166 FOREST TREES. 
can be carried safely through the first summer, there 
is not much difficulty in managing them afterwards. 
They are easily scorched by the rays of the sun, so 
that it is absolutely necessary to protect them during 
the hot weather. In the climate of America, what 
is called damping off is perhaps the greatest difficulty 
to contend with. This is the rotting of the stem at 
the surface of the ground, which, if not checked, will 
in some seasons destroy the greater part of the plants. 
It usually occurs while the plants are in the seed- 
leaf, and appears to be caused by a combination of 
heat with too much moisture. It was scarcely seen 
in the dry summer of 1870. The usual remedy is 
the liberal application of dry sand, scattered with the 
hand or from a fine sieve. The sand should be kept 
at hand ready for use. This disease appears more 
likely to occur on rich soils than on those that are 
poor. Young plants of most species grow slowly the 
first two or three years; but some few, such as the 
Gray and Scotch Pines, and the Larch, are compara- 
tively rapid in their growth. 
Late in autumn the young plants receive a light 
covering of leaves, on which is placed straw or small 
branches in sufficient quantity to prevent their being 
blown off by the wind. This will secure the plants 
from being drawn out of the ground by frequent 
thawing and freezing. Straw or marsh hay will 
answer, if leaves are not to be had. 
In removing the plants from the seed bed, the 
strongest are taken out the first or second year, accord- 
ing to their vigor of growth, and the weaker are 
