# Does weed-killer go bad? **URL:** \ **Category:** In My Humble Opinion\ **Created:** [April 19, 2005, 3:39pm UTC](https://boards.straightdope.com/t/does-weed-killer-go-bad/300064 "2005-04-19T15:39:44Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![I\_can\_t\_believe\_that\_s\_butter](https://avatars.discourse-cdn.com/v4/letter/i/8edcca/32.png) [@I\_can\_t\_believe\_that\_s\_butter](https://boards.straightdope.com/u/I_can_t_believe_that_s_butter)\ **Post date:** [April 19, 2005, 3:39pm UTC](https://boards.straightdope.com/t/does-weed-killer-go-bad/300064/1 "2005-04-19T15:39:44Z")
Our lawn is in appalling need of a weed-killing, and I found a half-bottle of some “kills everything but bermuda and bent grass” stuff—Weed-Be-Gone, I want to say? However, I think the bottle is about ten years old. Would it still be okay to use? ---
**Author:** ![Jophiel](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jophiel/32/66_2.png) [@Jophiel](https://boards.straightdope.com/u/Jophiel)\ **Post date:** [April 19, 2005, 3:56pm UTC](https://boards.straightdope.com/t/does-weed-killer-go-bad/300064/2 "2005-04-19T15:56:44Z")
It won’t _hurt_ anything to try it but the active chemicals have probably broken down and become inert by now and you’ll be spraying worthless chemicals on the lawn. I’d just pick up a new bottle at the local nursery or hardware store given the relatively low cost of herbicides. ---
**Author:** ![Adking](https://avatars.discourse-cdn.com/v4/letter/a/7993a0/32.png) [@Adking](https://boards.straightdope.com/u/Adking)\ **Post date:** [April 19, 2005, 4:45pm UTC](https://boards.straightdope.com/t/does-weed-killer-go-bad/300064/3 "2005-04-19T16:45:15Z")
I read this as, “Does killer weed go bad?” 😃 ---
**Author:** ![Kent\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kent_clark/32/105_2.png) [@Kent\_Clark](https://boards.straightdope.com/u/Kent_Clark)\ **Post date:** [April 19, 2005, 4:49pm UTC](https://boards.straightdope.com/t/does-weed-killer-go-bad/300064/4 "2005-04-19T16:49:42Z")
> [@Jophiel](#): > > It won’t _hurt_ anything to try it but the active chemicals have probably broken down and become inert by now and you’ll be spraying worthless chemicals on the lawn. I’d just pick up a new bottle at the local nursery or hardware store given the relatively low cost of herbicides. But you might want to call your local Dept. of Health or Waste Management or Environmental Protection and ask the best way to safely dispose of old chemicals. ---
**Author:** ![Metacom](https://avatars.discourse-cdn.com/v4/letter/m/ecae2f/32.png) [@Metacom](https://boards.straightdope.com/u/Metacom)\ **Post date:** [April 19, 2005, 4:52pm UTC](https://boards.straightdope.com/t/does-weed-killer-go-bad/300064/5 "2005-04-19T16:52:25Z")
What are the active ingredients? Should be clearly listed on the bottle… And not all herbicides are cheap, especially if you buy them in concetrates. ---
**Author:** ![I\_can\_t\_believe\_that\_s\_butter](https://avatars.discourse-cdn.com/v4/letter/i/8edcca/32.png) [@I\_can\_t\_believe\_that\_s\_butter](https://boards.straightdope.com/u/I_can_t_believe_that_s_butter)\ **Post date:** [April 19, 2005, 5:07pm UTC](https://boards.straightdope.com/t/does-weed-killer-go-bad/300064/6 "2005-04-19T17:07:36Z")
DMA salt of 2,4-D (2,4-Dichlorophenoxyacetic acid) seems to be the main one. I can’t make out the rest. ---
**Author:** ![Metacom](https://avatars.discourse-cdn.com/v4/letter/m/ecae2f/32.png) [@Metacom](https://boards.straightdope.com/u/Metacom)\ **Post date:** [April 19, 2005, 5:29pm UTC](https://boards.straightdope.com/t/does-weed-killer-go-bad/300064/7 "2005-04-19T17:29:48Z")
2,4-D is a very common broad-leaf herbicide. [Some forms have an indefinite shelf life](http://agebb.missouri.edu/hort/meg/archives/v6n14/meg5.htm)–pick a weed and give it a shot. ---
**Author:** ![Jophiel](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jophiel/32/66_2.png) [@Jophiel](https://boards.straightdope.com/u/Jophiel)\ **Post date:** [April 19, 2005, 5:55pm UTC](https://boards.straightdope.com/t/does-weed-killer-go-bad/300064/8 "2005-04-19T17:55:06Z")
Ortho Weed-B-Gon isn’t one of your more pricey herbicides. I had assumed that it’s not a trigger spray but rather a concentrate for a hose-end sprayer. Seems a waste of time to spend an hour spraying the lawn with impotent chemicals instead of shelling out $15 for a new bottle. If it is a trigger spray, go find a weed and try it. Weed-B-Gon isn’t fast acting though so it’ll take a while to see results even if it is still working. ---
**Author:** ![I\_can\_t\_believe\_that\_s\_butter](https://avatars.discourse-cdn.com/v4/letter/i/8edcca/32.png) [@I\_can\_t\_believe\_that\_s\_butter](https://boards.straightdope.com/u/I_can_t_believe_that_s_butter)\ **Post date:** [April 19, 2005, 6:50pm UTC](https://boards.straightdope.com/t/does-weed-killer-go-bad/300064/9 "2005-04-19T18:50:05Z")
Well, all I really care about is whether the chemicals fermented, and will cause my lawn to rot. 🙂 If they don’t work, there’s hardly any wasted effort other than spraying for a few minutes. So, thank you for the advice, reassurance, etc. I’ll give it a try later. ---
**Author:** ![Toddly](https://avatars.discourse-cdn.com/v4/letter/t/22d042/32.png) [@Toddly](https://boards.straightdope.com/u/Toddly)\ **Post date:** [April 19, 2005, 7:35pm UTC](https://boards.straightdope.com/t/does-weed-killer-go-bad/300064/10 "2005-04-19T19:35:22Z")
Is there any lawn left to save? If so then use a “Weed and Feed” type of lawn application. It will kill broad leaf plants and fertilize the bent grasses. ---
**Author:** ![Lissa](https://avatars.discourse-cdn.com/v4/letter/l/85f322/32.png) [@Lissa](https://boards.straightdope.com/u/Lissa)\ **Post date:** [April 20, 2005, 1:36am UTC](https://boards.straightdope.com/t/does-weed-killer-go-bad/300064/11 "2005-04-20T01:36:32Z")
This thread reminds me of that Far Side cartoon. I keep seeing the weed killer bottle holding the other gardening implements at gunpoint: “_When Weed Killer Goes Bad._”