By Jill Henderson – Show Me Oz
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Sweet potatoes are an ancient food crop; a staple that has sustained and nourished mankind for thousands of years. Highly nutritious, sweet potatoes are the seventh most important food crop in the world. Throughout the ages these sweet, orange, red and sometimes golden roots were valued so highly by early man, that they were often used as a form currency and as a token of friendship between cultures. Today, this weirdly-shaped “potato” is making a comeback with home gardeners – and for good reason.
To begin at the beginning one must first make note of the fact that sweet potatoes are not Irish potatoes, nor are they yams. Irish potatoes are actually fleshy underground stems (aka: tuberous stems) that belong to the Nightshade (Solanaceae) family of plants. Other garden nightshades include which tomatoes, peppers and eggplant. Yams, on the other, hand are a type of tuberous perennial liana belonging to the Dioscoreaceae family. Yams are by far the most notable member of this family. The tubers of yam are the only edible part and only after they have been cooked. Raw yams contain measurable amounts of saponins, which can be slightly toxic if it is eaten raw in large amounts.
Sweet potatoes (Ipomoea batatus) belong to the Morning Glory (Convolvulaceae) family of plants. Within this family are many genera, of which Ipomoea is but one genus. The Ipomoea genera includes species such as moonflower (I. alba) and cardinal climber (I. multifida). Sweet potatoes and most common morning glories belong to the species batatus. In most gardens, this species is grown as an annual or tender perennial. All batatus have twining vines and large, showy trumpet-shaped flowers and distinctive heart-shaped leaves held aloft by long succulent stems.
With the popularity of ornamental varieties of sweet potato on the market today, there is some confusion as to which sweet potatoes are edible and which are not. Since some members of this family are poisonous, eat only the tuberous roots and leaves of garden-variety sweet potatoes, just to be safe.
And eat it you may, for true sweet potatoes are edible from top to bottom.
The leaves of sweet potatoes are relished in many countries, but especially those with tropical to semi-tropical climates such as Central and South America, India, and other parts of Asia. During my travels throughout southeast Asia, the leaves of Ipomoea were a farmer’s market special. The raw leaves and tender petioles are sweet and crisp and are often served alongside spicy dishes such as curry.
In addition to being eaten raw, the leaves of sweet potato are cooked. In Asia, we found them being lightly stir fried or added as a last-minute green to broth-based soups. You can do the same with the sweet potato leaves from your own garden crop. Try them fresh in salads, pickled, stir fried, or lightly steamed. Pick freshly opened, unblemished leaves and rinse in plain water. Wrap in damp paper toweling until ready to eat.
Although the leaves are edible, sweet potato vines are grown primarily for their swollen underground roots. These tuberous roots act as storage vessels for nutrients and water that the plant will use to survive adverse conditions and for reproduction. Through the storing of dense amounts of nutrients, sweet potatoes become a highly nutritious food for man and animal.
According to the Growing Sweet Potatoes Fact Sheet published by the Maryland Cooperative Extension at the University of Maryland, a medium-sized sweet potato contains the following nutrition: “130 calories, 0 [grams] of fat, 17 mg sodium, 350 mg potassium (10%), 28 grams of total carbohydrate (10%), 3.4 grams of dietary fiber (14%), beta-carotene (about 16 mg), 26 micrograms folate (6.5%), 2 grams of protein, over 500% vitamin A (for both men and women), 47% of vitamin C, 4% calcium, and 3.4% iron (based on a 2,000 calorie dietary requirement).”
That’s pretty impressive for a root crop that’s easy to grow, relatively care-free and beautiful to look at. These roots pack a nutritional punch, taste great, are low in fat and will fill you up every time.
Sweet potatoes are also versatile, lending themselves to just about any preparation method – baked, boiled, steamed or fried and mashed, diced or sliced – sweet potatoes have an uncanny flexibility that will suite even the pickiest eater. The smooth, sweet flesh of sweet potatoes lends itself to many kinds of seasonings and can be found in everything from decadent baked goods to savory fillings, stews and sauces. And don’t forget sweet potato fries! Regardless of how you choose to prepare this wonderful root, it always tastes good!
Besides storing nutrients and tasting good, the tuberous roots of sweet potatoes are also used to start new sweet potato plants. Next week, I’ll continue the sweet potato theme with the article, Start Your Own Sweet Slips. Tune in to learn more about how you can grow this garden delicacy in your own garden and how to start your own sweet potato starts!
Until then, Happy Gardening!