33 
jecting them to frost attack. This top-dressing not only tends 
to preserve a more uniform soil temperature, with gradual instead 
of sudden changes, thus preventing lifting and heaving so fatal 
to plants of this kind, but it also enriches the soil. In the spring 
the ess ehould De dau lde ue finer nar Pace into the 
beds. before 
winter sets in, so do not need protection Seance frauispiration of 
moisture through bark and leaves. 
Trees and shrubs offer another problem, for in these the stems, 
and also the leaves in the case of evergreen plants, are present 
throughout the winter. Transpiration of moisture takes place 
through both stem and leaves, so we can understand why it is 
such plants are more difficult to cultivate in wind-swept situ- 
ations. In deciduous trees and shrubs, those which shed their 
leaves a fall, this difficulty is not so serious, for the tran- 
spiration is not excessive. But even here the selection of some 
sheltered ae will es see us to cultivate species, which 
would otherwise be out of the question. Great benefit may be 
derived from placing a top-dressing three to five inches deep 
around the fee especially if newly planted in the fall. This 
is shown the accompanying illustration, plate CVIII., of a 
sie of lilacs presented to the Garden this fall by Mr. 
T. A. Havemeyer. Old manure, free from amm may be 
used. This serves, as in the case of the ee mene: to 
preserve a more uniform soil temperature, and to prevent the 
drying out of the soil around the plants 
It is, however, in the evergreens that we meet with our most 
serious problems. By evergreens are meant all plants which 
retain their foliage green during the winter. These are generally 
divided into broad-leaved evergreens, such as the rhododendron, 
laurel, Japanese holly, and box, and the conifers, such as pines, 
hemlocks, spruces, and firs. Here the large surface offered by 
the foliage exposes the plants to a severe drain upon their vitality 
if placed in wind-swept situations. It does not seem to 
cold which does the damage, but the warm dry winds of late 
March and early April, when we are ee ie ourselves. 
that our plants have come through the winter well. Then let 
