# Best way to kill a plant/tree **URL:** \ **Category:** Factual Questions\ **Created:** [May 12, 2003, 12:25pm UTC](https://boards.straightdope.com/t/best-way-to-kill-a-plant-tree/174674 "2003-05-12T12:25:51Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Jdeforrest](https://avatars.discourse-cdn.com/v4/letter/j/49beb7/32.png) [@Jdeforrest](https://boards.straightdope.com/u/Jdeforrest)\ **Post date:** [May 12, 2003, 3:07pm UTC](https://boards.straightdope.com/t/best-way-to-kill-a-plant-tree/174674/21 "2003-05-12T15:07:04Z")
Oops, sorry about the double post. My username? First letter first name and last name. I find it easier than using several usernames across the internet. You know how it is, 1 username will work here, but in another place it’s take, bah, too much work remembering them all. ---
**Author:** ![lieu](https://avatars.discourse-cdn.com/v4/letter/l/c2a13f/32.png) [@lieu](https://boards.straightdope.com/u/lieu)\ **Post date:** [May 12, 2003, 3:16pm UTC](https://boards.straightdope.com/t/best-way-to-kill-a-plant-tree/174674/22 "2003-05-12T15:16:55Z")
The reason I ask… deforrest: How do you kill a tree? ---
**Author:** ![Jdeforrest](https://avatars.discourse-cdn.com/v4/letter/j/49beb7/32.png) [@Jdeforrest](https://boards.straightdope.com/u/Jdeforrest)\ **Post date:** [May 12, 2003, 3:19pm UTC](https://boards.straightdope.com/t/best-way-to-kill-a-plant-tree/174674/23 "2003-05-12T15:19:53Z")
Thought that might be what you were getting at 🙂 I should have been a logger 😉 ---
**Author:** ![twickster](https://avatars.discourse-cdn.com/v4/letter/t/ec9cab/32.png) [@twickster](https://boards.straightdope.com/u/twickster)\ **Post date:** [May 12, 2003, 3:21pm UTC](https://boards.straightdope.com/t/best-way-to-kill-a-plant-tree/174674/24 "2003-05-12T15:21:13Z")
Keep in mind that these plants are very, very poisonous in all their parts – including smoke from burning them. You may want to consider bringing in a pro, seriously. ---
**Author:** ![Jdeforrest](https://avatars.discourse-cdn.com/v4/letter/j/49beb7/32.png) [@Jdeforrest](https://boards.straightdope.com/u/Jdeforrest)\ **Post date:** [May 12, 2003, 3:44pm UTC](https://boards.straightdope.com/t/best-way-to-kill-a-plant-tree/174674/25 "2003-05-12T15:44:42Z")
Okay, time to let out a part of the story that I didn’t want to mention. The plants and tree are actually in a ajoining yard. There’s more to the story, but I’m going to simplify things and say that the neighbor is family and we are unable to get local authorities to MAKE her cut it down and she won’t let us bring in a professional. So it’s kind of a covert operation. Not that we don’t have a good relationship with her, she just refused to have anything done about the health hazard that’s in a part of her backyard that she doesn’t have to go into and is right next to the adjoining fence. Anyway, seeing how this activity is probably illegal. I’m expecting the threat to end shortly. That’s why I was looking for some type of caustic substance or something to take care of the roots permanently and completely. ---
**Author:** ![ratatoskK](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ratatoskk/32/2987_2.png) [@ratatoskK](https://boards.straightdope.com/u/ratatoskK)\ **Post date:** [May 12, 2003, 3:47pm UTC](https://boards.straightdope.com/t/best-way-to-kill-a-plant-tree/174674/26 "2003-05-12T15:47:54Z")
If it’s a woody plant like poison ivy, I have found that Brush-B-Gone, which is specifically designed for woody plants, works better than roundup. Make it triple strength, apply on a sunny, calm day, and re-apply a few hours later. ---
**Author:** ![MaryEFoo](https://avatars.discourse-cdn.com/v4/letter/m/ba8739/32.png) [@MaryEFoo](https://boards.straightdope.com/u/MaryEFoo)\ **Post date:** [May 12, 2003, 5:24pm UTC](https://boards.straightdope.com/t/best-way-to-kill-a-plant-tree/174674/27 "2003-05-12T17:24:06Z")
Yes, use something designed for the purpose: Round-Up, Brush-Be-Gone, Finale. Good reasons: A) they are metabolized and stop being poisonous in less than 24 hours; B) they don’t kill animals etc; and C) they work. It’s legitimate in my area to spray or prune any part of the plant reaching over the line into your property. Waiting till the wind is blowing gently from you toward