38 The: Colorado Expe;rime:nt Station. 
ing and ventilation. 
It is better to water the bed with a watering pot than with a 
hose because there is less tendency to pack or puddle the soil. The 
bed should not be watered toward night, as this tends to lower the 
temperature when the outside temperature is falling. Too much 
water checks the heating of the manure and must be avoided. Wet 
the soil thoroughly (but not too wet) and then do not apply any 
more water until the plants show that they need it. 
Ventilation is particularly important. On warm days, the 
combined heat of the sun and fermenting manure will be enough to 
destroy the plants unless the hotbed is properly ventilated. Ven¬ 
tilation can be given by sliding down the sash or by propping it up 
a few inches. When the time approaches for setting the plants in 
the open, the sash should be removed entirely when the weather 
permits. In this way the plants become accustomed gradually to a 
lower temperature and the normal conditions of the atmosphere. 
Whenever the air in the hotbed is so moist that drops of water col¬ 
lect on the panes, ventilation should be given if the temperature will 
permit. Plants which are kept in a close moist atmosphere tend to 
grow too tall and soft. 
In very cold weather or during snowstorms it may be neces¬ 
sary to keep the sash and mats over the hotbeds for several days at 
a time. In this case, the plants are in the dark and tend to become 
soft and tender, so that care must be used in admitting light after 
this period, as they are likely to be scalded by the sunlight. 
The hotbed should not be started too soon. If it is to be used 
for starting plants which are to be transplanted to the field early in 
the spring, it should be made from five to eight weeks before time 
to set out the plants. If they have to be held back on account of 
the cold weather and not transplanted, they will become stunted. 
The average life of a hotbed is about two> months. A good size 
for the ordinary garden is 6x12 feet, requiring four 3x6 sash. It 
is a good idea to fill the pits with litter of some kind in the fall. 
When the time for making the hotbed arrives, this litter may be 
pitched out, leaving an unfrozen area for the making of the hotbed. 
COLD FRAMES. 
Cold frames may be either temporary or permanent structures. 
If temporary, they are boarded up with the same material as the 
temporary hotbed, that is, one-inch plank. Cold frames are made 
the same size as hotbeds and have a slope to the south. Glass sash 
and mats- are used for covering them, or the muslin cover described 
under hotbeds may be used after about the 20th of April. 
When the cold frame is to-be used for growing lettuce or for 
