The crops of culinary vegetables are of two kinds, those that are permanent, and those that are temporary. Of the _permanent crops_, the most important are the _asparagus_ beds, on account of the great length of time they take in preparing. The ground must be first trenched three or four feet deep, and plenty of stable dung buried at the bottom of the trench. The beds are then marked out four feet wide, and paths left between them; and the plants, which must be procured from a nurseryman (as they should be two years old when they are first put into the bed), must be planted in rows nine inches apart, and deep enough to have the crown of the root two inches below the surface of the ground. The beds are covered with rotten manure during winter, which is forked into the ground in the spring. The asparagus stalks are not cut till the second or third year after planting; but after that the beds continue to produce for twelve or fourteen years, or even more. All the shoots that push up from April to Midsummer may be cut off and used for the table; but those that spring after Midsummer should be suffered to expand their leaves, in order that they may elaborate their sap, and thus strengthen the roots. _Sea-kale_ is planted in beds in the same manner as asparagus, when the plants are a year old. The first year the plants will require little care, except cutting down their flower stems whenever they appear; but the second year, each plant must be covered with river-sand, and then have a sea-kale pot turned over it, on which must be heaped stable dung fifteen or twenty inches high, in order that the heat may make the young shoots grow rapidly, and thus make them tender and succulent. _Artichokes, tart-rhubarb_, and _horseradish_, are other permanent crops found in kitchen-gardens, but they do not require any particular care in their culture. The _temporary crops_ in kitchen-gardens require a constant change, as it is found from experience that the same crop cannot be grown on the same ground for two years in succession, without becoming of an inferior quality; and thus it is found necessary to fix what is called the rotation of crops, and to arrange that in each compartment a fresh crop shall be grown every year, as different as possible from the one that grew in it the year before. Thus, onions may be succeeded by lettuces, carrots by peas, potatoes by cabbages, and turnips by spinach. These plants may of course be varied according to circumstances; but the principle is never to have two fleshy-rooted plants like the carrot and the potato succeed each other; but always to let a plant cultivated for its leaves or seeds follow one cultivated for its root, and so on.