# Garden work - Weeds in walkway cracks **URL:** \ **Category:** Factual Questions\ **Created:** [June 2, 2009, 10:57pm UTC](https://boards.straightdope.com/t/garden-work-weeds-in-walkway-cracks/498517 "2009-06-02T22:57:30Z")\ **Posts on this page:** 12\ **Page:** 2
**Author:** ![Chief\_Pedant](https://avatars.discourse-cdn.com/v4/letter/c/a6a055/32.png) [@Chief\_Pedant](https://boards.straightdope.com/u/Chief_Pedant)\ **Post date:** [June 3, 2009, 4:40am UTC](https://boards.straightdope.com/t/garden-work-weeds-in-walkway-cracks/498517/21 "2009-06-03T04:40:55Z")
> [@Blake](#): > > All arsenic does is shut an enzyme in the plant that is needed for growth. Do you also consider arsenic not to be a poison? I did not realize arsenic is particularly toxic for plants. Learn something new on this board every day…I did find an article to back up your claim [Taylor & Francis - Fostering human progress through knowledge](http://www.informaworld.com/smpp/content~content=a791938977~db=all~order=page) even though I thought plants just sort of took up As and dealt with it. Under your broader definition of pesticides, would boiling water, vinegar, bleach and so on be also banned if pesticides are banned? They are all chemicals which are apparently biocidal–hot water, anyway… ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [June 3, 2009, 4:50am UTC](https://boards.straightdope.com/t/garden-work-weeds-in-walkway-cracks/498517/22 "2009-06-03T04:50:55Z")
> [@Chief\_Pedant](#): > > I did not realize arsenic is particularly toxic for plants. Hell yeah. Arsenicals were the best selling arboricides in the world for over 100 years. > [@](#): > > I thought plants just sort of took up As and dealt with it. Some plants can accumulate arsenic in a manner that is harmless them, but even they have limits. Most plants are killed of pretty fast by heavy metals, including copper. > [@](#): > > Under your broader definition of pesticides, would boiling water, vinegar, bleach and so on be also banned if pesticides are banned? They are all chemicals which are apparently biocidal–hot water, anyway… That’s a legislative question, and legislation gets to make up its own definitions which have no relationship to the real world.That’s how we get to have an “assault weapons” ban. Normally a pesticide acts through a mechanism that doesn’t cause direct physical harm. So while baseball bats and hot water may kill pests they aren’t normally considered pesticides. ---
**Author:** ![Maastricht](https://avatars.discourse-cdn.com/v4/letter/m/a88e57/32.png) [@Maastricht](https://boards.straightdope.com/u/Maastricht)\ **Post date:** [June 3, 2009, 5:07am UTC](https://boards.straightdope.com/t/garden-work-weeds-in-walkway-cracks/498517/23 "2009-06-03T05:07:51Z")
A more permanent solution, that is also eco-friendly, is this. Get down on your hands and knees one more time, and remove all weeds, preferably with roots and all. Then prepare a mixture of sand and cement. Gentlysprinkle it over your terrace, and sweep it in the cracks. It will fill the cracks and semi-harden there, making it impossible for future weeds to get a foothold there. ---
**Author:** ![GaryM](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/garym/32/241_2.png) [@GaryM](https://boards.straightdope.com/u/GaryM)\ **Post date:** [June 3, 2009, 12:32pm UTC](https://boards.straightdope.com/t/garden-work-weeds-in-walkway-cracks/498517/24 "2009-06-03T12:32:11Z")
> [@Maastricht](#): > > A more permanent solution, that is also eco-friendly, is this. Get down on your hands and knees one more time, and remove all weeds, preferably with roots and all. Then prepare a mixture of sand and cement. Gentlysprinkle it over your terrace, and sweep it in the cracks. It will fill the cracks and semi-harden there, making it impossible for future weeds to get a foothold there. Eco-friendly? Do you know how much fuel it takes to produce Portland Cement? Not to mention the sand! :smack: Just kidding. ---
**Author:** ![twickster](https://avatars.discourse-cdn.com/v4/letter/t/ec9cab/32.png) [@twickster](https://boards.straightdope.com/u/twickster)\ **Post date:** [June 3, 2009, 12:46pm UTC](https://boards.straightdope.com/t/garden-work-weeds-in-walkway-cracks/498517/25 "2009-06-03T12:46:13Z")
> [@chacoguy420](#): > > Gasoline will kill pretty much anything. It’s also pretty toxic and not something you want in the water table. > [@Chief\_Pedant](#): > > Under your broader definition of pesticides, would boiling water, vinegar, bleach and so on be also banned if pesticides are banned? They are all chemicals which are apparently biocidal–hot water, anyway… Leaving aside the “legislators can play any word games they want to” point that **Blake** made, I’m guessing the point of the legislation **Casserole** is attempting to stay within is intended to keep toxins out of the soil/groundwater. Boiling water is definitely not toxic, despite its deleterious effect on plants it’s poured on directly. ---
