Ipomoea

These perennial or annual climbing plants come from North America, Asia, South Africa and the West Indies and have several common names, one of which is Morning Glory. This group includes the Sweet Potato, I. Batatas. Most of these plants, however, are grown for their pretty flowers. The twining, climbers grow from 10 to 30 feet high and the bushy Morning Glory forms a mound, 3 to 4 feet high. The leaves are green or variegated silvery white, ovate or heart-shaped and up to 6 inches across. The foliage of the Cardinal Climber is finely cut. The flowers are trumpet-shaped and large, 4 to 5 inches across. They may be pink, rose, red, white or blue and are often bicolored with edging, stripes or flecks. They are sometimes fragrant. I. alba, the Moonflower, blooms at night. I. Leari, Blue Dawn Flower, is a perennial with beautiful blue flowers that turn red. I. pandurata, Wild Sweet Potato Vine, produces white flowers with purple throats; it is also a perennial. I. tuberosa, the Wood Rose, is a tropical vine common in Hawaii. It has yellow flowers and the woody sepals of the dried pods form the "wooden roses" valued for decorative purposes.
Sweet Potato - I. Batatas is the botanical name for the Sweet Potato. This vegetable is grown for its edible roots. When cultivated in the U.S., it rarely produces flowers. Sweet Potatoes grow rapidly and form runners and dark green leaves, which are tinted with a purplish-red in some varieties. It is a native of tropical America, which explains why this vegetable thrives where summers are fairly long and warm. Certain kinds of Sweet Potatoes, especially the moist-fleshed ones, are usually called Yams. The use of the word Yam, however, is confusing because it is actually a different plant; Dioscroea to be correct.

Pot Cultivation

Morning Glories will grow in regular soil, which is moist to on the dry side, in a sunny position. Those grown in the greenhouse need to be grown in large pots or tubs or in a prepared bed of soil filled with two parts loam, one part peat moss or leaf mold and one part well-decayed manure, with a liberal amount of sand. They need a minimum winter temperature of 45 degrees. Train the shoots to wires or a trellis attached to the wall or roof of the greenhouse. In early spring, the soil is top dressed with rich compost and straggling shoots are cut off to prevent crowding. From April to May, a lot of water should be given and occasional applications of dilute liquid fertilizer. During the winter, the soil is moistened only when dry.
Sweet Potato - This vegetable grows best in very sandy soil. They won't do well in clay soil or muck. The soil should be plowed or spaded and, if fertilizer is necessary, one low in nitrogen should be used. Too much nitrogen will result in luscious vine growth at the expense of tuber development. Because of this, it is usually better not to fertilize before planting Sweet Potatoes, but rather set them in ground that was fertilized for a previous crop. Sweet Potatoes do not like cool soil, so plant slips (rooted cuttings) in early summer, even later than muskmelons and peppers. If soil is heavy and full of clay, work it up thoroughly into raised beds, 4 feet wide and set slips a foot apart down the center. Spread 5-10-5 fertilizer and mulch deeply around the slips with spoiled hay, rotting straw, or shredded dry leaves. Late in the season, probe beneath the vines to test root size. Let them grow as late as you can, but don't let them be hit by frost. Even a week or two of growth at the end of the season can add 10 percent to the weight of the crop. If an early frost is anticipated, cover the bed temporarily to keep the vines growing through early fall. When you harvest your Sweet Potatoes, take care not to puncture or scrape the roots and don't wash them. Injured or squeaky-clean roots won't store reliably. Cure roots at 85 to 90 degrees for 7 to 10 days in an unused cold frame or a heated room. After that, lay them in a cool, dry, well-ventilated area; keep the roots from touching to prevent rot. Sweet Potatoes make pretty and interesting house plants. Take a mature tuber (one that hasn't been heat treated so much that it won't sprout) and poke three toothpicks or similar slivers of wood around its sides and set it into a glass of water until the toothpicks rest on the rim of the container. It would be smart to add a few pieces of charcoal to the water. The water should always touch the bottom of the tuber and it should be changed once in a while. Keep the jar in a sunny window and it will sprout green, leafy vines, which can be trained to stakes, strings or wire or they may be allowed to hang down. The same results may be achieved by planting the Sweet Potato in a pot of soil and keeping it moist.

Propagation

In the spring, seeds may be sown in pots of sandy soil or cuttings can be inserted in a propagating case; the shoots can be layering in the summer. Seeds may also be sown outside where they are to grow when the soil warms. The seeds should first be soaked for 24 to 48 hours in tepid water.
Sweet Potato - Start slips (rooted cuttings) by sprouting whole tubers in warm, moist potting soil or sand.