them, and making sure a lot of spray gets onto a lot of the plant’s leaves and stems, well that’s up to your ethics. In any case, pls consider the negative results if the spray wipes out half the rest of their backyard plants. A more minimalist method would just to keep spraying all the sprouts upcoming, and any branch coming over the fence. Once the sprouts stop coming, put a barrier in the soil so the roots don’t keep growing under the fence. The barrier can be plastic, say 8" deep, and slanted a little so an exploring root comes **up** into visibility where you can whack it. Cutting anything related to poison ivy is going to get the sap (urushiol) onto the person cutting. Some people are immune; they know who they are. Or you could take precautions. How did it hospitalize people? Some people are very sensitive to touching urushiol, and it can \*\*really be a problem if someone breathes smoke from burning the stuff, or eats a leaf. ---
**Author:** ![Jdeforrest](https://avatars.discourse-cdn.com/v4/letter/j/49beb7/32.png) [@Jdeforrest](https://boards.straightdope.com/u/Jdeforrest)\ **Post date:** [May 12, 2003, 5:41pm UTC](https://boards.straightdope.com/t/best-way-to-kill-a-plant-tree/174674/28 "2003-05-12T17:41:34Z")
Apparently it’s of an unusually strong strain or something and anyone who winds up touching it has to get steroid shots to rid themselves of it. It just won’t clear up using ordinary means. After reading all of these responses and from what I know of the situation, it doesn’t seem likely that they will be able to kill the tree without professional help. I bet that I could probably dump several bottles of a herbacide on it and it would be back again another year because who is going to go out and start digging up roots once it appears dead? I myself don’t like hospitals 😉 Putting a barrier underground is a good suggestion. I’m going to have to mention that to them. ---
**Author:** ![DeVena](https://avatars.discourse-cdn.com/v4/letter/d/dec6dc/32.png) [@DeVena](https://boards.straightdope.com/u/DeVena)\ **Post date:** [May 12, 2003, 5:44pm UTC](https://boards.straightdope.com/t/best-way-to-kill-a-plant-tree/174674/29 "2003-05-12T17:44:04Z")
> [@](#): > > \*Originally posted by Jdeforrest \* > \*\*WELL, mister condescending, according to my state regulations [http://www.pacode.com/secure/data/025/chapter291/chap291toc.html](http://www.pacode.com/secure/data/025/chapter291/chap291toc.html) (please reference article 291.203) it doesn’t seem like the activity was illegal and I therefore ask you to cite the law or regulation that makes such an activity illegal. And I’d also ask to explain why it was stupid since it doesn’t seem to present any risk to the surrounding environment or anyones health. \*\* UMMMmmm, Maybe you need to check your facts. Used Oil is managed under Code 298 in Pennsylvania. [And this page should help you understand the regulations.](http://www.dep.state.pa.us/dep/deputate/airwaste/wm/Oil/Facts/Used_Oil.htm) Specifically the Disposal section. Used Oil is managed on a Federal level under 40 CFR 279. Dumping used oil is not good and most states prohibit it’s use as a dust suppressant. Sorry for the hijack… Carry on. ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [May 12, 2003, 5:47pm UTC](https://boards.straightdope.com/t/best-way-to-kill-a-plant-tree/174674/30 "2003-05-12T17:47:13Z")
> [@](#): > > \*Originally posted by Jdeforrest \* > WELL, mister condescending, according to my state regulations [http://www.pacode.com/secure/data/025/chapter291/chap291toc.html](http://www.pacode.com/secure/data/025/chapter291/chap291toc.html) (please reference article 291.203) it doesn’t seem like the activity was illegal and I therefore ask you to cite the law or regulation that makes such an activity illegal. And I’d also ask to explain why it was stupid since it doesn’t seem to present any risk to the surrounding environment or anyones health. Motor oil is extremely contaminating and hazardous and anyone who is not very ignorant should know this. A [google search yields thousands of pages](http://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=environment+illegal+dump+motor+oil) saying it is illegal to dump motor oil. Here’s just one: > [@](#): > > [http://www.castrolusa.com/expert/ae\_article.asp?article\_id=17§ion\_id=3](http://www.castrolusa.com/expert/ae_article.asp?article_id=17§ion_id=3) > > Motor Oil and the Environment > > If you’ve chosen to replace the oil in your vehicle yourself, you’ve also accepted the responsibility to properly dispose of the resulting waste. Exposure to used motor oil not only poses a danger to your health, but it’s also a hazard to the environment. It is illegal to dump used motor oil into garbage bins, down kitchen sinks and storm drains, and into sewers and rivers. Pouring it on the ground is not only illegal - it’s probably the worst thing you can do! > > The used oil from a single oil change may look as harmless as dirty dishwater, but nothing could be further from the truth. A single gallon of used oil can contaminate a million gallons of fresh water, an amount equal to a year’s supply of drinking water for 50 people. Even as little as a single pint of oil can create an oil slick the size of a football field! Once you realize how little it takes to cause widespread contamination, it’s easy to see that you must properly dispose of this extremely hazardous and highly common waste. Dumping oil in sewers is NOT an option; sewers lead to waste treatment plants, which will have a difficult - not to mention expensive - time removing the oil from water intended for humans. Dump the oil on the ground and eventually it will find it’s way to sewer grates, and from there to the waste treatment plant. Storm drains lead to streams, rivers and lakes in our communities, potentially poisoning these waters for fish and other wildlife - not to mention pets and the occasional human bather. And yet, each year in the U.S. alone, we throw out more than 20 times as much oil as was spilled by the infamous Exxon Valdez. Furthermore, either you are authorised to do this or you aren’t. If what you are doing is legal, then do it right and do it legally. If you are not authorised to do what you are doing, trying to do it with motor oil only adds another illegal act to the one you are already doing. You seem to be doing two illegal things at once and something very stupid because you are doing something illegal which does not even work for what you want. We have laws for a reason. Why don’t you just respect them? ---
**Author:** ![Brave\_Sir\_Robin](https://avatars.discourse-cdn.com/v4/letter/b/a183cd/32.png) [@Brave\_Sir\_Robin](https://boards.straightdope.com/u/Brave_Sir_Robin)\ **Post date:** [May 12, 2003, 6:06pm UTC](https://boards.straightdope.com/t/best-way-to-kill-a-plant-tree/174674/31 "2003-05-12T18:06:02Z")
Check your local agricultural products store. They’ll have stuff that will kill almost anything. I know that my parents used to use Princep to very effectively eliminate weeds. It is probably more rigorously controlled now, though. ---
**Author:** ![netscape\_6](https://avatars.discourse-cdn.com/v4/letter/n/8c91f0/32.png) [@netscape\_6](https://boards.straightdope.com/u/netscape_6)\ **Post date:** [May 12, 2003, 6:15pm UTC](https://boards.straightdope.com/t/best-way-to-kill-a-plant-tree/174674/32 "2003-05-12T18:15:16Z")
> [@](#): > > \*Originally posted by sailor \* > \*\* We have laws for a reason. Why don’t you just respect them? \*\* \ i am very pro-enviroment. i agree pouring oil on the ground was a bad thing to do. however this plant has hospitialized his family members on 2 occuasions. the moter oil was wrong, however given the danger this plant posse to his(maybe her) family i think endevering to kill that plant is morally correct. i might be going to court becouse a wind turbine i am planning to put up violates a town zoning oridenance. should continue to hurt mother by burning fossil fuels for electricity just to follow some dumb law? \ as for the OP, have you considered kudzu? it should joke the rival plant out and die this winter. ---
