Extension Educator, Horticulture
My early years were spent watching Popeye cartoons. To produce his super strength Popeye would stuff his face with spinach. I'm sure no kid came up with that idea. As a kid my only experience with spinach was staring down at a green slimy glob that stared back at me with an eyeball of sliced egg. I didn't want to look at it, let alone eat it.
Now I know there are many more tasty and less scary ways to serve spinach, fresh or cooked. I'm not sure about yielding super strength, but I know spinach is as an excellent source of Vitamin A, iron, calcium, and protein.
As I gardener I also love spinach because it is so easy to grow with few insects and diseases. Plus spinach is often the first and last crop of the season. Spinach loves cool weather. Leaves quickly deteriorate during the long hot days of summer.
Spinach is available as smooth leaf or savoy (crinkle) leaf. Many people prefer the smooth leaf varieties for home gardens. The savoy leaf varieties tend to catch soil during rainfalls and can sometimes feel gritty when chewed. If you do grow the savoy, just spend a little extra time washing the leaves.
Popular varieties include:
Plain-Leaf: Giant Nobel (43 days; large, smooth leaves; slow to bolt).
Plain-Leaf Hybrid: Olympia (46 days; slow to bolt; spring, summer harvest).
Crinkled-Leaf: Bloomsdale Long Standing (48 days to harvest; thick, very crinkly, glossy dark green leaves); Winter Bloomsdale (45 days, slow to bolt, cold tolerant, good for over-wintering).
Hybrid Savoy: Indian Summer (39 days; semi-savoyed); Melody (42 days; lightly crinkled; good spring or fall);Tyee (39 days; dark green; heavily savoyed; spring, fall or winter); Vienna (40 days; very savoyed; medium to long-standing).
Spinach can be planted as soon as the soil can be prepared in the spring. If soil was prepared in the fall or soil is too wet to work, seeds can be broadcast then covered with drier soil or potting soil. Plant successive crops for several weeks after the initial sowing to keep the harvest going until hot weather. Seed spinach again in late summer for fall and early winter harvest. Chill seeds for summer or fall plantings in the refrigerator for 1or 2 weeks before planting. Spinach can also be grown in hotbeds, sunrooms or protected cold frames for winter salads.
Sow 12 to 15 seeds per foot of row. Cover 1/2 inch deep. When the plants are one inch tall, thin to 2 to 4 inches apart. The young leaves are tasty in salads. Closer spacing (no thinning) is satisfactory when the entire plants are to be harvested. The rows may be as close as 12 inches apart, depending upon the method used for controlling weeds. In beds, plants may be thinned to stand 4 to 6 inches apart in all directions.
Spinach grows best with ample moisture and a fertile, well-drained soil. Unless growth is slow or plants are light green, supplemental fertilizer is not needed.
The plants may be harvested whenever the leaves are large enough to use (a rosette of at least five or six leaves). Spinach is of best quality if cut while young. Some gardeners prefer to pick the outer leaves when they are 3 inches long and allow the younger leaves to develop for later harvest. Harvest the remaining crop when seedstalk formation (bolting) begins since leaves will quickly deteriorate.
Although spinach seldom has insect or disease problems, slugs can sometimes be pesky. Downy mildew and other fungal leaf diseases may be a problem in wet years with a thick planting. Resistant varieties are available.
For more information on vegetables: UI publication Vegetable Gardening in the Midwest available through UI publications https://pubsplus.uiuc.edu or 1-800-345-6087 or check out our website http://www.urbanext.uiuc.edu/veggies