Poison ivy is one plant you don't want to get too close to.
"Leaves of three let it be," said Peter Carrington, repeating an old adage.
It's advice that Carrington, assistant curator of the WJ Beal Botanical Garden at MSU, says is more important this summer.
Spring rains create the perfect growing environment for poison ivy and this year we've had plenty.
"Any kind of mild, wet, moist conditions are excellent for growth," Carrington explained. "So we would expect this to be an excellent growth year for poison ivy."
But that's not the only thing fueling the plant's growth.
Carrington says increased amounts of carbon dioxide in the air are creating heartier strains of poison ivy.
"Plants that have the increased growth rate from carbon dioxide, also have increased potency," Carrington said.
Almost 85 percent of people are sensitive to poison ivy, so doctors advise anyone venturing outside to use extra caution.
"Look for the plants, know what they look like and try to avoid them," said Dr. Edward Rosick, chairman of the Family & Community Medicine Department at MSU.
It's not just what you're walking on that you need to be careful of. Poison ivy can grow up trees and shrubs so doctors say you should always be aware of your surroundings.
The plant's oil is what causes an allergic reaction, so if they's any chance you came into contact with it Dr. Rosick says you need to be vigilant.
"As soon as you get that oil on your skin the sooner you can wash it off the less of a chance you'll develop severe symptoms," he added.
But the best way to avoid all the itching and scratching is prevention.
"If you have any doubt in your mind don't touch it because if you touch it and it is poison ivy then you're sort of out of luck," Rosick said.