CUT-FLOWER CROPS 271 



connected with the house furnace may enter this through 

 the underpinning of the house. The soil is prepared the 

 same as for greenhouse culture, and the plants grown in 

 the frame through the summer and fall. As soon as cold 

 nights come, the sashes are put on the frame and heat fur- 

 nished from the furnace. The heat must not be too intense 

 or the plants will be smothered. The sashes should be re- 

 moved every bright day, and no artificial heat given. 

 Days when the temperature fails to go above 35, the 

 sashes should not be removed. On other days, ventilation 

 should be given as soon as the atmosphere has warmed 

 sufficiently. 



Snow should be kept clear from the sashes, and if a 

 strong, vigorous growth is in every way encouraged, violets 

 may be had in flower during the greater part of the year. 



South of New York City, violets are successfully grown 

 in frames by using decomposing stable manure as a medium 

 of heat. The frames are constructed the same as those 

 described in Chapter IV and a second frame is placed about 

 one foot outside of the original frame. This space is filled 

 with decaying stable manure and firmly compacted. It 

 should generate heat enough to prevent the plants from 

 freezing. Mats and shutters should be provided and the 

 frames covered every cold night. The same directions 

 for ventilation should be followed as those given for the 

 frame heated from the furnace. 



355. Frame culture without heat (Fig. 28) . Violets 

 may be grown in frames without artificial heat. They 

 will not flower to any extent during the winter months, 

 but remain dormant, and flower early in the spring, pro- 

 ducing a crop for the florist, after the violets in the green- 

 houses are through blooming. The plants are placed in 

 the frames in the early fall, and the ground allowed to 



