Plants as Affected by Cold. 115 
are subjected to drying wind, which evaporates their water, 
while the frozen condition prevents movement of their fluids. 
d— The frequency with which freezing and thawing are 
repeated. Frequent slight freezing and thawing are far more 
injurious than a prolonged frozen condition, even at a much 
lower temperature. Winter wheat and rye, and strawberry 
beds are often more damaged in mild winters, in which 
freezing and thawing weather alternate, than in more severe 
ones, when the temperature is mostly below freezing. The 
chief damage is usually done to these crops in late autumn 
and early spring. 
e — The previous treatment of the plant. Plants grown by 
artificial heat may be far less able to endure cold than 
others of the same varieties grown in the open air, possibly 
owing to the more succulent condition of the former. 
Gardeners “harden” plants grown under glass, by gradually 
exposing them to the cooler out-door atmosphere, before 
removing them to the open ground. 
f— The treatment of the frozen tissues. Handling plants, 
fruits or vegetables while frozen greatly aggravates the 
damage done by the frost, probably because the handling 
increases laceration of the cells by the ice crystals within 
them. 
191. Frost-Injured Plants, Fruits or Roots May 
often Be Saved from serious damage, if promptly placed 
under conditions that cause the slowest possible thawing of 
the tissues, as shading from the sun’s rays, immersing in ice 
water or covering with snow. They should be handled as 
little and as carefully as possible while frozen. The mere 
sprinkling of cold water often suffices in the case of frost- 
bitten plants. 
