An irritating plant...
POISON IVY is a woody shrub or vine with hairy looking aerial roots. It grows
to 10 feet or more, climbing high on trees, walls and fences or trails along
the ground. All parts of poison ivy, including the roots, are poisonous at all
times of the year.
The toxin in poison ivy is an oil which causes an irritating skin reaction on many people. The reaction, an itchy rash with clear blisters, is variable in severity among people, and can vary from year to year on the same individual.
The poison ivy reaction can be reduced if you change clothing immediately and wash the exposed skin with soap and water. if you can wash all the oil off exposed skin within 5 minutes of contact, no reaction will occur. Even water from a running stream is an effective cleanser. The oil from poison ivy can remain active on clothing and footwear as long as a year so be careful not to expose yourself to the oil again. The oil can also be transmitted on pet fur and in the smoke of burning poison ivy.
YOU CAN USE various products such as MultiShield applied prior to anticipated exposure or Tecnu Skin Cleanser to cleanse exposed skin. However, the best way to avoid the irritating rash is being able to identify poison ivy.
...and a good plant
POISON IVY is a nuisance to people but compensates by having considerable wildlife value.
The white, waxy berries are a popular food for songbirds during fall migration and in winter when other foods are scarce. Robins, catbirds and grosbeaks especially like the berries. Many birds feed on insects hiding in the tangled vines. Small mammals and deer browse on the poison ivy foliage, twigs and berries.
IDENTIFICATION
POISON IVY is commonly confused with other plants. Here are the key differences to look for to distinguish poison ivy from its lookalikes:
Poison ivy
- three divided leaves
- center leaflet on a longer stalk
- white, waxy berries along the stem
- leaves alternate on the stem
- erect shrub or climbing vine
Fragrant sumac
- three divided leaves
- center leaflets not on a stalk
- red, fuzzy berries at the end of stem
- erect shrub
Box elder
- three to seven divided leaves
- leaflets pinnate like a feather
- leaves opposite on stem
- erect tree
Virginia creeper
- three to five divided leaves
- leaflets palmate like an outstretched hand
- blue-black berries along the stem
- trailing or climbing vine
CONTRARY TO POPULAR BELIEF, poison oak is found only in a few counties in extreme southern Missouri. Another common misconception is the belief that poison sumac or shumac grows in Missouri. This shrub or small tree resembles smooth sumac but has never been found in the state.
CONTROL
POISON IVY CONTROL can be done at any time of the year, but is best achieved May through July while the plants are flowering. Poison ivy should be accurately identified before you attempt any control measures. Spraying is recommended over burning because poison ivy oil vaporizes when hot, carries in smoke and can cause a severe rash.
Poison ivy foliage within reach can be sprayed with glyphosate (sold under the trade names Roundup, Kleenup and others) according to label directions. When using this or any herbicide, always read and follow label directions carefully. Take care to avoid other plants and do not spray so heavily the herbicide drips off the leaves. Glyphosate is a nonselective herbicide and will kill any vegetation it contacts.
To kill poison ivy that climbs high into trees, cut the vine off 6 inches above ground level. Treat the stump with glyphosate (according to label directions) immediately after cutting to kill the roots and prevent sprouting. If resprouting does occur, treat the leaves with glyphosate.
Poison ivy can be very persistent, so you may have to spray the vines two or more times for complete control. Poison ivy can spread along fence or hedge rows and under trees by birds dispersing the seeds. Treating young seedlings with glyphosate will kill them and limit the spread of poison ivy.
For more information, contact: Missouri Department of Conservation, P.O. Box 180, Jefferson City, MO 65102-0180
Content revision: 20030707
