STREET TREES. A” 
the soil thoroughly and also to protect the top from the effect of 
drying winter winds. Where mice abound they may be harbored in 
the mulch and may girdle the tree. This may be prevented by a 
collar of wire netting about the base of the trunk or by banking the 
earth about it. The death of trees at the time of transplanting is 
due to the drying out of either roots or tops before opportunity is 
given them to become reestablished in their new locations. This 
drying may be due to improper exposure at the time of digging or 
before packing (fig. 30), poor packing, prolonged delay in delivery, 
improper handling between unpacking and planting, or the existence 
of conditions conducive to excessive drying out of the plant after 
setting. 
P14340HP 
Fic. 32.—A city nursery. 
The atmosphere is continually claiming a tribute of moisture from 
all living plants, whether the plant is in leaf and growing or is dor- 
mant. Growing plants, and dormant plants under normal conditions, 
are able to replace this moisture by absorption through the roots. In 
climates where newly planted trees may obtain sufficient soil water 
to replace these losses by drying, fall planting is best. Where the 
plants are unable to get sufficient winter moisture, planting would 
better be done only in the spring. Where the soil freezes to a depth 
greater than that to which the plant roots extend, the supply of water 
is cut off from the roots and the tree will be killed by drying out 
through evaporation from the top. Where winter winds are very 
drying and the soil moisture is limited, evaporation from the top is 
likely to be in excess of that supplied by the roots and the tree is 
killed in the same way. ) 
