"Leaves of 3, let them be." This rhyme works for both poison ivy (Rhus radicans) identification and poison oak (Rhus diversilobum) identification. The rhyme does not, however, work for poison sumac identification (that is, the shrub, Rhus vernix). But people are more likely to be plagued with the other two types of Rhus than with R. vernix and will thus be more interested in learning how to get rid of those.
There are also non-poison sumacs, such as R. glabra. The Rhus genus is native to North America.
In the U.S., poison ivy grows everywhere but on the West Coast, while another vine (sometimes shrub), poison oak grows primarily on the West Coast. In plant taxonomy, all three are sometimes classified as Toxicodendron rather than Rhus ("Toxicodendron" is from the Greek and literally means "poison tree"). This article deals mainly with Rhus radicans, but most of the facts related here also pertain to poison oak and sumac (especially to the former).
The trademark grouping of three leaflets on Rhus radicans has a reddish tinge when the leaves first come out in the spring, but the leaves turn green in the summer. Although the color (white) of its berries is often mentioned as a method for poison ivy identification, it is not as reliable as is identification by leaf. The berries, after all, are produced only at the end of the growing season.
Knowing about the berries would do you little good when attempting identification in the spring, for example. Poison oak and poison sumac also have white berries. The non-poisonous varieties of sumac have red berries.
Who's Afraid of Virginia Creeper?
In the eastern U.S., another wild vine flourishes that is often mistaken for Rhus radicans: Virginia creeper (Parthenocissus quinquefolia).
But Virginia creeper more often has five leaves to a stem rather than three. Its leaves are also more toothed at the edges than are the leaves on Rhus radicans. The fall foliage of this vigorous grower is truly spectacular.
While Virginia creeper vines do not contain urushiol oil, the compound that makes Rhus radicans toxic, you may need to shun contact with Virginia creeper, too. It turns out that the Virginia creeper's sap contains oxalate crystals, which can be toxic to some people. If you're unsure as to whether you're one of those people, don't touch Virginia creepers, since the result of contact could be a skin rash.
Like Virginia creeper, the fall foliage of Rhus radicans is surprisingly spectacular. One is tempted to ask, How can something that has caused so much suffering be so beautiful? The green summer color of the plant's leaves yields to brilliant fall foliage in red, yellow, or orange. Their autumn brilliance is due to the anthocyanin pigments characteristic of the plant family to which they belong, namely, the cashew family.
But if you're reading this article while plagued with the itching that the plant brings, you'll be much more interested in hearing some treatment tips than about how pretty the plant looks in the fall.
Treating Poison Ivy Rash With Natural, Home Remedies: Jewelweed
Now that we've identified the plants in question, let's consider the matter of treating poison sumac, poison oak, and poison ivy rash (treatment will be the same for all three). When we speak of a cure or treatment for this rash, we generally mean relief from its symptoms, primarily the itching.
Different people find different degrees of relief by treating poison ivy rash with over-the-counter remedies, such as hydrocortisones. Despite its inclusion in the classic rock song, "Poison Ivy," even Calamine lotion has its limitations as a treatment.
Some people have such a severe reaction to poison ivy that they need to visit a physician and get a shot. It usually takes about two weeks to get rid of poison ivy rash. For a home remedy, try applying the crushed leaves of jewelweed (Impatiens capensis).
The beauty of this home remedy is that jewelweed is a common weed in damp areas. This "treatment" may very well be growing right in your own backyard.
But there is another kind of treatment of poison ivy rash: namely, prevention. If you realize you've just come into contact with poison ivy, apply rubbing alcohol to the infected area and/or rinse with water (any water).
So what makes poison ivy (and poison oak and poison sumac, too)...well, poisonous? The answer is urushiol, which is the sap that runs through all parts of the plant. Grazing against poison ivy with any exposed part of your body is all that it takes to release this poison. Complicating matters further, contact with poison ivy does not even have to be direct for you to contract the rash. For instance, if your dog runs through some poison ivy, then you stroke your dog's fur with your hand, you could come into contact with the sap and develop a rash. Likewise, if someone else had been working in a poison ivy-infested area with gloves, then you came along and touched those contaminated gloves, you could get the rash.
So if the poison is spread that easily, poison ivy must be contagious, right? Wrong. It's only the urushiol that puts you at risk. Scratching your bumps doesn't cause the poison ivy to spread to other areas of your body. Nor will you contract the rash just by touching somebody else's rash bumps. Once the bumps are present, the damage that the urushiol can inflict has already been inflicted.
Now that you know how easy it is to contract the poison ivy itch, what you probably really want to know is how to get rid of the poison ivy growing on your landscape.
How to Get Rid of Poison Ivy, Oak
Now it's time to consider various methods to get rid of poison ivy plants, themselves, where they grow in your yard. Follow the same steps to kill poison oak. The first question to ask is how to remove poison ivy safely.
Indeed, a word caution is in order, before discussing any actions to be taken to get rid of poison ivy in your landscape.
When approaching the itchy weed to engage it in battle, try to have as little of your skin exposed as possible, since it is through physical contact with poison ivy (all parts of it, including the roots) that the rash is contracted. At the very least, this means wearing gloves, long-sleeved shirt, and full-length pants. Secondly, understand that any of the removal methods discussed below may have to be done more than once to achieve complete success.
One organic method used to get rid of poison ivy is to pull it out by the roots. The roots must be disposed of; do not burn! Inhaling fumes from burning poison ivy causes far greater health problems than just the rash caused by skin contact. Another natural removal method is smothering. Smothering entails cutting the plants back close to the ground, then placing newspapers, cardboard, old carpeting, tarps, mulch or some other covering on top. However, be aware that, even after you kill poison ivy plants, they remain toxic. So be careful in disposing of the roots of the dead vines after pulling back the smothering agent (even if you've waited for years).
Herbicides can also be used to get rid of poison ivy. Roundup spray is a popular but controversial glyphosate-based herbicide used to kill it. Another widely-available herbicide is Ortho Brush-B-Gon, which is triclopyr-based. These products will kill a great variety of woody plants, making them effective not only in getting rid of poison ivy and poison sumac, but also another nuisance vine: Oriental bittersweet. But they will kill many other plants, too, so don't use them near specimens you wish to keep. If you choose to apply these herbicides by spraying, here's what to do:
- You'll need a pressurized tank sprayer. Mix the herbicide with water, according to directions.
- Apply when the poison ivy is fully leafed out.
- Pick a day with little or no wind for spraying. Also, check your forecast: Don't spray if rain is predicted at any time within the next 24 hours.
- For poison ivy plants growing on the ground or on a wall, heavily spray the leaves and branches of the vines. Older plants have large, hairy vines. Remember this fact to identify poison ivy in winter, when no foliage is present (rendering the "Leaves of three, let it be" rhyme useless).
- For poison ivy climbing up a tree, you may wish to "paint" the herbicide on, so as to avoid damaging the tree with a stray mist from your sprayer.