I’ve never had any trouble believing that spinach made Popeye strong. Imagine what powers he might have had if it he’d eaten garden spinach instead of canned.
A well grown spinach patch is beautiful: rows of lush, dark green leaves waiting to be picked and tossed in a hearty salad, or sautéed just long enough to wilt in a little olive oil and garlic. Spinach is the most versatile of greens, a main course vegetable with mainstream popularity.
No one is sure what the original spinach looked like, but it’s fairly modern as food crops go. Spreading from Central Asia to Arabia, from whence the Moors introduced it to Spain, it reached England in the Middle Ages, possibly via the Crusades. It appears as “spynoches” in a 1390 cookbook written for Richard the Lionheart and his court. Perhaps that’s what made him lionhearted.
As spinach proceeded to conquer the world, its name came to identify many other greens not related to the true spinach (Spinacia oleracea) and often much older. There’s Chinese spinach and African spinach (both are amaranths), Malabar spinach (Basella rubra), New Zealand spinach (Tetragonia tetragonioides), Cuban spinach (miner’s lettuce), Australian spinach (lamb’s quarters), French spinach (red goosefoot), Southern European spinach (a chardlike plant), wild spinach (Good King Henry), mountain spinach (orach), vine spinach (Basella alba) and water spinach (Ipomoea aquatica).
Spinach certainly is a nutritious vegetable, rich in iron, calcium, potassium, magnesium, vitamins A and C, and a surprising amount of protein. Recent attention has been paid to its high levels of folate (essential for pregnant women) and heart-protecting carotene (its orange color masked by all that chlorophyll green).
Somewhat more controversially, spinach is said to contain high levels of oxalic acid, an intestinal irritant that also binds up calcium, making it less available to the body, and under certain conditions dangerously high levels of nitrates as well. But both these problems may be more a function of how spinach is sometimes grown. It is not difficult to produce nutritious spinach, once you know what conditions it prefers.
Spinach needs cool weather. If sown in the low temperatures and fairly short days of spring, followed by warm weather and lengthening days, it will bolt —that is, follow its natural inclination to send up a flower stalk. With modern bolt-resistant varieties there is time to get in a quick crop in springtime if you start early enough
But fall will often yield the best spinach. The key is to wait until cool weather will soon start to settle in, but there are still enough frost free days to bring the crop to maturity. At our farm we sow outdoor spinach on Aug. 18. Many spinach varieties are hardy to 15 degrees F and can be harvested all winter long, especially if protected with something easy to remove such as straw, evergreen boughs, or floating row covers. Keep picking the outer leaves, and new ones will continue to grow at the center.
Since bolting is not a problem for crops grown in shortening days and cool weather, you should look for fast-growing, cold-hardy varieties instead of “long-standing” ones. We’ve had good luck with ‘Space’ from Johnny’s Selected Seeds.
Another trick is to sow a late crop that will germinate just before the ground freezes up, then overwinter. For this you’ll want a hardy but bolt-resistant variety such as ‘Tyee’ since it’ll do its growing in springtime. In Maine you’ll need a cold frame or greenhouse for this.
Good drainage is essential, so if your soil is soggy use raised or mounded beds. Sow seeds ¼- to ½-inch deep in rows as close as 8 inches apart, then thin to a 4-inch spacing in the row, eating the discards in salads.
As for fertility, the key is balance. Though spinach is a nitrogen-loving plant, it is heavy applications of nitrate fertilizers that lead to not only the nitrates problem but the oxalic acid problem as well. The use of balanced organic, slow-release fertilizers or — better yet — well-aged manures and composts, will ensure a healthful crop. If your soil is acid and low in calcium, be sure to add some limestone.
What’s in the future for this excellent plant? Just the continuing, careful work of excellent breeders, one hopes, and not the horrific fate reported by the BBC on Jan. 24, 2002. Scientists in Japan had successfully produced two generations of leaner pigs by inserting a spinach gene into a fertilized pig egg.
In my opinion this is an insult to the noble pig, whose flesh is leaner and healthier when it leads something more like the athletic life it was designed to lead in nature, foraging for acorns in the woods, not gorging on corn in a pen.
It is also an insult to you, an intelligent animal quite capable of eating, if need be, a smaller slice of pork. Or a bigger plate of spinach.