List of Shrubs 323 
stature, which keeps them under the protection of snow, 
nearer the warming iniluence of the ground, and more out 
of reach of searching winds. ‘Their habit of suckering from 
the root is also of value, replacing more readily the lost stems 
or parts. Indeed, when dealing with half-hardy shrubs, it 
is often wisest to cut them down io the ground in the fall, 
when the roots next spring will reéstablish them. These 
half-hardy species whose annual shoots are apt to be killed 
back from one-quarter to one-half require in a northern 
climate, such as that of New York or New England, or Can- 
ada, sheltered situations or artificial protection to enable 
them to stand the winters. A common method is to bend 
them down to the ground, weighting them with stones, 
when they will be covered by snow, and winter well. Con- 
cerning this question of hardiness we refer again to Chap- 
ter IIT. 
The low, spreading habit of shrubs furnishes protection 
to the soil, keeping weeds out, and reducing evaporation, 
while their shallow root system adapts them to shallower 
and poorer soils. 
Most shrubs are tolerably free from insect and fungus 
pests, and, if they are attacked, are more readily protected. 
They are, as a rule, easily propagated, but, to secure the best 
persistent effects in form, foliage, and flower, the applica- 
tion of the pruning knife is essential. Their more or less 
read; ~esponse to this treatment makes them specially avail- 
able for hedges or borders. 
Besides adaptation to climate, soil, and exposure, shade- 
endurance is a point of value in many, making them useful 
as underbrush. 
Form is of less moment than in trees, as it can be more or 
less readily corrected, but size is of importance, when group- 
ing is attempted; for while some species may be kept down 
