How to kill Poison Oak and Poison Ivy

by admin on May 17, 2008 · 34 Comments

in advice, All Posts, Pests & Weeds, Problems and Solutions

Poison Ivy

Western Poison Oak in Fall color

Poison Ivy is one of the worst enemies to gardeners and hikers. In the drier western states, its rude cousin Poison Oak is just as bad. The techniques for eradication of Poison Oak and Poison Ivy are the same are.

You basically have two options, one mechanical and one chemical. The mechanical is friendlier to the environment but the chemical is easier on humans, you make the call what is better for you.

To mechanically eradicate the plant you have to kill the roots. You can trace the vine back to its crown and dig it out with a shovel or you can use pruning equipment to cut the stems back to the ground. This will take repeated attempts as the roots will send up new shoots time and time again, so you will have to be persistent.

To chemically eradicate the plant you must apply a chemical to the leaves. It must be the type of chemical that is systemic and will be sucked down to the roots. If you use a chemical that only kills the leaves the plant will re-sprout. The chemical ‘Round-up’ (glophosate) works best from my experience but I hear Amitrol also works well. This too will probably take repeated sprayings as the plant will attempt to re-grow. The spray must be applied when the plants are actively growing and not when they are dormant in the winter. The best time I have found is late summer/ early fall when the plant is pulling down nutrients to the root system in anticipation of winter.

If you decide to go the mechanical route please be careful and wear protective clothing, preferably disposable. The poison is oil based so if you get it on your skin, lather up with soap quickly. Warm water tends to spread the oil so cold water with soap is best.

My friend Tim “Smiling Cat” Eutin sent the following question to my blog.

  1. Hello Rees,
    I just came in from mowing the lawn and was thinking about you. Why? You are very knowledgeable and come across as “real” and trust worthy. Here’s my problem…

I moved into an older home that has a large hedge. The hedge is a mix of 31 different plants, trees and vines. It doesn’t look as bad as it sounds as long as I keep it trimmed. (definitely not bad enough to go through the effort of removing it – that can wait for the next owner!)

Anyway the hedge has poison ivy in it. How can I get rid of the poison ivy without killing the hedge?


In your case SC, if the hedge can not be sacrificed then I suggest you suit up and go at it with chemicals. If you are careful, you may be able to untwine the vines from parts of the hedge and apply Round-up. If it is difficult to untangle just do the best you can. I suggest you use a paint brush or tiny sprayer to apply the chemical. This will take persistence and you will probably need to repeat but it can be done. I’ve used a similar method to kill spreading morning glory in a bed of junipers.

Whatever you do never burn the dead plants as the smoke will move the poison into your lungs….and that’s bad.

One last thing, make sure it is Poison Oak or Poison Ivey that you have. Fragrant Sumac and Virginia creeper have some similarities. Do a Google image search to be sure.

Good Luck!

Rees Cowden


This is the one and only situation where I will use roundup.



Have you ever heard of taking one of the branches and making a cut into it then placing that open wounded cut into a bucket of round up. It will feed to the roots and kill the whole plant. Much care must be taken to protect the area from pets and children. the cutting must be left in the round up for several days for it to feed into the root system to kill the whole plant. Kudzu is killed this way also. I’ve only read about this. I’ve never tried it.


My problem is that the poison oak is growing off of the tree its not rooted from the ground and it continues up the entire tree. I have children and a dog that I constantly have to keep away from that area. what the best way to get rid of this problem? Should I have the tree cut down?

Tim Eutin

Thanks for the advice. I’m suiting up and heading in. I’ll let you know how it turns out.


I actually have the same problem.. Has anyone ever tried the cut branch in a bucket suggestion, yet? -and if so, how did it turn out?

Rees Cowden

I appears I touched a note with this post.

