626 RAD1CACEOUS ESCULENTS. 



contrary, four inches is too shallow, occasioning the tubers to be 

 partially exposed to the light, and hence to become green. If, however, 

 the land is so shallow as to admit of no greater depth, then more 

 space must be allowed between the rows for earthing up. " In one of 

 the experiments above alluded to, different depths were also inquired 

 into, when the rates of produce were nearly as follows : Three inches 

 deep gave 13 tons ; four inches, 14 tons; six inches, 14^ tons ; and 

 nine inches, 13 tons. At so great a depth as nine inches, sets are apt 

 to perish, unless the soil is dry, light, and warm. The deeper, however, 

 the sets can be safely inserted, the better, for the following reason : 

 Potatoes are formed on underground branches ; the deeper the set, 

 the more branches will be formed before the shoots emerge from 

 the soil, and consequently the more ample will be the means possessed 

 by the potato plant of forming tubers. The important practice of 

 earthing-up is to effect the same end, by compelling the potato stem 

 to grow as much as possible underground. 



" The best method of increasing a crop of potatoes is to destroy all 

 the flowers as they appear. The flowers and fruit of plants are formed 

 at the expense of the secretions elaborated by the leaves ; if of those 

 secretions a part is consumed in the organization of flowers and fruit, 

 there is so much the less to accumulate in the tubers ; but if no such 

 consumption is permitted, the tubers will become the depositories of 

 all the nutritious matter which the plant is capable of producing." 

 ('Gard. Chron.,' 1842, p. 155.) 



For an Early Crop. The sets may be planted in the first week of 

 October, in a sheltered dry situation, in light sandy soil, eight inches 

 or nine inches deep, and the surface of the ground afterwards covered 

 with long dry litter in such a manner as to exclude the frost and throw 

 off rain. To facilitate the latter object, the sets are best planted in 

 beds, the rain being conducted by the litter to the alleys ; or three 

 rows may be planted at a foot apart, leaving every third interval of 

 the width of twelve feet. The plants will appear above ground in March, 

 and with the usual routine culture, and nightly protection till all 

 danger from frost is over, they will produce potatoes fit to gather in 

 May, or early in June. A better mode is to forward the sets by laying 

 them on dry straw in a warm loft, room, or cellar, or on the floor of 

 a greenhouse in January, or the beginning of February ; and when 

 they have produced shoots of two inches or three inches in length, 

 which will be the case about the middle or end of March, to plant 

 them out in dry, warm, sheltered soil, covering them with litter at 

 night, and exposing them to the sun during the day. Both these 

 modes are practised in Lancashire and Cheshire, and by both young 

 potatoes are brought to market by the first week of June, and some- 

 times earlier. By using whole potatoes as sets, burning out with a 

 red-hot iron all the eyes except one, the abundant nutriment thus 

 supplied increases the rapidity of the growth of the young shoots, and 

 produces both an abundant and an early crop. Planting either sets, 

 or sprouted sets, at the base of a south wall, and giving nightly pro- 

 tection, win produce potatoes fit to gather about the end of May ; and 



