ARBOR DAY NUMBER 
BROOKLYN BOTANIC GARDEN 
LEAFLETS 
THE BROOKLYN INSTITUTE OF ARTS AND SCIENCES 
Series II Brooklyn, N. Y., April 22, 1914 Number 3 
TREE PLANTING 
Arbor Day in each State is a day set apart for the planting of 
trees and for the consideration of how valuable trees are to man. 
The early spring or the late fall are the best seasons for planting 
those trees that shed their leaves in autumn. Some people prefer 
spring, others fall, but for most trees that shed their leaves each 
year it does not greatly matter which of the two seasons is chosen. 
The greatest need of trees, as indeed of all plants, is a proper 
amount of water. Therefore the most important point in trans- 
planting is the water supply. Plants take in water almost entirely 
from the soil through their roots, while they lose it continually by 
evaporation from their leaves so long as the foliage remains on. 
This is why early spring and late fall are the best seasons for 
transplanting. In early spring the leaves have not yet appeared, 
so that water is not being lost by evaporation; but the roots are 
already active, new ones have time to grow, and the entire root 
system has a chance to become sufficiently established to take in 
water as fast as it will be lost when the leaves begin to appear. 
When trees are transplanted in late autumn, the leaves are 
falling, or have all been shed, but the roots may continue to grow 
in the soil for several weeks, before the ground freezes or becomes 
too cold for them to grow. When spring returns, the roots again 
become active before the leaves appear, and thus sufficient water 
supply is insured as soon as the leaves put forth from the opening 
buds. 
Evergreen trees, which never shed all of their leaves at any 
one time, may be transplanted to advantage in August and Sep- 
tember; for, although their leaves remain on, they become less and 
less active and give off less water as winter approaches. The ac- 
tivity of the roots continues, however, for a longer period, and 
vigorous enough to supply water as fast as it is evaporated from 
the leaves. It is claimed by many expert tree movers that if ever- 
greens are transplanted in the spring the leaves are liable to 
become active, and thus lose water in large quantities before 
