118 
ARTIFICIAL ADAPTATIONS OF 
tivated as for a row of garden vegetables. The arbor-vitaes grow 
so naturally into a hedge-form, that little skill is required to shape 
them. The hemlock and other evergreens require much more 
attention. 
Where it is necessary to have a high screen without delay, we 
would plant the Norway spruce, and let it grow pretty nearly in a 
natural way, until it reaches the height needed. The plants need 
not be nearer than two feet apart, and are apt to grow more evenly 
when small trees — say from one to two feet high — are planted. 
Those which grow fastest must be kept back to the same rate of 
growth as the weakest, or the former will in a few years over-top 
and kill out the latter. Further than for this purpose, the lower 
branches should not be cut back unless the top is also cut A ver- 
dant wall of Norway spruce twelve feet high may be grown in six 
years from the time of planting, and must be allowed three or four 
feet on each side of the stems for the lateral extension of the lower 
branches. When the required height is attained, the tops can be 
kept cut to it, and both sides dipt back to the form of the section 
of a cone, the base of which is equal to half its height. The screen 
can thereafter be cut late every June, so as to leave but an inch or 
two of the last growth, and again in September if a second growth 
has pushed strongly. 
It is seldom desirable to make topiary screens more than ten 
or twelve feet high, as the trouble and expense of clipping them 
from a movable scaffold is considerable. Where there is need, 
and room, for higher screens, the object may be attained less 
expensively and less formally with groups and belts of pines and 
firs. But it happens sometimes that a screen of considerable 
height is required where there is not ground to spare for the 
growth of trees in a natural way ; and in such cases it is practi- 
cable to form Norway spruce hedges to any height at which they 
can be clipped, and without occupying for the base of the hedge 
more than from six to ten feet in width. 
In general, hedges should be within a height that a man 
on the ground, with the proper instrument, can cut any part of 
them. 
For evergreen hedges of a defensive character, that is to say, 
