# Nicotine and plants **URL:** \ **Category:** Cecil's Columns/Staff Reports\ **Created:** [December 16, 2008, 4:07pm UTC](https://boards.straightdope.com/t/nicotine-and-plants/477409 "2008-12-16T16:07:56Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![guizot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/guizot/32/3636_2.png) [@guizot](https://boards.straightdope.com/u/guizot)\ **Post date:** [December 16, 2008, 4:07pm UTC](https://boards.straightdope.com/t/nicotine-and-plants/477409/1 "2008-12-16T16:07:56Z")
I read an Agatha Cristie book where the victim was killed with nicotine. I couldn’t figure out why someone would have a box of nicotine around the house until finally in the book it was mentioned that the gardener used it on plants as an insecticide. So Cecil’s suggestion of the cigarette butts just might work on the guy’s pot plants. ---
**Author:** ![John\_W.Kennedy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_w.kennedy/32/1031_2.png) [@John\_W.Kennedy](https://boards.straightdope.com/u/John_W.Kennedy)\ **Post date:** [December 16, 2008, 4:51pm UTC](https://boards.straightdope.com/t/nicotine-and-plants/477409/2 "2008-12-16T16:51:24Z")
Tobacco plants evolved nicotine as an insecticide. That humans get an addictive kick out of very, very small amounts is an accident. ---
**Author:** ![bibliophage](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bibliophage/32/7615_2.png) [@bibliophage](https://boards.straightdope.com/u/bibliophage)\ **Post date:** [December 16, 2008, 5:22pm UTC](https://boards.straightdope.com/t/nicotine-and-plants/477409/3 "2008-12-16T17:22:46Z")
A link to the column is appreciated. [My marijuana plants have bugs! What do I do? - The Straight Dope](http://www.straightdope.com/columns/read/22/my-marijuana-plants-have-bugs-what-do-i-do) ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [December 16, 2008, 5:32pm UTC](https://boards.straightdope.com/t/nicotine-and-plants/477409/4 "2008-12-16T17:32:40Z")
> [@](#): > > Tobacco plants evolved nicotine as an insecticide. That humans get an addictive kick out of very, very small amounts is an accident. The same is true of caffeine, and probably most other plant-derived drugs. ---
**Author:** ![Great\_Dave](https://avatars.discourse-cdn.com/v4/letter/g/46a35a/32.png) [@Great\_Dave](https://boards.straightdope.com/u/Great_Dave)\ **Post date:** [December 16, 2008, 7:25pm UTC](https://boards.straightdope.com/t/nicotine-and-plants/477409/5 "2008-12-16T19:25:47Z")
> [@Chronos](#): > > The same is true of caffeine, and probably most other plant-derived drugs. I’d say that all chemicals in plants that are not involved in metabolism are for some sort of defense. It’s the only way plants can defend themselves. ---
**Author:** ![Great\_Dave](https://avatars.discourse-cdn.com/v4/letter/g/46a35a/32.png) [@Great\_Dave](https://boards.straightdope.com/u/Great_Dave)\ **Post date:** [December 28, 2008, 2:22am UTC](https://boards.straightdope.com/t/nicotine-and-plants/477409/6 "2008-12-28T02:22:37Z")
When I was in Investigations in Plant Ecology, my experiment involved spraying rapeseed plants with various concentrations of nitric or sulfuric acid. I used nicotine to kill mites. One can put a butt in to a spray bottle, or put the whole plant in a large can, put a lit cigarette, and cover. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [December 28, 2008, 3:28am UTC](https://boards.straightdope.com/t/nicotine-and-plants/477409/7 "2008-12-28T03:28:16Z")
> [@Great\_Dave](#): > > It’s the only way plants can defend themselves. I don’t think that’s really true. It’s _a_ way plants defend themselves, but certainly not the _only_ way. Take certain species of the [acacia](http://en.wikipedia.org/wiki/Acacia#Symbiosis), for instance: > [@](#): > > In the Central American Acacia sphaerocephala, Acacia cornigera, and Acacia collinsii (collectively known as the bullthorn acacias), the large thorn-like stipules are hollow and afford shelter for ants, which feed on a secretion of sap on the leaf-stalk and small, lipid-rich food-bodies at the tips of the leaflets called Beltian bodies; in return they add protection to the plant against herbivores.[2] Some species of ants will also fight off competing plants around the acacia, cutting off the offending plant’s leaves with their jaws and ultimately killing it, while other ant species will do nothing to benefit their host. ---
**Author:** ![levdrakon](https://avatars.discourse-cdn.com/v4/letter/l/49beb7/32.png) [@levdrakon](https://boards.straightdope.com/u/levdrakon)\ **Post date:** [December 28, 2008, 3:39am UTC](https://boards.straightdope.com/t/nicotine-and-plants/477409/8 "2008-12-28T03:39:14Z")
YMMV I guess. I’ve used the cigarette butts in water technique to kill aphids and scale and it didn’t work. I used a couple ashtrays full of butts too, 'cause I really wanted those bugs dead. ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [December 28, 2008, 5:38am UTC](https://boards.straightdope.com/t/nicotine-and-plants/477409/9 "2008-12-28T05:38:32Z")
I haven’t seen nicotine sold as an insecticide commercially for years (it used to be marketed under names like Black Leaf 40), and for good reason - it was effective and environmentally relatively safe (it broke down quickly), but also very toxic to humans if used without adquate protection (I never felt good about using products whose warnings included words like FATAL). Using home concoctions derived from cigarette butts carries some risk as well, though these preparations are typically going to be a lot weaker. Cecil’s column from 1975 looks amazingly anachronistic from a gardener’s perspective, except for the advice on using pyrethrum (still a pretty good choice). Insecticidal soaps and Neem are near the top of the list today for killing off aphids in an environmentally responsible way, though simply washing aphids off leaves with a spray of water (if you keep at it) works nicely too. By the way, Cecil’s diagnosis of the problem is probably wrong - what the letter writer describes sounds more like spider mites than aphids (aphids are usually pale yellow and green, and don’t typically cause the leaf speckling that’s described). Mites are a nastier problem to deal with, though soaps and Neem have some usefulness in controlling them. ---
**Author:** ![SeanArenas](https://avatars.discourse-cdn.com/v4/letter/s/df705f/32.png) [@SeanArenas](https://boards.straightdope.com/u/SeanArenas)\ **Post date:** [December 28, 2008, 5:24pm UTC](https://boards.straightdope.com/t/nicotine-and-plants/477409/10 "2008-12-28T17:24:30Z")
Is it considered environmentally healthy to use a predator insect to eat the aphids and mites? I think that ladybugs and lacewing flies (for example) have no (as far as I know) detrimental effects to the plants, and yet eat aphids or mites, right? I know gardening supply stores sell boxes of ladybugs, and I’ve seen lacewing flies about 6 months out of a year around my apartment. ---
**Author:** ![Toaster](https://avatars.discourse-cdn.com/v4/letter/t/7bcc69/32.png) [@Toaster](https://boards.straightdope.com/u/Toaster)\ **Post date:** [December 28, 2008, 7:57pm UTC](https://boards.straightdope.com/t/nicotine-and-plants/477409/11 "2008-12-28T19:57:43Z")
Some of these predators can be pests, and can threaten or overpower normal wildlife if introduced to an area in which they are not native. For example, one species of ladybug has been imported to North America and become a pest themselves. ( [Coccinellidae - Wikipedia](http://en.wikipedia.org/wiki/Coccinellidae#Coccinellids_as_household_pests) ) It is best to only use predators which are native to the area in which you will use them. They may significantly harm native wildlife, or become pests in other ways.