These leafy greens were fit for a queen. An American president, too. And, of course, a beloved comic strip character who became a pop-culture spokesman for the stuff.
Popeye serenaded the vegetable in his theme song, belting out, “I’m strong to the finich ‘cause I eats me spinach, I’m Popeye the Sailor Man!” His Depression Era praises led to an uptick of more than 30 percent in U.S. spinach consumption, according to the 2013 Ian Crofton book A Curious History of Food and Drink. Popeye debuted in 1929 and credited spinach with giving him bulging forearms. He gulped the greens straight from the can, sometimes even right from the garden. A July 3, 1932, comic strip pictures Popeye on his knees, eating just-picked spinach with his bare hands while announcing, “Spinach is full of vitamin ‘A’ and that’s what makes hoomans strong an’ helty.”
Popeye was right: Spinach, low in calories, is rich in beta-carotene, which our bodies convert to vitamin A. One serving of raw spinach, 100 grams, provides more than half of the recommended daily allowance. vitamin A, in turn, helps support vision, the immune system, cell growth, and healthy skin and bones.
Spinach is also a super source of vitamin K as well as a good source of manganese and folate. Most of the iron in spinach, however, isn’t absorbed by the human body. Pairing spinach with foods high in vitamin C—freshly squeezed lemon juice, strawberries, broccoli, bell peppers—helps our bodies access non-heme, or plant-based, iron. Cooking could also help. According to the U.S. Department of Agriculture, 100 grams of raw spinach contains 2.71 milligrams of iron while 100 grams of boiled spinach has 3.57 milligrams.
Spokane dietician Lisa (Baker) Grentz (’96 Food Sci., ’01 MA Nutr.) recommends using spinach within three to five days. Spinach begins to lose nutrients as soon as it’s harvested. When shopping for spinach, Grentz suggests looking for fresh, crisp, green bunches. “Spinach is a versatile vegetable that can boost the nutritional value of many meals and snacks,” she says. “These leafy greens can be added to salads, sandwiches or wraps, paired with eggs, or blended into a smoothie. Cooked spinach can be added to soups, casseroles, pasta or pizza sauces, and much more.”
Sometimes, those dishes are named for a queen. Legend has it Catherine de Medici, queen of France from 1547 to 1559, so loved spinach that she had to have it at every meal. Dishes that incorporated the vegetable were said to be served à la Florentine, recognizing her and the city from which she hailed. She was Italian, a noblewoman from a rich and powerful banking family in Florence. To this day, Florentine-style dishes—eggs Florentine and chicken Florentine are among the most common—inevitably contain spinach.
Young leaves, or baby spinach, are tender, have a hint of herbaceous sweetness and are great for salads. Older leaves offer a bit more of an earthy—even a bit bitter—flavor and are better used in cooking. But their nutritional properties, Grentz says, are best retained when eaten raw or quickly cooked, such as sautéing, stir-frying, or blanching. She particularly likes them as a “nice, neutral base” for salads. “In the summer, I like to add fresh berries and toasted almonds, and toss with a sweet vinaigrette. In the winter, I like to dice up beets and green apples, add some gorgonzola cheese, and toss with a garlic and red wine vinaigrette.”
Spinacia oleracea is a quick-growing crop that prefers cool weather and sandy soil (so be sure to rinse it thoroughly). A member of the beet family, it’s closely related to chard. There are flat leaf, savoy or curly leaf, and hybrid, semi-savoy varieties. Ancient strains were cultivated in Persia as early as 2,000 years ago. By the fourteenth century, it had appeared in France and England, where it was referred to as “spynoches” or “spinnedge.”
Spinach was first listed in American seed catalogues in the early nineteenth century. Thomas Jefferson grew some in his garden at Monticello in 1809 and 1812 for both spring and fall harvests. In 2009, when a portion of the White House garden was planted in honor of America’s third president, the patch included prickly-seeded spinach.
Today, California is America’s top spinach-producing state. It’s one of five— together with Arizona, New Jersey, Texas, and Florida— that grow nearly all of the commercial fresh-market spinach in the country. However, Washington state—specifically, Skagit, Snohomish, and Whatcom Counties—along with the Willamette Valley in Oregon grow about 90 percent of the U.S. spinach seed crop, or about 20 percent of the world’s spinach seeds, according to WSU plant pathologist Lindsey du Toit. She’s been leading WSU’s spinach seed crop pathology research for nearly 19 years. “If you want to grow spinach seed you have to make it flower,” she says. “There’s no other part of the country that has the right conditions.”
Because of their long summer days and dry, mild climate, small swaths of western Washington and Oregon are the only spots in the United States well-suited for cultivating spinach seeds. But the fungus Fusarium oxysporum thrives in the regions’ acidic soils, too. It enters spinach through its roots and grows inside the plant’s vascular system, preventing water and nutrients from reaching the leaves and causing the plant to wither and die.
“It basically clogs up the tissue that should be moving water and nutrients,” du Toit says. “Initially, it’s limited how much clogging there is. Eventually, the tissue becomes completely blocked and the plant succumbs.”
She and a postdoctoral researcher in her program, Sanjaya Gyawali, are searching for spinach varieties that naturally resist Fusarium wilt. Her greenhouse at WSU’s Mount Vernon Northwestern Washington Research and Extension Center grows more than 800 types of spinach, including ancient wild strains from Iran, where spinach is believed to have originated. They’re finding those ancient strains, along with Asian varieties, seem to be the most naturally resistant to the pathogen.
du Toit not only studies spinach but enjoys it, too. “I like the taste of spinach,” she says. “I think it’s a good vegetable. My favorite way to eat it is with cranberries, walnuts, an Italian-type dressing, and grated cheese. I’ve seen it with tangerine pieces, too. It’s refreshing.”
Grentz—like Popeye—endorses spinach consumption for adults and children alike. “Adults are inclined to eat vegetables because of their nutritional and health benefits,” she says. But, sometimes, getting kids to consume leafy greens can be difficult. “One fun way pique their interest is to blend fresh spinach with orange juice. This turns the juice a lime green color, and you can make up a fun name for it like ‘Slime Drink’ or ‘Ninja Turtle Juice.’ Of course, you can always blend in some yogurt and fruits to make a smoothie, if that is more appealing. It’s all about making foods fun, no matter what age you are.”
Lindsey du Toit’s spinach presentation at the International Spinach Conference in Murcia, Spain, in 2018 (PDF)
Spinach information from Skagit County Extension with an additional recipe -2017 (PDF)
Guide to home vegetable gardening in Washington state from WSU Extension – 2013 (PDF)