TUALATIN VALLEY NURSERIES, SHERWOOD, OREGON 
Winter Injury 
Weather conditions have killed and injured more fruit trees than all other causes coni- 
hnied. We consider the most dangerous season of the year to be in very early spring when we 
have bright, warm sunny days, followed by frosty nights, the warm rays of the run starts the 
sap on the south sides of the trees. These clear days of February and early March are followed 
by frosty nights, the frost clinging to the bark chills the freshly risen sap, which soon becomes 
sour, often bursting the bark on the south sides of the trees and causing a gum-like substance 
to issue forth. This is soured sap, caused by thawing and freezing and may be prevented to 
some extent by shading the south sides of the young trees with a board or shake. These should 
be 5 inches wide, 3 1-2 feet high, 1-2 to 1 inch thick, sharpened at one end and driven into 
the ground about 6 inches from the tree, always on the south side so as to keep the sun rays 
from starting the sap prematurely. These protectors should be used for the first three years, 
after which the bark on the trees will have become thicker and will better withstand the sud-* 
den changes of temperature. The protectors may be removed during the summer months, or 
after danger of frosts is over. Sweet Cherry, Apricots and Peaches are the most easily affected. 
However, no harm will be done if the protectors are used on all young fruit trees. 
The Oregon Agricultural College advises a liberal coat of whitewash as a protection for 
orchard trees through the winter. This may be applied on the larger limbs as well as the body, 
but in young trees would suggest that you also use the board or shakes in order to keep the sun 
off of the south sides, for we are certain that the premature action of the sap, caused by the sun 
is the start of the damage caused by the freezing that follows. By using both the whitewash 
and the boards, one would have double protection. 
A True Photo of Ely Improved Elberta Peach. It is Almost Red in Color. 
One of the Finest Peaches Grown. Order Before We are Sold Out. Large 
and Thick as Grapes. 
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