Potatoes: Solanum tuberosum

By Nina Berryman

The potato is a member of the Solanaceae family, which also includes tomatoes and eggplants. They originated in the mountains of Peru, where indigenous farmers grew over 3,000 varieties. Today, Russians eat more potatoes per person than any other nation. Potatoes come in white, yellow, purple, blue and red varieties. The long, skinny varieties are known as “fingerlings” because they resemble fingers. The part of the potato plant which we eat is the tuber. A tuber can either be a swollen stem or a swollen root. In the case of the potato, it is actually an underground, swollen stem. It is considered part of the stem because it produces both roots and shoots. When below ground, these appendages produce more tubers. When above ground and exposed to sunlight, they produce green stems. If you bury the stem, these shoots can change function, and form more tubers. Hence, farmers grow more potatoes by “hilling” them. This process includes burying all but the tip of the above-ground stems under dirt about three different times throughout the growing season. Leaving the tips above ground ensures that the plant can still receive sunlight and photosynthesize. Almost all potatoes are grown from tubers from the year before. Last year’s potatoes can be cut into smaller pieces to maximize the number of plants you can grow. Cutting the potatoes is not necessary. If you do cut them though, just be sure to leave at least one eye on each piece (better to leave three to be safe). These eyes are actually nodes (like nodes on a stem) where shoots will grow. To give your potatoes a head start in the season, you can encourage them to sprout before you plant them in the ground. This is known as “chitting.” Potatoes can be grown from seed, although this is rarely done. Potatoes will produce above-ground seed pods that are small, round and green. Planting potatoes from seed is a good way to ensure your new crop of potatoes will not harbor any disease, unlike tubers which can carry diseases from the year before.

Source: Ashworth, Suzanne. Seed to Seed. Seed Savers Exchange, Inc. Iowa. 2002