Poison Ivy Pest Note

Poison Ivy - What is it?

Poison ivy is a straggling or climbing woody vine that's well known for its ability to produce an oily resin called urushiol, which is a skin irritant that causes an itching rash for most people, technically known as urushiol-induced contact dermatitis. Poison ivy can be found in every province except Newfoundland . It grows on sandy, stony or rocky shores, sprouts in thickets, in clearings and along the borders of woods and roadsides. This glossy perennial can spread by seed or by producing shoots from its extensive underground stems.

The compound leaves of poison ivy consist of three pointed leaflets; the middle leaflet has a much longer stalk than the two side ones. The leaflet edges can be smooth or toothed but are rarely lobed. The leaves vary greatly in size, from 8 to 55 mm in length. They are reddish when they emerge in the spring, turn green during the summer, and become various shades of yellow, orange or red in the autumn.

The plant stems are woody and of two kinds. The most frequent kind grows as a trailing vine, with upright leafy stalks 10 to 80 cm high. The second kind is an aerial vine that may climb from 6 to 10 m high on trees, posts or rough surfaces.

The plant produces clusters of cream to yellow-green flowers during the months of June and July. The berries that appear by September are clustered, globular, waxy, and green to yellow in colour. The size of the berries ranges from 3 to 7 mm in diameter, and they often remain on the low, leafless stems of the plant all winter.

Poison ivy is often mistaken for similar plants such as poison oak and poison sumac. Poison oak has the most "oak-looking" leaves of any of the species. It usually has multi-lobed leaves, no aerial roots on the stems, and fuzzy fruits and leaves. Poison oak is not found in Canada except for a western species that grows in southern British Columbia .

Poison sumac, which tends to grow in wet soil conditions, has tiny sweet smelling flowers in the spring and is brightly covered with lovely red and yellow leaves in the fall, with 7 to 15 leaflets. Poison sumac never has only three leaflets, and is the only one of the three that has cream coloured berries.

Poison ivy, poison oak and poison sumac can all cause dermatitis from the urushiol in their sap. When in doubt, avoid touching an unknown plant until it has been clearly identified.

What can it do?

All parts of the plant, including the roots, contain the poisonous resin urushiol. Most people develop symptoms 24 to 48 hours after contact. The extent of a reaction depends on the individual's sensitivity and the amount of sap in contact with the skin. The inflamed areas frequently develop blisters which are accompanied by intense itchiness. Contact with any broken part of the plant may cause a reaction in some individuals. The rash spreads by exposure to the sap and not from the sores themselves. Therefore, an individual has to actually come into contact with the sap, but not necessarily with the plant, before developing an allergic reaction. Contact with a surface that has picked up sap from the plant, for example the fur of an animal, can also result in a reaction.

If poison ivy is burned and the smoke then inhaled, this rash will appear on the lining of the lungs, causing extreme pain and possibly fatal respiratory difficulty. If poison ivy is eaten, the digestive tract, airway, kidneys or other organs can be damaged.

How can I manage it?

Protective Clothing

When working in or near poison ivy, always wear gloves and protective clothing to ensure that no area of the skin is exposed to the sap of the plant. Poison ivy sap can adhere for long periods to clothing, tools, and the hair coats of pets and livestock. Under hot, humid conditions the sap becomes inactive in about a week. Under dry conditions, it can retain its harmful effect for as long as one year or more. Any clothing worn while working in or near poison ivy should be carefully removed, washed in hot, soapy water, and hung outside to dry for several days. Remember to wear gloves while handling objects that may be contaminated. Do not wash clothing suspected of contamination with other laundry in order to avoid any further contamination. Repeated washing may be necessary.

Skin Contact

Areas of skin that are suspected of contamination should be carefully washed with soap and cold water. Cold water should be used because hot water tends to open the pores of the epidermal layer; the heat would increase the chances of the resin being deeply absorbed into the skin. If soap is not available, vinegar (2 tablespoons in 1 cup of water) or alcohol (1/2 cup to 1/2 cup of water) can be substituted. It is important to note that these practices may not prevent a reaction, but will likely prevent the infection from spreading. If a reaction does develop, one should seek the advice of a physician for proper treatment. Skin irritation (itching, red inflammation, blistering of the skin and, in severe cases, oozing sores) resulting from exposure to poison ivy normally disappear in 7 to 15 days.

Cultivation

Pay particular attention when clearing dead vegetation in early spring or late fall to recognize and carefully handle any poison ivy plant material. For effective control of poison ivy, the reproductive capacities of the plant can be disrupted by destroying its roots and stems. By digging out and hand picking the roots and stems, and working the soil frequently, the ability of the plant to produce shoots will be minimized. Repeated cultivation will eventually eliminate poison ivy because the plant does not regenerate easily from plant fragments. Since loose seeds may be difficult to detect, remove any dead plant material from the ground in case some seeds are still attached to the stems.

Products

Applying herbicides to control poison ivy can be effective. One single treatment may be enough, though it is possible for re-growth to occur particularly where treated plants have been growing for two years or more. It may be necessary to repeat the treatment as often as re-growth appears. Applying herbicides by spot-treatment will help to minimize the chances of the product drifting onto other plants. Herbicide spot treatment is also advisable when poison ivy is a lawn weed.

Domestic class products available to homeowners for the control of poison ivy will usually contain one or more of the following active ingredients: amitrole, simazine, glyphosate, 2,4-D, mecoprop, or dicamba. Domestic pesticides can usually be purchased through garden centres or hardware stores. Purchase only those products whose labels indicate poison ivy control.

Disposal of Poison Ivy

Do not burn poison ivy. This may release the poison in the form of tiny droplets carried by the ash and dust particles in the smoke. A severe reaction may occur if a sensitive person inhales or is exposed to this smoke.

Dead poison ivy plants can still cause dermatitis and must be handled with care since the urushiol oil can stay active on any surface for up to 5 years. Dispose of them by placing them in a garbage bag. Make sure that bags containing poison ivy are sealed, well identified and disposed of with household garbage.