A few days ago I visited a homeowner who was clearing by hand brush, vines and under growth on their small farm. The person was surprised when I pointed out the vines were poison ivy. The pile of brush they had planned to burn also contained poison ivy. The smoke from burning poison ivy can cause health problems.
Poison ivy is a common poisonous plant in Georgia. It can mainly be found in moist, wooded areas.
However, it also grows in pastures, fence rows, ornamental plantings and various types of noncropland areas. Poison oak, a related species, is also found in similar habitats.
Each year poison ivy causes contact dermatitis (redness, rash, blisters, itching) to thousands of people. The American Medical Association estimates that in the United States poison ivy and poison oak cause more cases of contact dermatitis than all other plants and household and industrial chemicals.
Poison ivy is a woody perennial that may grow as a small shrub or as a high-climbing vine with aerial rootlets on trees, fence rows and buildings.
In contrast, poison oak usually grows as a small shrub.
Poison ivy reproduces by creeping roots and seed. Leafy shoots can arise from the creeping roots several yards away from the parent plant.
The leaves of poison ivy are alternately arranged on the stem. Each compound leaf consists of three bright green, shiny leaflets. Leaflets are egg-shaped and have either smooth, toothed or lobed margins. The upper leaf surface is smooth, or lacks hairs, while hairs are commonly found on the veins of the underside of the leaf.
Poison ivy leaf shape varies greatly. Leaves with different shapes may be found on the same plant or on plants near each other. People may misidentify poison ivy when they see a plant with an unusual leaf shape.
However, the old saying, “leaflets three, let it be,” should always be followed.
While this approach may cause unjust suspicion of a harmless plant, it is a safe tactic. It is better to avoid a plant you mistakenly believe is poison ivy than to handle one you mistakenly believe is not.
Symptoms of contact with poison ivy include skin inflammation and blistering.
All parts of the plant are poisonous at all times of the year. A toxic, or sensitizing, oily compound (urushiol) is contained in specialized resin ducts in all plant parts.
Humans are commonly exposed as they brush against the plant and bruise the leaves.
They can also be exposed when sensitive people contact the toxin by touching equipment, clothing or animals that have been in contact with poison ivy. Dogs and cats often transfer the toxin to people as stated earlier. The toxin can also be carried on soot particles in smoke from burning poison ivy and cause severe allergic reactions.
Sensitivity to poison ivy varies. Some people are extremely allergic; others are not as sensitive. Following contact with the poison ivy toxin, it usually takes 12 to 48 hours for symptoms to occur. However, with some people, symptoms may not appear for several days.
If contact with poison ivy is suspected, wash the skin with cold water. Don’t use warm water as it helps the oily toxin penetrate into the skin.
Don’t wash the exposed skin areas with soap either as it removes the protective skin soils and can increase penetration of the toxin. Only the oily toxin can spread the rash.
Many topical ointments and lotions are available for treating the symptoms of poison ivy. Consult a physician or pharmacist for the appropriate treatment.
Poison ivy will not tolerate repeated tillage, cutting or mowing. Continually clipping the plant at or near the ground level will eventually control poison ivy.
However, it often takes several clippings during the year and for several years to control it.
Poison ivy shoots commonly encroach from wooded areas into newly established lawns. Herbicide use is not usually necessary as frequent mowing will eliminate the plant from the lawn. But to prevent future encroachment into the lawn, poison ivy should be controlled in the adjacent wooded area.
Digging poison ivy plants and roots can be used as a control method in small beds of landscape ornamentals. Always wear water-impermeable gloves when handling poison ivy plants (including the roots).
Many herbicides are available for control of poison ivy. Before using any read all label directions. Because poison ivy has an extensive root system, herbicides usually have to be applied more than once for effective control. Make repeat applications at the full-leaf stage of growth.
For more information on controlling poison oak or poison ivy with herbicides, call the Dawson County Extension Office at (706) 265-2442.
Clark Beusse is the Dawson County extension agent. For more information, call (706) 265-2442.