Anna and Bek, I have my doubts that sticking a cut branch or cane directly into Round-up and having it translocated to the roots will work. It goes against my understanding about how xylem and phloem structures work but you never know. I have had people sware that cutting a girdling knotch around a tree trunk and pouring Round-up or Garlon directly into the wound will kill the tree. Again, I’m not buying it. If anyone has personal experience with either medhod please tell me about it.

Tim, I hope all went well and you didn’t need a trip to the doctors office.

Deb, I agree, the less chemicals we use the better.

Viv, sorry but that can’t happen. I bet if you checked closely around the trunk of the tree you would see a cane hugging the trunk. Poison oak must be rooted into the soil somewhere. you have the first poison oak tree !

Tim Eutin

Hello Rees,
Well the Round-up is working! The leaves are wilting and I hope that that is the end of the Poison Ivy! Thanks for your tips. I enjoy your blog.

Rees Cowden

I’m glad to hear it Tim. One caution though. Sometimes poison ivy or oak will trick you and look like they are dying. Watch for regrowth. After you see several leaves open spray it again. In most cases one attempt will not be enough.


Oh man, those things are horribly. Don’t ever burn the poison ivy, and in this situation I like to use Roundup also. And yea, they’re tough to kill.




Just a quick note on a natural and also eye pleasing way I have heard of to kill posion ivy if you like sunflowers. Buy some sunflower seed and spread it by hand in the area infested with posion ivy. Just toss a bunch in the area as you don’t want to go digging around the posion ivy. The sun flower from what I’ve been told sends a chemical into the ground to inhibit the growth of surrounding plants so that it can maximize the sunlight, i’ve seen this effect on beans in my garden where a sunflower came up. Only draw back is you will probably be left with a sunflower problem but to me thats better than the psion ivy.


I have poison ivy and poison oak on the trees and poison ivy all over the fence. How do i stop it?


Hey great info! I had problems with poison ivy last summer… wish I had this info back then…


Great info! I’ll have to try these tips to eradicate the ivy on our garage.


Hi, we have just bought a house near the beach and there is a poison ivy hedge along the front between the house and the beach. The hedge is ALL poison ivy and is about 10 feet wide, 30 feet long and 5 feet tall. I have battled PI in the past and lost badly so I:00fearful. Also, we have been warned that the PI root system protects the dunes. Would it be advisable to trim the PI hedge with a trimmer to keep it under control without damaging the dunes? Scout

Joanie Bock

how long does poison ivy and oak live after it’s cut from its root. Can you get poison ivy for the air or do you actually have to touch it/

Joanie Bock

How long do you wait to burn poison ivy after its been cut from its root.


I don’t think you EVER burn poison ivy, no matter how long it’s been since you cut it.


Hi Patty and Gail,
I’ve got a few poison oak stories to tell too but they don’t involve burning the debris. That sounds like it would be horrible….


Gayle is correct- NEVER burn poison oak! My grandparents did that and my mom and uncle were covered head to toe and in their mouths from the smoke. It was so bad they still tell the story 50 years later.


Years ago, in the Santa Cruz Mountains of Calif my brother and I raised goats. We tied up the nanny goat in a patch of poison oak, let her eat it, and drank her milk. We built up an immunity to the oak’s poison, and since we were woodcutters the time, it allowed us to tromp unafraid through the brush and woods. Now, 40 years later, I just bought a property that has oak on it, and I appreciate your methods of annihilation, because that’s exactly what I intend to do with it! But, if you own goats – let them annihilate it for you!


Solomon I think that takes the cake. I love goat cheese so how about if you make some goat cheese outta that milk and we sell it as a poison oak remedy…..
Thanks for the fun story…
PS I love the Santa Cruz Mountains.


Hi Sean,
I feel your pain. Poison Oak is no fun. DON’T SCRATCH IT!!!!!!
One thing you might try is to wait until fall and watch for the tips of the poison oak to begin turning red. It might be easier to find:00ong the other plants once it changes color and then try the selective Round-up method. Just done wait too long to stray after you see the first red leaf.
Other than that I guess you should just stock up on balls…..


