Poison Ivy Control
Heed all warnings. Check with your physician if you
have any concerns regarding your personal health risk.
Revised by Tom Ellis, M.S., Department of Entomology
Poison ivy (Toxicodendron radicans) is found in nearly
every part of Michigan. lt is known by several different
names, such as three-leaved ivy, poison creeper, climbing
sumac and poison oak. Although it can grow as a self
supporting, erect woody shrub, its usual growth habit is
as a slender vine running along the ground, or growing on
shrubs and trees. The vines can grow to several inches in
diameter over a period of years.
Poison ivy has three leaflets occurring alternately
along the stem. Leaflets are usually smooth, but may be
either a dull or glossy green. Leaf margins (edges) can
be smooth, toothed, and/or lobed. Leaves on the same vine
often have a number of color and leaf margin
combinations. It is possible, however, that all leaves on
a vine will have the same general character. Because
there are no distinguishing characteristics to warn an
unsuspecting individual that a vine is poison ivy, the
old saying of "leaflets three, let it be" should be
remembered.
The flowers of poison ivy are typically inconspicuous
and arise in clusters above the leaves. The berrylike
fruit has a smooth waxy appearance and is gray to white
in color. After the leaves drop in the fall, the berries
are a distinct identifier the poison ivy plant. As a vine
climbs shrubs and trees, it produces numerous "aerial
roots" which attach to the tree or shrub. The "aerial
roots" give the vine a characteristic appearance often
described as looking like a "fuzzy rope."
Poison ivy plants produce an oil called urushiol,
which is usually capable of causing severe skin
irritations the year around. There is always the
potential of transferring some of the oil present in the
leaves, stems, fruit, roots or flowers of the poison ivy
plant to the skin Although contact with the plan is
normally the method of exposure, an individual can also
be exposed by handling clothing, tools, objects or
animals which have become contaminated with the oil or by
smoke from burning the plants.
Two general methods of control of poison ivy are
culture and chemical. Cultural methods should not be
attempted unless the individual is tolerant to poison
ivy. Individual sensitivity to poison ivy varies greatly.
Natural immunity is originally present in all persons,
but is lost after the first contact with the oil.
Subsequent contact with the oil will result in skin
irritation, although severity of the reaction may vary.
Therefore, always take care when attempting to eradicate
this plant. Individual must also be careful when us in
chemical methods so that desirable plants are not
mistakenly killed or injured. ALWAYS READ AND FOLLOW
LABEL INSTRUCTIONS FOR ANY HERBICIDE USED AROUND THE
HOME.
Burning is not a recommended method for eradication.
Burning produces soot particles which carry the oil into
the air. Individuals coming in contact with the smoke
will experience severe cases of poisoning. Poison ivy can
usually be dug out when the soil is wet and there are
only a few plants. However, attempts to remove roots from
dry soil are futile. Pieces of root remaining in the soil
may sprout and replace the original plants. Plowing is
also of little value, since the disturbed root systems
will sprout. Repeated cutting of the plant back to the
ground surface will eventually starve the root system
and the plant will die. However, repeated cutting
increases the chances of exposure to the toxic oil.
Several herbicides are effective in the control of
poison ivy. Most of the products listed in this bulletin
can be found in premixed or easily used formulations at
local home and garden centers. Other chemical products
will control this plant, but may not be registered for
use around the home and are designated as Restricted Use
products (RUP). If these chemicals are required, contact
your local county Extension office for procedures on
becoming a certified application and for the location of
a local commercial pesticide distributor for product
availability.
There are numerous company and store brand names for
the herbicides which control poison ivy. The label on
each product will list the name of the active ingredient
and its concentration. If the chemical will control
poison ivy, it will be stated on the label. The label
should list poison ivy and give the proper rate to be
applied, along with other details on proper application
procedure. Several commonly used herbicides that control
poison ivy are: Glyphosate, Amitrole, 2,4.D, Triclopyr
Other chemical products may also be used to control
poison ivy. Although they may not be registered for
residential use, they are available for use in other
situations, such as along fence rows, in fields, or in
wooded areas. These products include dicamba (Banvel),
hexa-zinone (Velpar), 2,4-D ester + 2,4-Dp ester,
picloram (Tordon), and sulfometuron methyl (Oust).
For specific recommendations on the use of these
chemicals, contact your local county Extension office,
found under local government in the phone book