190 PRACTICAL FLORICULTURE. 



demands, a season of rest in winter ; this being in part 

 denied them, the plants are weakened in vitality and 

 consequently become more or less a prey to disease. To 

 avert that as much as possible, cuttings should be taken 

 from the runners of the Violets in October, rooted and 

 kept in cold frames over winter, which gives them the 

 necessary season of rest, and planted out at one foot apart 

 each way as soon as the ground is dry enough to work 

 in spring, by midsummer they will have started to grow 

 freely ; from that time until the middle of September be 

 careful that all runners are pinched off, so that the whole 

 force of the root can be used to form the crowns for 

 flowering, exactly as Strawberry runners are pinched off 

 to produce fruit. The plants thus prepared for flowering 

 about the end of September are dug up with balls and 

 potted in seven or eight-inch pots, or planted in five or 

 six inches of soil in the benches of the greenhouse at a 

 foot apart. Shade and water for a few days until they 

 have made young roots, after which give all the ventila- 

 tion possible until November. By this time fire heat may 

 be required, but be careful never to let the temperature 

 get over fifty degrees at night. As the plants start to 

 grow, all yellow leaves and weeds should be removed. 



The greenhouses used for forcing Violets have usually 

 been the narrow eleven foot houses, but I am convinced 

 that the rose house structure (page 158) would answer 

 better, as the greatest amount of light in winter is indis- 

 pensable for all flowering plants. Care, however, must 

 be taken that the heating apparatus is so arranged as to 

 secure the necessary low night temperature. Thus, when 

 eight runs of four-inch hot-water pipes are necessary for 

 the rose-house twenty feet wide, six runs will be ample 

 for such plants as Violets, Carnations, Primulas, Stevias, 

 Azaleas, Camellias, or Mignonette ; when a ten or eleven- 

 foot greenhouse is used, three runs of pipes will usually 

 be found sufficient in the latitude of New York, to give 



