26 MASSACHUSETTS HORTICULTURAL SOCIETY. 



MEETING FOR DISCUSSION. 



The following Essay, for which a prize had been awarded, was 

 read b}^ the writer, William D. Philbrick, of Newton Centre, 



Mass. : 



Bottom Heat — Its Benefits and Methods. 



B^- the term " bottom heat," as used by gardeners, is described 

 the application of artificial heat, of whatever kind, to the soil in 

 which plants are grown, or in which seeds or cuttings are started 

 into growth under glass, in the autumn, winter, or spring. It is 

 called bottom heat to distinguish it from the heat of the air over 

 the soil, which is maintained, in general, at a lower temperature 

 than that of the soil. The temperature of the air is subject to 

 considerable variation, incident to the effect of sunlight or of 

 cold winds upon the glass, while bottom heat, or the heat of the 

 soil, should be kept more uniform. 



It is very difficult, during the severe weather of our winter and 

 early spring, to start into growth tender and tropical seeds and 

 cuttings, without the application of bottom heat. The earth 

 must be maintained for weeks together at a temperature never less 

 than 60°, even during the long, wind}' nights, when the thermometer 

 outside ma}' indicate several degrees below zero. If heat is applied 

 by artificial methods only to the air over the bed, it is not found so 

 easy to prevent the bed from becoming chilled by the cold earth 

 underneath, which at this season of the year has a temperature of 

 not far from 40°. 



The benefits to be derived from the use of bottom heat, are 

 limited almost wholly to the kinds of work mentioned above, and 

 will be found to be less and less apparent in proportion to the 

 hardiness of the plants or seeds with which we have to deal, and 

 to be less and less needed as the warm weather advances. 



Thus the gardener finds bottom heat essential in starting the 

 seeds of early tomatoes, peppers, egg plants, cucumbers, and 

 melons, and in rooting cuttings of coleus, fuchsia, heliotrope, ver- 

 bena, and other tender plants in early spring ; while the hardier 

 lettuce and radish seeds, and cuttings of geraniums will grow more 

 healthily without bottom heat as soon as the severe weather is past. 

 Cuttings of all kinds are rooted in cool weather much more rapidly 

 by means of it than is possible in any other manner. 



