Leaves distinguish between poison ivy, Virginia creeper
Many of us are spending more time out of doors this summer, and perhaps some of that time has been spent exploring natural areas for hiking, bicycling, or fishing. During these outdoor excursions, you may encounter vines growing alongside trails and stream banks.
How can you determine if these vines are the notorious poison ivy or the innocuous Virginia creeper?
Poison ivy (Toxicodendron radicans) is a native species primarily found along open edges of a variety of habitats including wooded areas, fields, thickets, fence rows, trails and disturbed areas.
Poison ivy often grows as a vine. However, it may grow as a small shrub, as a single-stem plant, or clump of plants.
As a vine, poison ivy climbs with visibly hairy roots. It flowers in late spring and early summer and produces clusters of white berries. The leaves are always comprised of three leaflets. The middle leaflet may be slightly longer than the others.
Apart from always having three leaflets, the leaves of poison ivy are highly variable in form and can be shiny or dull; hairy or not; and with edges that are smooth, wavy or coarsely notched.
New leaf growth in the spring is generally reddish and as they grow become larger and dark green. In the fall, they turn red, yellow, and orange.
Urushiol is the oil within the plant that causes the allergic reaction. Many people are not allergic to poison ivy on their first encounter. However, after repeated exposures, they develop an adverse reaction.
All parts of poison ivy are poisonous and remain so even after the plant is dead. Unlike humans, many wildlife species are not allergic to poison ivy, and many bird species rely on the berries for food in fall and winter.If you have poison ivy on your property where it is likely to be in contact with you, family members or pets, it can be removed with a broadleaf herbicide. If there are only a few stems, dig out the offending plant. Repeatedly cutting the plants will also control poison ivy.Never burn the cuttings of poison ivy because the smoke will contain urushiol and, if inhaled, may cause an allergic reaction in the lungs. Do not use a motorized weed trimmer to eliminate poison ivy because the forceful trimming spreads the oil to your clothing, boots and exposed skin.Leave poison ivy undisturbed if there is no risk of contact with its leaves because this native is an important food source for wintering birds.Wash garden gloves and clothing in hot, soapy water after touching poison ivy, and wash exposed skin thoroughly. Dispose of poison ivy in bags in the trash can, as poison ivy cannot be composted.In the same settings you encounter poison ivy, you may find a similar looking vine called the Virginia creeper (Parthenocissus quinquefolia).Poison ivy and Virginia creeper may look alike, but the most obvious distinction is that Virginia creeper possesses leaves consisting of five leaflets. These leaflets have a toothed edge and are consistent in form.Virginia creeper climbs or trails on the ground using tendrils with adhesive ends called sucker discs that allow the tendril to adhere to the bark or other surfaces as opposed to the hairy roots of poison ivy vine. On the ground, it forms a ground cover about a foot high.After blooming in the late spring or early summer, Virginia creeper produces dark blue berries that are also of value as a food for a variety of wildlife and birds.
Virginia creeper can grow on trellises, arbors, or chain link fences, and it can be grown to cover tree stumps, rock piles, or other eyesores. The leaves become a brilliant red color in the fall and can be a fabulous addition to your landscape.However, Virginia creeper can be aggressive, so plant it in a location where it can be controlled.Poison ivy and Virginia creeper offer food and beauty to the environment. To remember and distinguish between poison ivy and Virginia creeper, remember this — “Leaves of three, let it be; leaves of five, let it thrive!”Butler County Master Gardeners can be contacted through the Butler County Extension Office at 724-287-4761 or you can submit your question along with your name, address and telephone number to Master Gardener, c/o Penn State Extension, 101 Motor Pool Way, Butler, PA 16001. Email inquiries can be sent to Butlermg@psu.edu.Mary Alice Koeneke is a Penn State Master Gardener of Butler County.
