355. The forcing of asparagus was practised in Eng• land in the middle of the 17th century. Meager mentions, that the London market was, at that period, supplied with forced asparagus early in the year : " Some having old beds of asparagus which they arc minded to destroy, and having convenience of new or warm dung, lay their old plants in order on the dung. and the heat cloth force for wardt farewell crop," (p. 188.) The forcing of this arti cle is now carried to a considerable extent in the neigh bourhood of London. It is likewise very generally prac tised in private gardens.
A common hot-bed, prepared with horse dung, is form ed according to the size of the frame or frames. A layer of turfs is sometimes placed on the dung, to prevent the access of the vapour from it, which is apt to hurt the fla vour of the crop. About four inches of good light soil or old tan-bark are placed on the turf. In this plants six or eight years old are closely deposited. These plants are sometimes got from nurserymen, to whom such stock is no longer useful ; or one of the oldest beds in the garden is for this purpose sacrificed, care being taken to have succes sion beds coming forward. But where the demand for the market, or for a private family, is regular, the best way is to have several successive beds in progress. Those plants intended for forcing may be transplanted as usual when one year old, but in much closer order, and so kept till the fourth year. A three-light garden frame will hold from 600 to 800 three-year-old plants. The roots are placed as close together as possible (as already hinted,) with the buds standing upright, and covered with three or four inches of soil. The temperature of the dung is gene rally regulated merely by guessing the heat imparted to sticks plunged into it if it becomes too weak, a lining of weeds or dung is heaped around the sides: if it prove too strong, some air holes are formed, by pushing large sticks into the sides and withdrawing them, leaving empty spaces, or by removing the glass covers for some time. The pro per temperature is about Fahrenheit. Air is occasion ally admitted, by raising the glasses a little ; and some times a slight watering is necessary. At other times, in severe weather, mats are laid over the frames. A little fine light earth is sometimes added, once or twice, as the buds rise. In five or six weeks some of the shoots are generally fit for gathering. In France they often cut in a fortnight ; but shoots produced in this rapid way are in a great measure colourless and tasteless, having been forced nearly without access of light and air. In gathering the
shoots from a hot-bed, it is thought better to avoid cutting with a knife, and to employ only the finger and thumb ; by a gentle twist the shoot is detached, and with less risk of injuring the tender buds below. Each light or frame yields on an average 300 shoots, which come in succession during about three weeks. Where a regular winter sup ply of this article is desired, beds are made up in succession accordingly, from November toiMarch. After being forced, the plants are cast on the dunghill as useless.
NI! Nicol describes a mode of forcing asparagus in flued pits, such as are used for young pine-apple plants. A layer of old half rotten hark, placed over well fermented dung, forms the bed, the plants being placed in light dry earth. Very little fire-heat is found to be necessary; generally a slight fire at night is sufficient. Watering, and the regu lar admission of air, are to be attended to. He remarks, that by means of very simple expedients, one half of a flued pit may be forced, and the other kept back, and•thus a•suc cession of shoots secured.
356. Asparagus, it may be remarked, was a favourite of the Romans ; and they seem to have possessed a very strong growing variety, as Pliny mentions that, about Ra venna, three shoots would weigh ft pound ; with us, six of the largest %vould be required. It is much praised by Cato ; and as he Amlarges on the mode of culture, it seems probable that the plant had but newly come into use. In this country, Dutch asparagus was preferred in the end of the 17th century ; and this vat iety is still distinguished fot afferding the thickest shoots. In a garden formed at Dun bar in the very beginning of the 18th centuty, b) Pitovost Fall, (a name well known in the mercantile world,) aspara gus was for many years cultivated with uncommon success. The variety used was the red topped, and it was brought from Holland. The soil of the garden is little better than sea sand. This was trenched two feet deep, and a this k layer of sea-weed was put in the bottom of the trench, and well pressed together and beat down. This was the only manure used either at the first planting, or at subsequent dressings. There was an inexhaustible supply of the arti cle generally at hand, as the back-door of the garden opens to the sea-shore.