who has ever experienced the blisters, swelling and extreme itching
from an unfortunate encounter with poison ivy learns quickly to
avoid it whenever possible. Poison ivy is a weed of non-cultivated
sites, flourishing along stream banks, roadways, fencerows and woodlands.
ivy (Toxicodendron radicans) has a characteristic compound
leaf consisting of three leaflets. The leaflets are two to four
inches long, dull or glossy green with pointed tips. The middle
leaflet is generally larger than the two laterals. The margins of
the leaflets are variable, appearing irregularly toothed, lobed,
or smooth. The leaves are positioned alternately on the stems. Virginia
Creeper, a non-poisonous vine often mistaken for poison ivy, has
five leaflets radiating from one point of attachment.
courtesy of Rutgers Cooperative Extension
ivy can be found in one of three forms; as an erect woody shrub,
a trailing shrub running along the ground or a woody vine. The vine
is usually seen growing on trees or other objects for support. It
has aerial roots along the stem that give it the appearance of a
"fuzzy rope." Yellowish-green flowers occur in compact clusters
in leaf axils in June or July. The waxy, berry-like fruit is grayish-white,
approximately 3/16 inch in diameter, and has distinct lines marking
the outer surface.
blistering rash caused by poison ivy is the direct result of contact
with the oily toxicant known as "urushiol." Urushiol is found in
resin ducts within the plant's phloem. These ducts are found throughout
the plant, including the roots, stems, bark, leaflets and certain
flower parts. The plant has to be crushed, broken, or in some way
injured to release the resin. The injury may be something as minor
as an insect chewing on the plant. Once urushiol is released, it
can find its way to skin by direct contact with the plant and then
spread by touching other parts of the body.
the sticky, oily substance is easily transmitted, there are indirect
ways to contact it, for instance, from the fur of a pet, garden
tools, garden gloves, clothing, golf balls or other objects that
have come in contact with an injured plant. Contrary to popular
belief, the rash from poison ivy cannot be transmitted from touching
the oozing blisters.
you know you have contacted poison ivy, wash the area as soon as
possible with soap and cool water. Warm water may cause the resin
to penetrate the skin faster. Because urushiol can penetrate in
a matter of minutes, you may still get a rash, but at least you
have contained the infected area. A visible reaction, redness and
swelling may be apparent within 12 to 24 hours.
your family physician or pharmacist for recommendations for effective
non-prescription medication. Exposure to the smoke of burning poison
ivy can also cause a rash. Be careful not to burn wood with the
poison ivy vine attached to it. Take extreme caution to avoid inhaling
smoke or contact of smoke with skin and clothing.
There are three effective methods for eradicating poison ivy in
ornamental beds: hand pulling or grubbing; severing the vine and
then treating the regrowth with an herbicide; application of an
herbicide to individual leaflets.
pulling is most successful when the soil is moist. The roots can
be dug and pulled out in long pieces. Care should be taken to remove
the entire root because the plant can resprout from sections of
root left in the ground. Avoid skin contact by wearing gloves while
you work and washing clothing and gloves immediately after. The
washing machine should be rinsed thoroughly afterward to eliminate
the possibility of contaminating other clothing. Vines growing on
trees can be difficult to pull out of the ground because their roots
may be entangled with the tree's roots.
Sever the vine at the base and carefully pull it out of the tree.
Glyphosate (eg., Roundup or Ortho's Kleeraway Grass & Weed Killer),
a non-selective, translocated herbicide, can be applied to the new
shoots that will soon emerge from the base of the old plant. This
herbicide is most effective if applied to actively growing foliage
two weeks on either side of full bloom, in early summer. Another
herbicide that may be used is triclopyr (eg., Ortho's Brush-B-Gon
Poison Ivy Killer). Poison ivy is difficult to control, even with
herbicides--neither glyphosate nor triclopyr will provide complete
control from a single application, and repeat applications to treat
regrowth may be necessary. Other herbicide brands or formulations
may be found at your local garden center. Be sure to read the label
to ensure that poison ivy is listed on the label, then follow the
from Cindy Welyczkowsky and Jane C. Martin, Ohio State University