CONSTRUCTION OF HOTBEDS 
105 
advantage. This may lie secured by natural windbreaks, 
as hills and trees. Buildings may also serve the purpose. 
A common practice is to plant hedges or to construct 
board walls 5 or 6 feet high for this purpose. The walls 
may also be used to support the mats while drying. 
South or southeastern exposures are preferable to 
others. The frames should run parallel with each other, 
with ample space between them for alleys or roadways, 
for the handling of mats and sash, and for snow shoveled 
from the glass. To serve these purposes best there 
should be at least 10 feet between the frames, but when 
the land is high priced and limited in area it is economy 
to make the alleys about 2 feet wide. These alleys are 
often filled with manure to help retain the heat of the hotbeds, 
155. The pit. — Most hotbeds are heated by the fermem 
tation of manures in pits excavated for this purpose. The 
first essential of the pit is good drainage, natural or arti- 
ficial. Artificial drainage may be provided by running 
tile from the bottom of the pit. In most soils, however, 
this precaution is unnecessary. The pit should be dug 
in the fall before the ground is frozen, and a few inches 
of leaves or coarse manure placed in the bottom during 
the winter. It should be of the same width as the frame 
(156) and of any desired length. 
The proper depth of the pit depends upon several fac- 
tors. In the North it is customary to use 15 to 30 inches 
of manure. The pit should, therefore, be a few inches 
deeper than the depth of the manure. For starting early 
vegetable plants in the North, 18 inches of good manure 
is ample, while 24 to 30 would not be too much in for- 
warding the eggplant, which requires a high tempera- 
ture for seven or eight weeks. Tender plants, like tomato 
and pepper, also require more manure. Southward, the 
depths of manure vary from 6 to 12 inches. The kind of 
manure used and the length of time the hotbed will be 
needed also determine the proper depth of the pit. 
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