The sweet potato is cultivated generally in all the intertropical regions, for the sake of its roots, and as a legume in temperate countries.  In the Southern States of North America, the culture ceases in Carolina under latitude 36 degs.; in Portugal and Spain it reaches to latitude 40 and 42 deg.; and as a legume its cultivation is attempted to the vicinity of Paris.  In India it is a very common crop; its tubers are very similar to the potato, but have a sweeter taste, whence the common name; but it must not be confounded with the topinambur (Helianthus tuberosus), a native of Brazil, which is less cultivated.  The root contains much saccharine and amylaceous matter.

Several marked varieties of the sweet potato are raised in the Polynesian groups.  In some islands it forms the principal object of cultivation.

It is grown in the Northern districts of New Zealand, at Zanzibar, Monomoisy, Bombay, and other parts of the East Indies.  They are raised on the bare surface of the rock in some parts of the Hawaiian islands, and a sourish liquor is procured from them.  It was early cultivated on the Western Coast of Africa, for the Portuguese Pilot (who set out on his voyages to the colony at St. Thomas, in the Gulf of Guinea) speaks of this plant, and states that it is called “batata” by the aboriginals of St. Domingo.  They are abundant at Mocha and Muscat.  Sweet potatoes form a principal and important crop in the Bermudas.

A valuable addition has lately been made to the votaries of the sweet potato in Alabama, supposed to be from Peru.  A letter describing it says:—­“It is altogether different and equally superior to any variety of this root hitherto known.  It is productive, and attains a prodigious size, even upon the poorest sandy land, and the roots remain without change from the time of taking them out of the ground until the following May.  The plant is singularly easy of cultivation, growing equally well from the slip or vine, the top or vine of the full-grown plant being remarkably small; the inside is as white as snow.  It is dry and mealy, and the saccharine principle contained resembles in delicacy of flavor fine virgin honey.”

There is in general a great error in cultivating this root, as most people still plant in the old way, two or three sets in the hole, which is a great deal too close.

When a piece of land is to be planted in sweet potatoes, it should be top-dressed with some manure, to be dug or ploughed under a week or two before it is to be planted.  Drills should be made two feet apart, and the potatoes placed in the drill about one foot asunder.  From eight to twelve to the pound are the best size for planting.  The “white upright” kind, when intended for sets, should be taken up early in March, and kept about a month, so as to be quite dry before planting.  Abundant crops can rarely be raised from the stem of the “uprights;” the old potato, however, grows to a large size.  I have planted a potato weighing about an ounce, and dug it up in August, weighing over two pounds.  The drills can be made with a small plough to great advantage, when a person understands it.