Nothing takes the fun out of being outdoors faster than an encounter with poison ivy. It's the cockroach of the plant world: it regenerates readily, it's everywhere, and people loathe it. At least one member of the poison ivy clan (Toxicodendron, formerly Rhus) grows in every state in the continental U.S. Each region has its own varieties of poison ivy or poison oak, but all are perennials in the cashew family, and all cause a rash, blisters, and that unquellable itch. Our guide helps you to identify, search out, and destroy the culprits in their hiding places, and to beat the rap?—uh, rash—even before it strikes.
Poison ivy in summer
"Leaves of three, let them be" is still the best way to identify poison ivy and poison oak. Poison ivy's leaves are pointed.
Poison ivy in fall
Both poison ivy and poison oak grow in sun or shade, in wet or dry places, and turn vivid colors in fall
Poison ivy in winter
The berries are white and are a good identifier once the leaves have fallen off in early winter.
Poison ivy in spring
Poison ivy can grow as a groundcover, a shrub, or a vine. Emerging leaves have a red tint to their edges.
Poison oak's leaflets are rounded. It grows as a vine or shrub.
Poison ivy root
Both poison ivy and poison oak climb trees, sending out thick, hairy, aerial roots.
This native (and harmless) vine is often mistaken for poison ivy, but Virginia creeper has five leaflets, and blue-black berries.
Other Itchy Suspects
Myrtle spurge, or donkey tail
(Euphorbia myrsinites) This ornamental contains a toxic, milky latex that can permanently scar the skin.
(Ruta graveolens) All parts contain a photochemical that causes a heightened reaction to sunlight (photosensitization).
(Centaurea maculosa) This biennial weed causes hives, usually with repeated exposure.
(Pastinaca sativa) Juice found in the leaves, stems, and fruits causes photosensitization.
Wear long sleeves, pants, closed shoes, thick gloves, and even a mask when removing poison ivy and poison oak.
- IvyBlock is an FDA-approved lotion that, when applied before exposure, prevents skin that comes in contact with urushiol from developing the rash. It's available at drugstores.
- Wash all clothes, even shoelaces (without touching them with your bare hands), after working near poison ivy and poison oak. Use hot water, detergent, and two wash cycles.
- Wipe down any surface that has come in contact with the oil (tool handles, doorknobs, shoes, etc.).
- Your pets aren't sensitive to urushiol, but if it gets on their fur and you pet them, you can get a rash.
Already a Victim? Fight Back
Wash it away. Do not wipe with water—urushiol is an oil, so it does not dissolve in water. Rinse the affected skin with isopropyl (rubbing) alcohol, then with cold water. Don't wipe. Wiping spreads the oil.
Over-the-counter topicals such as Tecnu, Ivy Complete, Zanfel, or Burt's Bees Poison Ivy Soap and Res-Q Ointment also remove the oil and relieve itching. Without treatment, the infected area will blister within a few hours to three days. The fluid in the blisters will not spread the rash, but any clothing that has come into contact with the oil will. Oral antihistamines can help, if needed.
Dispatch the Enemy
Poison ivy and poison oak spread by seed and by their vigorous root systems. They arrive in your yard by birds eating the berries and depositing the seeds, and, less frequently, in loads of mulch. If you have wooded or neglected areas surrounding your property, you probably have poison ivy as a neighbor, and given time, it will creep into your yard. Five ways to beat this foe into submission:
1. Keep it out. Prevent poison ivy or poison oak from taking hold in the first place. If you are landscaping or tilling soil for a new bed or garden, don't leave the ground bare for long.
2. Target seedlings. Small infestations are more easily controlled than larger ones, because they have less-developed root systems, fewer stored food reserves in roots and rhizomes, and a smaller seed bank in the soil. Poison ivy can be readily pulled in early spring if only a few plants are involved. Look for those leaves of three, and, wearing long sleeves, long pants, and thick gloves, pull out the entire root system.
3. Cut it off. As with all perennials, you must completely remove the root or the plant will resprout. Unfortunately, poison ivy roots can run underground for many feet before the plant reappears above ground. If endless digging is not appealing or an option, repeatedly cutting the plant to the ground eventually starves the root system and causes the plant to die. Plants climbing trees should be severed at the base. Don't bother removing the vines from the tree; they don't do any harm, says Ray Samulis, county agricultural agent at Rutgers Cooperative Research and Extension. The weed is just using the tree for anchorage. It's not a parasitic relation- ship, says Samulis.
4. Smother it. Cover the infested area with thick black plastic sheeting, and plan to leave it there for at least a year, possibly longer. Make sure the plastic isn't the type that degrades in the sun, and cover the edges with dirt to exclude all light.
5. Chew it up. Grazing animals, especially goats, are not bothered by urushiol and can clean up an infested area. They won't take out the root system but will get rid of the topgrowth, weakening the plant overall.
Ditch the Evidence
Do plasticize it. Dispose of poison ivy and poison oak in plastic bags and put them out with the trash. The easiest way to do this is to put the plastic bags over your gloved hands, pull the plants into the bags, and then pull the bags inside out off your gloved hands, encasing the poison ivy inside the bag. Be nice to your garbage man and put the poison-ivy-filled bags into a larger, uncontaminated bag.
Don't compost it. Urushiol remains potent for years—even, in dry climates, decades.
Never burn it. Breathing in smoke or soot from the plants may cause serious inflammation of respiratory mucous membranes.