This section is from the book "A Dictionary Of Modern Gardening", by George William Johnson, David Landreth. Also available from Amazon: The Winter Harvest Handbook: Year Round Vegetable Production Using Deep Organic Techniques and Unheated Greenhouses.
Twenty-eight species, of which the most important is the kitchen vegetable, asparagus officinalis. Of this there are only two varieties, the purple topped and the green-topped; the first is principally cultivated. There are a few sub-varieties which derive their names from the places of their growth, and are only to be distinguished for superior size or flavour, which they usually lose on removal from their native place.
The soil best suited to this vegetable is a fresh sandy loam, made rich by the abundant addition of manure.
The site of the beds should be such as to enjoy the influence of the sun during the whole of the day, as free as possible from the influence of trees and shrubs, and if choice is allowed, ranging east and west. The subsoil should be dry, or the bed kept so by being founded on rubbish or other material to serve as a drain. The space of ground required to be planted with this vegetable for the supply of a small family is at least eight rods. If less it will be incapable of affording one hundred heads at a time. Sixteen rods will in general afford two or three hundred every day, in the height of the season.
To raise plants, the seed may be sown from the middle of February to the beginning of April; the most usual time is about the middle of March. The best mode is to insert them by the dibble five or six inches apart, and an inch below the surface, two seeds to be put in each hole, or they may be sown in drills made the same distance asunder.
If dry weather, the bed should be refreshed with moderate but frequent waterings, and if sown as late as April, shade is required by means of a little haulm during the meridian of hot days, until the seeds germinate. Care must be taken to keep them free from weeds, though this operation should never commence until the plants are well above ground, which will be in the course of three or four weeks from the time of sowing. If two plants have arisen from the same hole, the weakest must be removed as soon as that point can be well determined. Towards the end of October, as soon as the stems are completely withered, they must be cut down, and well putrefied, dung spread over the bed to the depth of about two inches; this serves not only to increase the vigour of the plants in the following year, but to preserve them during the winter from injury by the frost. About March in the next year, every other plant must be taken up and transplanted into a bed, twelve inches apart, if it is intended that they should attain another, or two years' further growth, before being finally planted out, or they may be planted immediately into the beds for production.
It may be here remarked that the plants may remain one or two years in the seed bed; they will even succeed after remaining three, but if they continue four they generally fail. It is, however, certain that they are best removed when one year old.
Some gardeners judiciously sow the seed in the beds where they are to remain for production.