VEGETABLE GARDENING 
158 
rising, and in very cold weather it may be best not to 
remove the mats at ali from cold frames for a few days 
or even as long as a week in extreme cases. In March 
there may be heavy falls of snow with zero weather for 
many days, with little or no sunshine. Under such condi- 
tions it is better not to remove mats. While the plants 
do not grow when thus excluded from the light, they 
will not be injured by close confinement at low temper- 
atures. 
FIG. 42. FRAME OF HARDENED CABBAGE PLANTS 
The durability of straw mats depends largely upon 
care. When deep snow covers the mats, it should be 
shoveled off before an attempt is made to remove them. 
When they are wet or covered with an inch or two of 
snow, the best way to remove them is to walk along the 
lower side of the frame, grasp the mats at the cords and 
double them over as far as possible toward the other 
side. Then go to the upper side of the frame and draw 