**Author:** ![DeVena](https://avatars.discourse-cdn.com/v4/letter/d/dec6dc/32.png) [@DeVena](https://boards.straightdope.com/u/DeVena)\ **Post date:** [May 12, 2003, 6:25pm UTC](https://boards.straightdope.com/t/best-way-to-kill-a-plant-tree/174674/33 "2003-05-12T18:25:29Z")
**netscape 6** , I’m having trouble understanding your post. But I believe **sailor** was not commenting on the OP. He was in reference to the “mister condescending” post of **Jdeforrest**. I think we all understand that the OP’s family is trying to do all they can to kill this noxious plant. But used oil will not work nearly as fast as Round-up. And after the plant dies, the family will still need to contract with an outside party to remove the tree. It will still affect them, even if the tree is dead. ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [May 12, 2003, 6:32pm UTC](https://boards.straightdope.com/t/best-way-to-kill-a-plant-tree/174674/34 "2003-05-12T18:32:59Z")
Motor oil is not effective for killing plants Motor oil is very contaminating It is illegal to dump motor oil There are commercial products designed for this specific purpose. netscape 6, I am sorry but I have NO sympathy for those who break the law for no reason. This is plain stupid. Where did he get the idea that motor oil is the best way to kill a plant? Couldn’t he ask _before_ doing anything? Let us assume the neighbor is creating a nuisance. That is why we have courts. And, in any case, he is free to trim and cut and clear all the part of the plant which is on his property. And I can’t see why they need to go up to the part of the fence where the plant is. Or is it that the yard is 3 feet wide? There is just _no_ excuse for pouring motor oil. As I said, killing a virgin is about as effective. ---
**Author:** ![netscape\_6](https://avatars.discourse-cdn.com/v4/letter/n/8c91f0/32.png) [@netscape\_6](https://boards.straightdope.com/u/netscape_6)\ **Post date:** [May 12, 2003, 7:00pm UTC](https://boards.straightdope.com/t/best-way-to-kill-a-plant-tree/174674/35 "2003-05-12T19:00:19Z")
i’m sorry i just noticed my typo. joke should be choke (how did i make that typo?😕 ) anyway the idea is kudzu will grow like it does in the south this summer and choke out the offending plant. what plant can compete with kudzu? anyway the Pennsylvania winter should kill the kudzu. **sailor** : if you were just chewing him out for the motor oil alone i support that. it’s just there is alot of dumb laws and saying we should follow all them (as i took that last part to mean) is not rational. that said dumping the motor oil was incredbly stupid and agree with that. they should throw the book at oil dumpers. ---
**Author:** ![MaryEFoo](https://avatars.discourse-cdn.com/v4/letter/m/ba8739/32.png) [@MaryEFoo](https://boards.straightdope.com/u/MaryEFoo)\ **Post date:** [May 12, 2003, 7:09pm UTC](https://boards.straightdope.com/t/best-way-to-kill-a-plant-tree/174674/36 "2003-05-12T19:09:03Z")
Finale, Round-Up, etc, kill the whole plant, **starting** with the roots. But if you can only spray 5% of the plant, it will probably survive. You won’t see it beginning to wilt for probably two weeks. The sooner it’s sprayed, the sooner the two weeks will begin. I’m glad you will mention the root barrier to them, it really does work, if they don’t want to spray it. See specs above for depth and tilt. The person digging the slot for the barrier needs to wear gloves, and wash tools, self, and laundry immediately after. Wash your skin within 15 minutes with rubbing alcohol (or even beer). Don’t **scour** your skin when washing. Send the rinsings right down the drain. ---
**Author:** ![Happy\_Fun\_Ball](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/happy_fun_ball/32/17664_2.png) [@Happy\_Fun\_Ball](https://boards.straightdope.com/u/Happy_Fun_Ball)\ **Post date:** [May 12, 2003, 7:13pm UTC](https://boards.straightdope.com/t/best-way-to-kill-a-plant-tree/174674/37 "2003-05-12T19:13:29Z")
Last year the missus and I had some trees removed from our property. When the tree people were here I asked them the best way to kill a few stumps that were continuing to sprout even though the trees had been gone for years. I was told that a cheap and very effective way to kill a tree is to drill a few holes in it with a 3/4" - 1" drill bit and fill the holes with salt. I was told that this would kill off the whole tree, even the little trees that sprout from the roots twenty feet away from the main trunk. [mini-rant commence] &%\*#&^% what are those stupid little offshoot trees called? suckers, no, feeders, no, damn my memory! I hate getting old! [end mini-rant] I don’t think this would be too environmentally dangerous, though I suppose you might get a few deer licking the tree for a while. BTW, I never did try this so YMMV. I finally just pulled the stumps up with a truck and a hoist. ---
