FRAME CROPS 395 
for the growing of the various classes of vegetables in 
coldframes. In many instances it is not so convenient to 
apply manures and fertilizers in frames as in greenhouses, 
and perhaps greater care should be taken to have the soil 
fully and properly enriched before the crops are started. 
Watering.—All that was said in Chapter X about 
watering applies to the moisture problem of frame crops. 
Success or failure hinges on this operation more than on 
any other factor. Evaporation is often very rapid, and 
constant alertness is required in order that the plants do 
not suffer at any time from an insufficient supply of soil 
moisture. It is also important to avoid over-watering 
and to maintain suitable atmospheric conditions for each 
Fig. 137.—Pit or hotbed, showing drainage basin. 
crop. The overhead system of irrigation is often 
employed for frame crops. 
Ventilation.—Sash-covered frames may be ventilated 
in various ways. When there are cross bars the sash may 
be shoved either way so as to give as much ventilation as 
