108 ELEMENTARY FORESTRY. 
cans laid on their sides, so they may be readily found in spring 
and will not be liable to poison the birds. When seedlings are 
thrown out of the ground by frost they should be pushed back 
and have the earth pressed against them as soon as the ground 
is thawed in the spring. 
Late Spring Frosts are common in the low lands of this 
section. They injure the trees by killing the new spring growth 
after it has started several inches. A large number of trees are 
seriously injured in this way, and are classed as frost tender 
trees, and those that are not liable to this injury are terméd 
frost hardy trees. Among conifers the spruces and balsams 
are much injured by late spring frosts, while our pines and the 
Tamarack, Red Cedar and Arborvite are seldom if ever injured 
in this way. Deciduous trees recover from such injuries more 
quickly than evergreens. Among the deciduous trees most lia- 
ble to injury from this cause are the Ash, Mulberry, Oak, Maple, 
Basswood, Black Walnut, Butternut and Boxelder, though they 
do not ali suffer in the same degree. Among those that are not 
sensitive to late frosts are the Elm, Willow, Poplar, Birch, Hack- 
berry, Wild Black Cherry and Mountain Ash. 
On account of this liability to injury from late frosts, it is 
customary to study the probability of damage from this cause in 
given locations, and to plant accordingly. It will often be found 
that in certain low spots there is greater liability to late frosts, 
while there is very little injury from this cause on the higher 
lands. It is customary among European foresters to protect 
young seedlings of some kinds, particularly Beech, from late 
frosts until they get up off the ground. For this purpose Birch 
twenty or more feet high are encouraged at intervals of thirty or 
forty feet, and the frost tender plants, such as Beech and Spruce, 
are set out between. The result of this arrangement is that the 
Birch, which is frost hardy, quite successfully protects the frost 
tender trees below it. After the frost tender trees are well off 
the ground, as ten or fifteen feet high, there is comparatively lit- 
tle danger from this source of injury, and the Birch is removed. 
Sleet Storms occasionally do much damage by breaking the 
limbs. Little can be done to relieve the trees, but preventive 
measures may be taken. If no large crotches are allowed to 
form in trees, and growth kept as near as possible to one cen- 
tra] shaft, or the longer branches shortened so as they will not 
