Evening star., 1961-06-09
BY BILL YOUNGMAN
Star Garden Editor

ny DILL IOONUMAN
Star Garden Editor
Along with the flowers we
get the weeds, and one of the
worst is poison ivy. 1t shows
UP in nearly every garden
sooner or later because the
birds scatter the seeds far and
wide. Since it is irritating to
many the gardener should be
prepared to recognize and ex-
terminate each Ind every plant
of poison ivy as it shows up.
The three leaflets of the
common poison ivy usually are
notched, sometimes have a
serrated edge. but more often
are smooth edged. At this sea-
son the leaflets are somewhat
ruddy in color but this will
soon change to a rich green.
Poison ivy used to be rather
difficult to kill for then the
gardener had only such rem
edies as salt, crank-case oil,
and digging out the roots by
hand. These materials would
do the job if properly handled,
but only the foliage should be
wetted and any drippage onto
the ground would mean a bare
spot, if not injury to desirable
plants. 1t took several appli-
cations to do the job since
these materials only killed the
leaves and by repeated ap-
plications the roots were
starved to death.
Then ammonium and sodium
chlorate came along. They
were more potent to plant life
but the risk of use was greater
since they rendered clothing
and other materials exploSively
inflammable.
Newer Remedies
Then came ammonium sui
famate, 2,4-D, ammonium
thiocyanate. borax. carbon Gi-
sulfide, coal-tar creosote oil,
and sodium arsenite, listed in
the approximate order of their
effectiveness. Less effective
were calcium cyanamide, am
monium sulfate and iron sui
fate.
This parade Of chemicals
and methods of fighting the
poison ivy is some indication
Of the seriousness Of the prob
lem. The materials listed above
for the most part killed only
the leaves and so repeated ap-
plications were needed to kill
the underground roots.
Most recently, amino triazole
gained much attention because
it could be sprayed on the
dogwood and poison ivy plant
ings at Valley Forge, killing
the ivy but not harming the
dogwood. Moreover, one ap-
plication has been effective in
most cases, but this is difficult
to prove since there are al
ways new seedlings appearing :,
Be that as it may, amino
triazole is considered the most
effective poison ivy killer
available to the home gardener
today. 1t is also known
as amitrol, another common
name.
Early Control Best
Early in the season the poi
son ivy foliage seems to stand
alone, but later in the season
it is likely to be mixed with
other foliage. Thus early sea-
son control is advised since
then it is often possible to
spray the poison, ivy foliage
without too much of a prob
lem shielding other foliage
from the spray.
Oftentimes the poison ivy
may be found clinging to the
trunk of a tree. If the tree
bark is thick there is little
likelihood of spray injury il
the spray is directed to the
leaves and there is a minimum
of drip onto the ground.
Poison ivy seems to be most
subject to chemical control in
the spring although many have
successfully killed it with
amino triazole in late summer.
Dead poison Ivy plants can
be just as injurious as green
ones. The smoke from a burn
ing pile of poison ivy is very
dangerous since the fumes will
irritate the lining Of throat
and nasal passages.
The chemical controls out
lined above are primarily for
eradicating heavy growths.
Once they have been cleaned
up it is quite feasible to con-
troll the new seedlings by sim
ply pulling them as they ap-
pear-well before they are
deeply rooted. The alternative
is to use one of the aerosol
cans containing amino triazole
for spot treatment.
All this sounds so simple
and easy to implement but