We’ve got poison oak on our property… our yard ends right the start of a heavily wooded area. All around the ground is poison oak. And of course with children they are always throwing balls in there. I made the mistake of going into the woods to pick up some baseballs recently and:00now covered in itchy spots. Have had it before and know I need to go get a shot.

I’m leery of trying Roundup as there’s other vegation in the area and I don’t want to kill everything. But I also don’t want to buy a hazmat suit to have to cut it out.


We have a huge poison oak problem on our property, so much so that I keep my horses in a paddock rather then in our pasture. Then one year after a long winter I had an abundance of manure. Instead of taking it to the dump like usual we dropped it onto a severally poison oak covered section, and smothered it with two full truck loads.

Now that is one of the few places where poison oak doesn’t grow, and hasn’t for over three years. That small section now only grows tall grass. I think it has something to do with the horses diet of straight alfalfa, which causes livestock to have extremely potent urine that soaked into the manure. Normally if we used this manure as fertilizer it tends to just burn the grass, but it seemed to be just as deadly to the poison oak.

Has anyone else heard of horse manure killing poison oak like this before?


Hi Alyssa,
Thanks for the good information. This post, on killing poison oak/ivy, is one of the most popular here on greensideupblog so the more information that gets passed around from people like you the better.
As for your story I have a couple of thought. 1) Raw, uncomposted manuer is very high in salt and enough salt will kill nearly any plant. 2) If any plant is covered with enough material to block out all sunlight for an extended period it will die. It sounds like you did both.:)
Either one of these will result in dead plants.
I know of one guy who covered his poison ivy with a two foot deep layer of mulch and was successful in eradicating it from the area.
I really like his mulch and your manuer method because neither involved bad chemical and the less of those used the better.
Thanks for dropping by.


Will gas kill poison Ivey or Oak plants? There is one or the other growing up my tree and my daughter keeps breaking out just being around the tree. If anyone could help me that would be wonderful!

Daniel Lee Snyder

use used antifrese , kills in 3 days will also kill dogs & cats keep away


Please don’t suggest using anti-freeze. It’s quite toxic to ALL living things. There are better solutions.


Hello Caroline,
That sounds like it could work and I like the idea of a very focused application of chemicals rather than a wide spray application. It would probably be the most effective in the late summer or fall while the plant is storing up food in it’s roots……
Let me know how it works out.

Carolyn Merrill

I have this idea (have done this for worms in wood furniture while living in Chile) of cutting back all the way to the root ball and then using a syringe to inject round up into the root. Does this sound plausable? (I too NEVER use chemicals but my husbandis highly allergic).


How about acetic acid. I’ve been reading about vinegar, orange oil and soap solutions Killing weeds. Will it work on poison oak too?


It’s late 06. in Northern California. ..wondering if this the best time to be hacking away the poison oak plaguing my backyard. I just discovered your blog. Very informative. Although I have never had a reaction to it (poison oak, not your blog ) I do know that anyone can get it. It can build up in your system until one day …bummer. And VINEGAR does NOT work. I’ve emptied more vinegar and pickle jars than one could imagine to no avail. ..just a stinky backyard. So I suppose it’s time for some roundup. Is this going to work now that I’ve already chopped it down to a few inches ??

Laurie Bergene

I own a very large back yard full of beautiful oak trees and a large jungle of poison ivy and poison oak. My front is decent with a mowed lawn. Again my back yard is huge!!! A friend is nice to mow the front but i can’t get anyone to do the back. Actually I like the “jungle look” but I doubt my neighbors do. Fear of snakes and all. It needs to go.
I:00disabled and unable to be able to afford taking care of it. Plus I have 6 feral cats that I trapped, fixed and taking care of them. I’m from the California desert and haven’t been here long. It’s all new to me. Any help out there?

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