"Leaves of 3, Let It Be"

In this article on About's Pediatrics site, we are reminded that about "85 percent of the population will develop an allergic reaction if exposed to poison ivy," which you can generally avoid if you remember the maxim, "Leaves of three, let it be!" while landscaping your yard. "Usually, people develop a sensitivity to poison ivy, oak or sumac only after several encounters with the plants, sometimes over many years."