By Darrell Blackwelder
For the Salisbury Post
A skin rash from poison ivy is a constant concern for those who work outside. In severe cases, the skin rash (dermatitis) may hospitalize its victims. Identification and control of poison ivy is one step in prevention of dermatitis.
Poison ivy is usually found as undergrowth in woods, fence rows, recently cleared lots or growing as a vine on trees. The vine often grows as a low-growing shrub in the absence of trees or other support objects.
The stems of poison ivy are smooth light brown or gray. The leaves are very ornate and shiny with broad, serrated margins. The leaves are trifoliate or in groups of three that produce gray-white berries 1/4-inch in diameter. These berries are actually a favorite food of birds and a major source of the plant’s distribution.
The poisonous substance in the leaves and stems is called hydro-urushiol. The poisonous substance is also found in the roots bark and berries of the plant. The oily substance does not dissolve in water and is not volatile so it easily adheres to a number of objects including pets, clothing, garden tools, golf clubs, guns or fishing rods.
Smoke from burning stems or leaves is another contact source. Splashing sap from stems and twigs when cutting trees is often a source in the winter months while cutting firewood. Physical contact is necessary to obtain the poisonous oil and cause a skin rash.
The susceptibility of dermatitis depends upon the individual. Minute amounts of the oil can cause a rash. The poisonous oil penetrates skin tissues, creating sensitive tissues.
Now is an excellent time to control poison ivy. The best time to control poison ivy is just before and after bloom in the early summer. Brush killers or herbicides that contain dicamba or trichlopyr effectively control poison ivy. Glyphosate or Roundup will also kill the vine.
Carefully follow the instructions provided on the label. Contact the Cooperative Extension Service if you have questions about applying any pesticides. More detailed information on poison oak and poison ivy can be found online at http://poisonivy.aesir.com/view
Darrell Blackwelder is an Extension Agent in horticulture at the Rowan County Center N.C. Cooperative Extension; call 704-216-8970.