As anyone knows who has learned the old saying “Leaves of three, let it be” the hard way, poison ivy has a nasty habit of rewarding those who touch it with two or three weeks of blistering misery.
Poison Ivy's “leaves of three” are glossy-green, but are tinged with pink in the spring, and take on a brilliant orange in the autumn.
It has small, pearl-colored berries. These are a favorite treat of many birds, which spread poison ivy seeds around the countryside.
The poison is an oily resin called urushiol that occupies every part of the plant, including the roots.
The leaves, especially young ones, contain the most toxin.
The oil can remain on tool handles and clothing for as long as a year. Dogs and cats can carry its potency on their fur. This is why you can come down with a rash without having seen poison ivy in months.
Fortunately, the oils don’t always go to work immediately, especially on dirty or work-hardened hands. If you come in contact with poison ivy, wash up at once and launder your clothes using old yellow laundry soap or boraxo to cut the oil. (Soaps made with fat are ineffective.)
If you become affected, there is no shortage of remedies, but many of them are useless and some can even make matters worse.
Mild cases can be helped by calamine lotion, over-the-counter cortisone creams, and saltwater soaks, but severe cases require prescription cortisone.
A barrier cream, IvyBlock, containing quaternium-18 bentonite, which bonds with the urushiol, promises to be effective 68%of the time, if applied before any contact with poison ivy.
Eradicating poison ivy is probably the best way to remain itch-free. The plants can be destroyed by covering them with black plastic or spraying them with appropriate herbicides. But beware—even dead plants are infectious.
Perhaps someday, plant scientists will develop a non-poisonous variety. Rumor has it that they have already crossed poison ivy with four-leaf clovers, hoping to get a rash of good luck.