If this is your rookie season in the garden, there are a few things that are good to learn to prevent injury from exposure to plants that carry rash-causing resins. It is helpful to know what poison ivy, poison oak, and poison sumac, look like. All three of these plants can cause rashes if contact is made with the leaves and/or resins. Inadvertent contact with these plants has stopped many a gardener-in-the-making and confounds many others season to season. There are procedures recommended by the medical community to wash both skin and clothing ASAP but it is also prudent to wash work gloves and tools that may have come in contact. The rashes can range from mild nuisance of small oozing blisters, requiring calamine lotion to dry it up, to large oozing painful blisters, requiring medical treatment. It takes 7 days after exposure for the rash to appear which can be a long enough to forget that you may have picked it up from the garden.
For poison ivy and poison oak, there is a cute little saying, “Leaves of three, let it be.” It is a great saying but it is not really useful because in the learning stage lots of plants look like they have three leaves on a stem. All three of these poison plants are so benign looking, without major distinguishing traits, that they are easy to miss, hiding in plain sight. A good ID website for these plants is www.poison-ivy.org. The pictures on this website show the variations in the leaf shapes, the colors of the leaves season to season how they can go from dull to shiny. They also have gross looking pictures of the rashes, if you dare.
Notice how variable the poison ivy leaves can look, sometimes like an oval and some with a mitten shape with a bump like a mitten's thumb. How helpful is that? (tongue in cheek) Poison ivy leaves can also be shiny and other leaves can be un-shiny. They can be growing along the ground or along vines up a tree. I bet that is helpful?!?!?! (tongue in cheek). Some of the leaf margins have small teeth while others are very jagged. The best way to find poison ivy is to train your eye to really look for it. Look past the perennials in the garden and along paths as you walk. The more you look for it the better your chances are to really see it.
Poison ivy is the most common of the three to find. It grows pretty much everywhere along the eastern seaboard and heading west. Poison Sumac, while also tricky to identify, is a bit easier to avoid. There are many different varieties of Sumac, to my knowledge only one of them is poisonous and is found in marshy, swampy areas. The internet is a handy tool for cursory identification of plants, pictures abound, but misinformation abounds too, so use it to assist with identification but always get confirmation from sources ending in .edu or .org or USDA, university, or Cooperative Extension resources out in the field. If you are unsure about a plant, take a photo, and take it to the local garden center expert or agricultural extension office for confirmation. Or take it to both, once to get identification and a second for confirmation. You can also start with the www.poison-ivy.org since their information seems to be on target and the pictures show lots of examples of these misty maidens.
The best defense with these plants is a good offense. Assume poison ivy is there until you know for a fact that it isn't. Wear long pants, long sleeved shirts and gloves and make sure all are washed including the tools at the end of the day. There are topical cremes that can be used before possible exposure. I have contracted the rash many times over the years and made sure I started treating it with calamine lotion right away. I am not highly allergic to it and the lotion works well in drying the rash up. If you notice the rash spreading make sure you seek medical attention immediately. The good news is the more you look for it the more you will see it and the better you will get at avoiding it. But most importantly, do not let it stop you from conquering and reclaiming your yard.