Host an Event Volunteer Join Tickets

Support the plant database you love!

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?

Share

Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
See a list of all Smarty Plants questions

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

Need help with plant identification, visit the plant identification page.

 
rate this answer
Not Yet Rated

Tuesday - April 19, 2005

From: Blanco, TX
Region: Southwest
Topic: Invasive Plants, Problem Plants
Title: Methods of controlling poison ivy
Answered by: Nan Hampton

QUESTION:

What do you suggest for controlling poison oak (ivy)?

ANSWER:

Since many people are sensitive, some severely, to poison ivy (Toxicodendron spp.), it is not an easy plant to control. If you have a small amount of poison ivy, the sooner you start the easier it will be to control it. The method you use to control it will depend on your sensitivity to the urushiol oil from the plant that causes the itching. If you know that you are sensitive to the urushiol, you might be wise to hire someone who is not sensitive to remove the plants since the most ecologically friendly method for eliminating them is to pull them out of the ground. Pulling them up should include getting as much of the root system out of the ground as possible. The plants will come out of the ground easier if the ground is wet. You (or the person who is removing the plants), even if you believe you are not sensitive to urushiol oil, should protect yourself well while doing this. You should wear gloves, long sleeves, long pants, and boots or shoes with socks. To protect yourself even more you can put your gloved hand in a plastic bag before you grasp the plant to pull it out of the ground. As the plant is pulled out of the ground, the plastic bag can be pulled over the plant to cover it. After you have disposed of the secured plastic bags of plants in the trash, you should thoroughly wash all clothing and yourself. If the plants resprout from any roots that were not removed, you will need to repeat the procedure and try to dig the roots out of the ground. If you are dealing with a large amount of poison ivy to remove, pulling it up may not be practical. In such a case, cutting it near to the ground with long-handled clippers or equivalent device would be better. Shoots will still sprout from the roots, but continued cutting of the shoots should result in starving and killing the roots. It is not recommended to mow the plants since this would shred the plant releasing more of the oil and spreading it everywhere a cut piece is deposited. Burning is also not recommended since the windborn ash from the burning will contain the oil. Tilling the plants under will get rid of the immediate problem but unless the roots are removed, the plants will resprout. Incidentally, if your poison ivy is a vine that has made its way up into a tree, you would be better off severing the vine from the roots in the wintertime when the plant is dormant and the leaves have fallen. Otherwise, you are going to have a tree full of rather unsightly dead poison ivy leaves.

Although we do not generally recommend using herbicides, in the case of a plant that causes severe physical distress like poison ivy, there are herbicides that can be applied if done in a judicious manner. After removing the plants and as much of the roots as possible, you could treat regrowth by painting small amounts of herbicide on sprouting leaves. Painting restricts the herbicide to the plants you want to kill and not to nearby desirable plants. It also eliminates the amount of herbicide you are releasing into the environment. You can read about appropriate herbicides and other methods of control of poison ivy in articles prepared by the Ohio State University Extension Service.

If you have bare skin that has been exposed directly to poison ivy plants, washing with soap and cool water should remove most of the urushiol. Avoid warm water since it may help the oil penetrate the skin. There are products that reportedly remove the urushiol oil from the skin after exposure that you can find by googling "removing urushiol oil".

 

More Problem Plants Questions

Smoking mint instead of tobacco from Fairfield CA
March 23, 2013 - I realize this is a stupid question, but i am a little curious about this. Anyway I heard more people are smoking mint leaves to help cure their addiction to tobacco and i was wondering if it is s...
view the full question and answer

Identification of potentially toxic weed in California
May 08, 2015 - Hi! Sorry about the error, I'm not very computer savvy! I have a weed that grows on my land; about 1 foot tall its flower looks like a Q-tip. My neighbor says it killed her horse! I can't find i...
view the full question and answer

Should Mexican milkweed (Asclepias curassavica) not be used to attract Monarch butterflies?
November 20, 2015 - Should I remove Asclepias curassavica (Mexican milkweed) in my garden for threat of OE parasitic protozoan threat to Monarch butterflies? Is this threat as widespread as Chronicle implies? I had great...
view the full question and answer

How to Control Poison Ivy
February 22, 2016 - We have lots of Poison Ivy on a site we are clearing it is adjacent to a pond and children are around this area all the time. We are creating hiking paths. I have a lot of experience but I do not wan...
view the full question and answer

Black Walnut tree in LA
March 12, 2012 - I was just given a black walnut tree and am trying to determine where to place it. I’ve read on your site that “Certain plants will not grow under Black Walnut trees because of the juglones that the ...
view the full question and answer

Support the Wildflower Center by Donating Online or Becoming a Member today.