Note: A different version of this post originally ran on May 18, 2010. Several people have recently told me they don't know how to identify poison ivy, so I thought rerunning this might be useful.
I'm super allergic to poison ivy (sometimes I swear I get it just by looking at it) so I taught myself how to identify it in every season.
Today, I offer these photos to help my New England readers avoid poison ivy. This is what poison ivy looks like now.
Notice the differences in the color and size of the leaves. Poison Ivy can look very different even in the same area. All of these photos were taken within roughly 1/4 mile of my house.
One thing that is consistent is the presence of three leaves in a cluster. Usually those leaves are shiny. Sometimes those leaves are mostly green.
Other times the leaves are more red. (Especially when they are first sprouting in the spring).
Sometimes it grows low to the ground like in the photos above. Other times it climbs up posts, signs, and trees as in these photos:
This one is about 3 feet tall.
This one climbs about 20 feet into the tree.
These last two photos are NOT poison ivy. This vine is sometimes confused with Poison ivy because it climbs the same way and has similar shaped leaves.
But look closely... there are 5 leaves in each cluster and the leaves are more jagged.
One final tip: poison ivy thrives along the edges. That is, in the area where one ecosystem transitions to another. For example, some of these photos were taken along the edge of a field where it transitions into forest (in partial to full sun), others along the edge of a brook (in partial sun), still others along the edge of a road (in full shade). Also watch for it along the edges of parks, paths, or trails.
Do you know how to identify Poison Ivy? Do you have any other tips?