis) is a cool-weather crop originally grown in fall and winter in the fertile valleys of the Middle East. In North America, it grows best in the shorter days of early spring and fall, since days lasting 14 hours or more trigger spinach to go to seed. Hot weather speeds up the flowering process and makes the leaves tough and dry.

Spinach varieties have three different types of leaves: smooth, savoy (crinkly, curly) and semi-savoy. While some say the smooth leaves are tastier, others prefer savoy. The main advantage of savoy is that it's more winter hardy.

For a spring crop, plant four to six weeks before your last frost. Choose varieties that are slow to bolt. Sow successive crops every two weeks until daytime temperatures rise above 18°C and days begin to lengthen.

Spinach needs a fertile, well-drained soil with a pH of around 6.5. If the soil is too acidic, spinach won't grow properly, and if it's too alkaline, the plants may develop a magnesium deficiency. Prepare the bed by digging in generous amounts of compost or composted manure.

Plant the seeds 2.5 centimetres apart, one centimetre deep, in rows 30 centimetres apart. In heavy clay, cover the seeds with sifted compost to prevent the surface from crusting. Keep the seedbed moist. When the leaves of the seedlings begin to touch, thin them to 7.5 centimetres apart and later to 15 centimetres.

Keep the plants well watered. Mulch with straw, hay or shredded leaves to help conserve moisture and keep the roots cool. Keep the plants well weeded; if using a hoe, just scratch the surface to avoid damaging the roots. Maxi-mize air circulation by not overcrowding.

When the plants are half grown (three to four weeks), feed with compost tea, made by soaking a bag of compost overnight in a pail of water. If they're growing slowly and leaves are pale, feed with additional compost tea or an organic fertilizer. While spinach needs a good supply of nitrogen for heavy yields of dark green leaves, too much nitrogen can result in the production of excess nitrates, which could pose a health risk if too much is ingested.

Once spinach plants have bolted, pull them out and replant the bed with a heat-loving crop such as beans. Don't try to grow spinach in the long, hot days of summer. For fall crops, plant eight weeks before the first hard frost to produce good-sized plants before the days become too cold for further growth. Since spinach doesn't germinate well in soil temperatures above 24°C, you may need to keep the seedbed cool by watering it daily, shading it with a cloth or covering the seeds with a board until they germinate.

HARVESTING & STORAGE
Spinach is ready for harvesting six to eight weeks after planting, depending on the variety and the weather. The colder the weather, the slower the growth. Start picking when there are at least six large leaves on the plant, harvesting the outside leaves before they become too large. As it grows, up to half the plant can be harvested at once. Discard any yellow or wilted leaves. Wrap unwashed leaves in damp paper towels and store in a plastic bag in the refrigerator. Use within three days.