he longevity of a tree is
important. The desire for quick results often outweighs other
considerations. Many of the trees which give results such as silver
maple, box elder and Carolina poplar do not last long and the effort
spent on them is wasted. More time and money is needed within a short
time to remove and replace such trees. It is better to plant well in the
first place. Trees do not grow at the same rate throughout their life.
They usually grow slowly at first and then fairly rapidly between the
tenth and thirteenth years, after which the rate of growth usually falls
off gradually. If small trees, about ten feet high are used for planting
they should reach the following sizes in twenty years on favorable soil:

American elm 18 inches
Basswood 15 "
Chestnut 12 "
Hard maple 11 "
Red oak 11 "
Pin oak 9 "
White ash 9 "
Black walnut 8 "
Hackberry 7 "

Certain trees such as the horse chestnut and the evergreens generally
appear to better advantage alone or in groups while others like the
elms, maples and box elder show to fine advantage in long rows. It is
doubtful if the planting of windbreaks along the highways is advisable.
Windbreaks are sometimes planted with the idea of preventing the
drifting of snow but the snow will collect and form great drifts on the
leeward side of a windbreak and the shade from the windbreak may prevent
the snow from melting so rapidly. Hedges may be used, however, to
prevent the shifting of sand or the erosion of steep slopes.

The highways offer excellent opportunities for nut production and such
trees as the black walnut and hickories may often be used to advantage.
The presence of birds may be encouraged by planting hackberry and other
trees or shrubs of which they are fond.

The Michigan Agricultural College was authorized by the Legislature to
raise trees for roadside planting. The College is raising red oak, black
walnut, oriental sycamore, sugar maple, elm, hackberry, snowdrop tree,
Juneberry, hickory, European larch, Norway maple and box elder for this
purpose. Other trees may be added to the list from time to time.

In addition to the planting of trees we need also the proper care of
those already planted or growing naturally along the roads. The
commonest source of injury is due to improper pruning for telephone
lines. A great many trees are badly injured in this way. We already have
a large investment in