Evening star., 1911-01-22

other words, the experts OF the
laboratory of forest pathology
Of the Department of Asrlcul-
ture-haye come to extend their
services from the public domains " 'hoSe
of private individuals.
According to the governments sylvan
physicians there exists a widespread lg-
norance regarding the diseases of trees.
even among those who own conslderaule
wooded estates. 1t may be novel infor-
nation to some, for instance, to near
that trees are subject to respiratory all
ments, colds. poisoning from various
causes heart disease. etc. and that each
of these pathological conditions requires
careful diagnosis and expert treatment
The time-honored poem. 'Woodman,
Spare That Tree is an eXempliiication
of the sentimental interest often attach
ing to a particular tree or trees on the
part of the owner, and this feeling is IL
lustrated-in some instances rather
auaintly-in communications received at
the bureau Of plant industry.
What all correspondents desire to
know said Haven Metcalf, who is pa
tholosist in charge of the laboratory, is
What is the matter with the tree or
shrub in question and how can it be
cured?'
often no satisfactory answer can be
given. Trees are particularly subject 10
troubles which are wholly due to ab-
normal conditions in their immediate
surroundings and which call for actual
inspection of tree and surroundings IN
order to diagnose the case. Or there often
is no cure in the nature of the case; for
example, there is no cure for old age.
-.
Speaking generally. the most wide
spread cause Of disease of trees and
shrubs is the attempt to grow them in a
climate and situation for which the par
ticular species is not adapted. For ex-
ample, such evergreens as the English
yew. Scotch pine. and Irish juniper have,
for sentimental reasons and in accord
ance with horticultural tradition, been
planted extensively IN the eastern states.
Unless in favorable situations ana haHlnS
exceptional care, these tree iinmisrants
are short-lived, ragged and susceptible
to many diseases. There is really no
need for the cultivation of such imported
varieties, as in general the same enects
may be obtained with native varieties or
with varieties imported from regions OF
similar climate. II such trees are planted
and to those named may be added. or
late at least. the Austrian pine, the
silver fir and the Norway spruce-it
should be with the understanding that
they must receive extra care.
1t is found by the government patholo-
eists that disease is more apt to attack
a city than a country tree. For example,
when one Of the parks in this city is
cleared of underground in order that the
lawns thereof may assume that smooth
and verdant aspect for which they are
notable. the trees in such parks are men
aced by the very operation which beauti-
fies and makes trim the velvety carpet
Of grass. Such clearings, 1t Is explained
by the expert, result at first in greatly
stimulating the growth of the trees. but
they also cause rapid loss of nutriment
to the soil surface. with the result that
the trees may soon come to suffer from
lack Of both food and water The tree
doctor prescribes in this case. fertilizer
applied to the surface of the ground.
One of the most difficult of diseases at
fecting city trees to diagnose is gas poi
soning. Illuminating gas often finds its
way to the roots from leaks i'm the pipes
When trees in any locality within city
limits die suddenly without obvious