PRINCIPLES OF PLANTING AND CULTIVATION 43 



which are transplanted for field purposes are grown in cold frames 

 or hotbeds, the seed being sown early in February or March and 

 the young plants placed in the open after the soil has become 

 thoroughly warmed and in a high state of cultivation. 



Beets are less extensively transplanted than the two crops just 

 mentioned, but in some localities they are sown in cold frames in 

 the fall, to be planted in the field early in February or March. 



The sweet-potato plant is less resistant to cold than the cabbage, 

 onion, or beet and is grown, not from ordinary seed, as these 

 plants are, but from the roots which have been held through the 

 winter in suitable storage buildings. In the Northern states these 

 roots are started in manure or fire-heated hotbeds in order to force 

 them into growth for planting in May of the succeeding year. At 

 the South this crop is handled in a different manner. It is sufficient 

 in certain localities to leave a part of the last year's field undis- 

 turbed, so that, the roots will throw up plants for the succeeding 

 year. After these plants have developed to some extent, the young 

 shoots are detached and used as cuttings to add to the plantation. 

 With the long season at the South this method is perfectly feasible 

 and makes the production of this staple crop cheap and satisfactory. 



This illustrates the influence which locality has upon the methods 

 followed in propagating plants which of necessity must be multiplied 

 artificially. 



Making a fire-heated hotbed. A fire-heated hotbed, such as is 

 used at the North for the propagation of sweet-potato plants, may 

 be made somewhat as follows : Select a sloping piece of land 

 which is well protected from the cold winds of February, March, 

 and April, with a southern exposure if possible. The genef.al slope 

 of the land should be such as to allow building a furnace suffi- 

 ciently large to receive 4-foot wood without sawing or cutting. 

 From this furnace carry a brick or sewer-pipe flue through a por- 

 tion of the area which will form the chamber beneath the floor of 

 the hotbed. Arrange supports for the floor high enough above the 

 furnace to prevent the floor' from catching fire, and brick or board 

 up the sides so as to make a tight compartment. Carry the flue 

 to such a distance that no sparks from the fire will be thrown out 

 into the space beneath the floor and so that the smoke will be 

 dissipated throughout the whole compartment. At the end of the 



