The Van Buren press., 1898-05-14
WHAT KILLS CITY TREES.
tmpregnation of Soil with Gas Poisona
Roots, Which Gradually
Shrivel and Die.

According TO the gardeners, the pfln, |
cipal reason why trees do not do we'll in
our city streets is because of the i'm.
pregnation of the soil with gas. Some
trees are less sensitive than others, per-
haps the best ones being our common
poplar, but no tree can long Withstand
the effects of leaking gas mains near its
roots. The trees in the parks have es-
capped eontagion so far, but in most OF
city streets the tainted soil now renders
the growth of good specimens impossi'
BILE.
There seems to be no valid reason why
the soil should thus become impreg.
mated with gas, but that it is so is made
evident every time tree is opened. Al
together an enormous amount of illu.
minating gas must be lost every year
through leakage in the mains, loss rep
resesfing a considerable sum of money
yet against which no special steps have
been taken. The effects of the gas on
the city's trees are least of all con.
sidered. In Europe, and especially in
France, they do better, When city
tree dies there the cause is promptly
determined by an investigation. If il
is found to be due to an excess of illu.
minating gas in the soil the gas company
is required to replace it. If this is not
done at once a new tree is planted by
the city and the cost is charged to the
company.
As the cost of planting city trees is
quite heavy, where the work is properly
done, the gas companies in Europe are
very careful in laying their mains, and
| the leakage is small as compared with
that in New York. In France the cost
of planting ranges, from about s0d
francs $500 upward for each tree. Each
tree is surrounded by an open space not
| less than 10x15 feet, so arranged that
! the pavement about n drains into it and
keeps the roots well supplied with
water. The open spaces are covered
with iron gratings, which permit the
| free passage of air and water, but pre-,
vent any possibility of mud. When
| tree is to be planted all the soil is re-
moved from the site and replaced with
fine earth specially mixed and enriched
for each variety of tree. This treatment
is expensive, but it pays, for the trees
grow vigorously and require no atten.
ton, other than little pruning, for sc
years or more.
Something of the same system has
been adopted by our park board. The
trees set out last year in Riverside park
were placed in specially prepared sol
and We're surrounded by open spaces, sc
as to permit free access to air and water
but we are not yet using gratings over
the spaces. In the case of old and deep
rooted trees, the subsurface flow OF
water may supply sufficient moisture
but air, which is quite essential to
healthy growth, is almost entirely cut
off from the roots by asphalt and other
waterproof pavements. The sol
throughout most of the city is a thin
gravel, and the tree food in it is very
soon exhausted if it is not thoroughly
enriched before planting.
1t is probably on this accountable
impoverishment of the soil-that the
evergreens which were once the pride
of the west side of Central park have
now almost disappeared. Perhaps, also
the absence of lime in the soil has hac
some effect upon them. The last re-
port of Mr.. Rose, superintendent OF
parks, to the park commission called at.
tention to the condition Of these ever.
green's, and it is probable that i'm
mediate steps wiliibe taken to replace
those which have died. Nearly all the
evergreens are of exceedingly slow
growth, and prompt action is necessary
ii the present generation is to derive
any benefit from the proposed replant
ing. On the city streets, however, it Is
doubtful whether tree culture coul6
be made successful without some meas
ure which would prevent such whole
sale leakage from the gas mains as pre-
walls at present.-N. Y. Commercial Ad