**Author:** ![Jdeforrest](https://avatars.discourse-cdn.com/v4/letter/j/49beb7/32.png) [@Jdeforrest](https://boards.straightdope.com/u/Jdeforrest)\ **Post date:** [May 12, 2003, 7:17pm UTC](https://boards.straightdope.com/t/best-way-to-kill-a-plant-tree/174674/38 "2003-05-12T19:17:03Z")
Okay. I can’t look through laws anymore. My head is starting to go numb. The cite I quoted was for residual waste. Though I couldn’t find anything specific to oil in the federal code that Devena posted, it does list it as a hazardous material so I’m sure a whole new set of guidelines exist. Sailor, I didn’t dump the oil nor anything else, so all I could be guilty of is conspiracy. And though I didn’t do anything wrong, if I were in their position, I would dump anything I had to onto that plant to kill it. The law isn’t protecting their family from getting sick, which IMO trumps the minimal environmental affect it would have. For further information, the water table is several feet down and there are no ground wells or nearby bodies of water, so contamination risk should be very, very, very low. But anyway, this is a GQ question and we’ve went through a major hijack. Neither my opinion on the laws or whether in fact you are allowed to dump oil applies since that wasn’t even suggested. ---
**Author:** ![Happy\_Fun\_Ball](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/happy_fun_ball/32/17664_2.png) [@Happy\_Fun\_Ball](https://boards.straightdope.com/u/Happy_Fun_Ball)\ **Post date:** [May 12, 2003, 7:19pm UTC](https://boards.straightdope.com/t/best-way-to-kill-a-plant-tree/174674/39 "2003-05-12T19:19:26Z")
> [@](#): > > _Originally posted by me \* > \*\*[mini-rant commence] &%_#&^% what are those stupid little offshoot trees called? suckers, no, feeders, no, damn my memory! I hate getting old! > [end mini-rant] > \*\* This was bothering me so much I actually had to get down the dictionary. They are called suckers. I don’t know which is worse, not being able to remember a term or not knowing if the term you remembered is correct or not! Damn Brain. ---
**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\ **Post date:** [May 12, 2003, 8:22pm UTC](https://boards.straightdope.com/t/best-way-to-kill-a-plant-tree/174674/40 "2003-05-12T20:22:10Z")
> [@](#): > > \*Originally posted by Jdeforrest \* > Sailor, I didn’t dump the oil nor anything else, so all I could be guilty of is conspiracy. And though I didn’t do anything wrong, if I were in their position, I would dump anything I had to onto that plant to kill it. The law isn’t protecting their family from getting sick, which IMO trumps the minimal environmental affect it would have. For further information, the water table is several feet down and there are no ground wells or nearby bodies of water, so contamination risk should be very, very, very low. Trying to defend the position “The problem is so serious I will resort to illegal means which do not work rather than legal means which do work” is kind of pretty stupid if you ask me. The reasoning that “I would dump anything I had to onto that plant to kill it.” is just plain stupid and you keep insisting on it. Follow me: (a) Dumping oil will not work and therefore it is stupid whether it is legal or illegal. Furthermore (b) dumping oil is illegal and contaminating. There are perfectly effective and legal means of dealing with the problem so resorting to illegal means is plain antisocial. But if those means do not work they are stupid as well. There is simply NO justification for dumping oil in the ground. You are trying to defend something which is illegal _plus_ stupid. Both things are frowned upon on this board. Just so you know: When I am refueling my boat, if I spill the least amount, if it makes a sheen on the water, I get a ticket. Just a few drops will do it. The stuff is hazardous. Put that in your head. Hazardous. [Previous page](https://boards.straightdope.com/t/best-way-to-kill-a-plant-tree/174674.md?page=1) [Next page](https://boards.straightdope.com/t/best-way-to-kill-a-plant-tree/174674.md?page=3)