Written by s • How To Kill Poison Ivy

Poison Ivy was here when the first settlers arrived, but it with suburban development it has become much more wide-spread, since it lives naturally at the edges of woodlands, just where we tend to build new developments. This perennial plant, which takes many forms, from ground-hugging bush to climbing vine, is a scourge, hurting adults, children and pets and causing severe reactions in sensitive people. About 15% of people have no reaction, luckily children under five can also often not react, but like all allergies, exposure can easily lead to future reactions, so no-one is really immune for life.

Poison Ivy contains a chemical – Urushiol – which is an oil that quickly dries and is easily transferred from one place to another, whether it’s skin, clothing, door-handles or tools. It is this feature that makes it such a problem.

Is it Really Poison Ivy?

Because many people worry about poison-ivy, lots of plants get mistaken for it, so the first step, if you spot something suspicious, is to make sure it really is Poison Ivy.

The old, leaves of three, let it be, is a good start, but other plants also have three leaves. Since this is a variable plant, the following group of indicators should all be present to be sure you have a real problem. Of course, don’t pick a bit to check – treat this plant with respect!

The leaf is usually smooth edged or only slightly toothed
The leaf surface is somewhat glossy
The leaves are in clusters of three leaflets, each on a long stalk and growing as a group on their own stem and connected to the main plant
The leaves alternate along the stems, that is, they are not paired on opposite sides of the stem
The plant has no thorns

If your plant has all these characteristics, you have poison ivy. As well, you may see clusters of small green flowers or white berries, lower down on the stems.

Ways Not to Get Rid of Poison Ivy

Whatever you choose to do, avoid the following ‘ideas’, which won’t work and can even kill you.

Don’t set fire to it – the smoke is extremely toxic and can kill you

Don’t mow it down This will just spray the poison all over the place, including you and the mower, so every time you mow the lawn you will get more rashes.

Don’t just grab a spade and dig it out – again you will just get it all over your tools and clothes and spread the problem further. Anyway, it has deep roots that persist and are hard to remove.

How to Kill Poison Ivy

There are two possible approaches, the organic method and the chemical method.

The Chemical Method – Poison Ivy is susceptible to the chemical weed-killer glyphosate, sold as Round-Up. Even in some areas where chemicals are banned for home use, you can still buy this product to control Poison Ivy. It is also susceptible to triclopyr, sold as Brush-B-Gon. Remember that both these products will kill every plant they touch, so only spray in a controlled way directly onto the leaves of the Poison Ivy. Follow the manufacturer’s directions carefully and use a dedicated sprayer for this job – don’t use it for regular pest-control products afterwards or you may kill your plants with the residues in the spayer.

The leaves and stems will die in a couple of weeks or so after spraying. Keep some spray handy, as you will probably get re-growth unless it is just a small plant. Spray any re-growth as soon as you see it and keep doing that until nothing more is growing. It may take two or three follow-up sprayings to completely eradicate the plants. Once it has all rotted down the area can be cleared and planted, but dying plants will still contain the poison, so wait a couple of months at least, till there is nothing left to see.

The Organic Method – the simplest way is to spray boiling water on the plant. Of course this will damage any surrounding plants too, so be careful. This will kill the top-growth, but it will quickly re-sprout and many, many applications may be necessary to eliminate a large patch. This is really only practical for a few seedlings.

A more thorough result can come from weeding it out, but this is very tricky. If the plant is growing up a tree, saw through the base of the trunk and leave it a few weeks to thoroughly die. Wash the saw in cold water and rinse in vinegar. For plants on the ground you will have to handle live material.

The day before you start, water the area thoroughly to soften the soil. Dress in old clothes, covering your arms, neck, and tucking your trousers into your socks. Wear washable shoes.

Get some heavy-duty large plastic shopping bags –the ones from expensive stores – and put one over your pulling hand. Regular thin bags may tear and let the poison through. With your hand inside the bag, pull up the plants, trying to get as much root as possible and transfer the pulled plants to deep inside another bag. Having someone help you is worthwhile. Never touch your face for a moment while you do this.

Once you have it all bagged up, get your helper to open all the doors in your house, go straight to the bathroom and have them open the washing machine door. Put all your clothes and shoes in and turn on a cold wash cycle. Now get them to open the shower door and get in, taking a shower with no soap. The poison dissolves in soap and will spread onto sensitive parts of your body! Then take a normal shower.

The next day, repeat the whole process, using a spade this time to dig up as many root pieces as you can. You will probably need to repeat this process as soon as you see any new pieces sprouting, until nothing new grows back, which could take several attempts.

You can see why even dedicated organic gardeners resort to chemicals when it comes to poison ivy!

Good luck with eliminating this vicious plant – and take care!

Comments 4 comments

October 10, 2018 by Larry Corder

I have a plant that looks like poison oak but the 18-inch stem has thorns. Is this plant poisonous?

October 10, 2018 by G Dave

Hard to identify accurately based on your brief description, but if it has thorns I would take a guess and say blackberry. if it has white flowers in spring, and green berries that turn red and then black, that is what it is. Harmless but weedy, but don’t take chances. Try taking a picture to a local garden center or garden club meeting.

August 27, 2019 by Doug B

There are different varieties of poison ivy? Some match the description and picture on this site, many don’t. An image search online will demonstrate the wide variation.

* In our woods in Michigan (other places in our state are different) the leaves sometimes have deep and sometimes shallow cuts. (Other varieties match your site’s description as smooth edged.)
* In our woods the surface has no gloss whatsoever. (Though I know some varieties match your description as somewhat glossy.)
* Our variety climbs trees though some varieties in some ranges do not.
* All have the three leaves.

Why are there so many varieties of poison ivy?! Heck, I don’t know. Probably the same reason there are so many varieties of oak trees, roses, dandelions or any other plant.

I could not tell from your site where you are located.
I advise anyone wanting to identify poison ivy to do an image search online.
I wish there were a site that showed all the varieties side by side including having maps showing the ranges where each grows.

August 27, 2019 by Dave G

Gardeners easily make the mistake of thinking plants of the same species are very similar. This is because many of our garden plants, like the roses you mention, for example, are clones – identical genetic copies of the same plant. Wild plants are not like that. Although in a local area a clone may cover a lot of ground, general each plant is genetically unique, originating from seed. This means that wild species are a lot more variable, one individual to another, than we see in garden plants. Although it is true that Toxicodendron radicans, as botanist call poison ivy, has several subspecies, with distinct differences. they are confined to small areas, mostly outside the USA (Mexico for example). You can see some maps here.
So it is hard to give a clear description of poison ivy, because it does vary, and you need some training in plant identification to be reasonably sure you have it right. This is of course a problem when all you want to do is get rid of it, and avoid coming in contact! Many of the images on-line are not even the right plant, so I wouldn’t put too much store by them either. Botanical sites will be better, but they will not show you exactly what plants around you might look like. You are right about the climbing – some do and some don’t. There is also a different species (T. diversilobum) out West. Sorry, Nature is always cooperative in our wishes to learn more about it!