Use.—The roots were formerly much esteemed, but are now neglected for those greatly inferior. When cooked and served as salsify or scorzonera, they are the whitest and sweetest of esculent roots, and afford a considerable portion of nourishment.
SWEET POTATO.
Spanish Potato. Carolina Potato. Convolvulus batatus. Ipomœa batatas.
The Sweet Potato is indigenous to both the East and West Indies. Where its growth is natural, the plant is perennial; but, in cultivation, it is always treated as an annual. The stem is running or climbing, round and slender; the leaves are heart-shaped and smooth, with irregular, angular lobes; the flowers, which are produced in small groups of three or four, are large, bell-shaped, and of a violet or purple color; the seeds are black, triangular, and retain their vitality two or three years,—twenty-three hundred are contained in an ounce.
The plants rarely blossom in the Northern or Middle States, and the perfect ripening of the seeds is of still more rare occurrence. The latter are, however, never employed in ordinary culture; and are sown only for the production of new varieties, as is sometimes practised with the common potato.
Soil, Planting, and Cultivation.—In warm climates, the Sweet Potato is cultivated in much the same manner as the common potato is treated at the North. It succeeds best in light, warm, mellow soil, which should be deeply stirred and well enriched. The slips, or sprouts, may be set on ridges four feet apart, and fifteen inches from plant to plant; or in hills four or five feet apart in each direction, three plants being allowed to a hill. During the summer, give the vines ordinary culture; and late in September, or early in October, the tubers will have attained their growth, and be ready for harvesting. The slips, or sprouts, are generally obtained by setting the tubers in a hot-bed in March or April, and breaking off or separating the sprouts from the tubers as fast as they reach four or five inches in height or attain a suitable size for transplanting. In favorable seasons, the plucking may be repeated three or four times. In setting out the slips, the lower part should be sunk from one-third to one-half the entire length; and, if very dry weather occurs, water should be moderately applied.
Keeping.—The essentials for the preservation of Sweet Potatoes are dryness and a warm and even temperature. Where these conditions are not supplied, the tubers speedily decay. By packing in dry sand, and storing in a warm, dry room, they are sometimes preserved in the Northern States until the time of starting the plants in spring.
Varieties.—Though numerous other varieties, less marked and distinctive, are described by different authors, and are catalogued by gardeners and seedsmen, the principal are as follow:—