What to look for. All are easy to spot, Laverne said. Poison ivy has three leaflets on short stalks. Leaf edges often have a notched edge. Poison ivy grows both as a ground cover or a climbing vine. You often find it along edges of woods or fence lines. It's most common in the Southeast, the Midwest, and as far north as Michigan.
Poison oak grows in the Southeast and the West, but not much farther north than Kentucky. It's a shrub, between 1 and 3 feet tall. Its leaves also come in threes, but have deeper lobes so resemble red oak leaves. Sumac, the most toxic, is common in the east up to Canada. It grows as a shrub or small tree, with seven to11, oval, deep green leaflets per stem.
• Wear a barrier. If you're not sure whether these poisonous plants are in your yard, assume they are, and when working outside, wear gloves, long sleeves, long pants, a hat and closed shoes.
• If exposed, break out the alcohol. No, not to drink, to douse exposed areas. Hit exposed areas with rubbing alcohol fast, inside 30 minutes, if possible. Intervene before the oil binds with skin cells. Then rinse with clear water, and shower (don't bathe) using warm water and soap.
• Wash clothes and tools, too. Urushiol can stay on clothing, shoes, gloves, and tools for years. Wash exposed clothing apart from other clothes. Hose off tools and shoes right away.
• Beware of dog. Though animals don't react to poison plants like humans, Fido or Fifi can drag the oils into the house on their fur. If you pet them, you could get a reaction.
• Never burn. Don't burn yard debris if you suspect any plants are toxic. Anyone who inhales the smoke could land in the hospital.
• Spray it away. To rid your yard of poison plants, spray the foliage with weed killer, like Round-Up, and let the plants die, roots and all, Laverne said. (Don't pull them out.) If you still want to remove the dead plant, wait until winter when the least amount of oil will be present.
• If you get a reaction. Try over-the-counter remedies like Benadryl, Calamine, or hydrocortisone ointments to relieve itching. (I liked Tri-Calm.) If that isn't enough, see a doctor for something stronger.
Syndicated columnist and speaker Marni Jameson is the author of “House of Havoc” and “The House Always Wins” (Da Capo Press). Contact her through www.marnijameson.com.