**Author:** ![AskNott](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asknott/32/5790_2.png) [@AskNott](https://boards.straightdope.com/u/AskNott)\ **Post date:** [June 3, 2009, 4:03pm UTC](https://boards.straightdope.com/t/garden-work-weeds-in-walkway-cracks/498517/26 "2009-06-03T16:03:40Z")
Here’s what Mike McGrath of _You Bet Your Garden_ says about flame weeding: [http://www.gardensalive.com/article.asp?ai=780](http://www.gardensalive.com/article.asp?ai=780) > [@](#): > > Never use vinegar on any kind of paver, brick, flagstone or concrete; it WILL damage the surface. Same for salt. And the oft-recommended ‘boiling water’ will damage your surface. You ever try and carry a big pot of boiling water? It sloshes a little more violently with every step until some goes ever the edge, burns your hand, you drop the pot and scald your legs, feet and tootsies. > > Herbicidal soap sprays are a much more safe and effective walkway weed wanquisher. Similar to insecticidal soaps, they smother their designated pest with a soap-bubble film—and leave your walkway clean and shiny! Soak the weeds well with the soap at the hottest part of the day during a dry spell and they will wither and die. > > And yes, one of my favorite garden tools—the trusty flame weeder—also works very well. I use BernzOmatic’s “Outdoor Torch”; you screw a camp-stove sized propane bottle into one end of the long wand, click the igniter and a cute little flame comes out the other end. Wait for a dry spell, wave the flame over the tops of the weeds, and they will dehydrate and die. Any hardware or home supply store can order one for you, many stores have them in stock this time of year, and you can order directly from BernzOmatic by calling their toll-free #, 1-800-654-9011 (they don’t sell online) ---
**Author:** ![filling\_pages](https://avatars.discourse-cdn.com/v4/letter/f/b9bd4f/32.png) [@filling\_pages](https://boards.straightdope.com/u/filling_pages)\ **Post date:** [June 3, 2009, 4:04pm UTC](https://boards.straightdope.com/t/garden-work-weeds-in-walkway-cracks/498517/27 "2009-06-03T16:04:55Z")
My dad uses the blow torch method. There are several up sides to this, the main one being that _he gets to play with a freakin’ blow torch_! Much more fun than boiling water. Oh, and in reference to the last post: the one dad has doesn’t feature “cute little flames” - when he cranks it up, that baby really roars. It’ll light a bonfire in no time flat, even when it’s been wet out. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [June 3, 2009, 4:23pm UTC](https://boards.straightdope.com/t/garden-work-weeds-in-walkway-cracks/498517/28 "2009-06-03T16:23:07Z")
> [@AskNott](#): > > Here’s what Mike McGrath of _You Bet Your Garden_ says about flame weeding:…“You ever try and carry a big pot of boiling water? It sloshes a little more violently with every step until some goes ever the edge, burns your hand, you drop the pot and scald your legs, feet and tootsies.” There are these things called kettles or teakettles. They have none of those drawbacks, and unilke a flamethrower, you likely already have one. Most surfaces that a little boiling water could damage would also be damaged by a flamethrower. Incidentally, the above quote is why it’s best not to use Quote Blocks to quote non-posters. Just use these little things “”“”. ---
**Author:** ![Voyager](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/voyager/32/133_2.png) [@Voyager](https://boards.straightdope.com/u/Voyager)\ **Post date:** [June 3, 2009, 4:41pm UTC](https://boards.straightdope.com/t/garden-work-weeds-in-walkway-cracks/498517/29 "2009-06-03T16:41:57Z")
> [@filling\_pages](#): > > My dad uses the blow torch method. There are several up sides to this, the main one being that _he gets to play with a freakin’ blow torch_! Much more fun than boiling water. > > Oh, and in reference to the last post: the one dad has doesn’t feature “cute little flames” - when he cranks it up, that baby really roars. It’ll light a bonfire in no time flat, even when it’s been wet out. I have a special tool that has a sharp end with a hook to get into cracks to remove weeds. I’m not keen on carrying boiling water all the way from my kitchen to the site, but we have a blow torch used for creme brulee, and that application sounds like fun. I don’t want to use Roundup in the back because of the dogs. ---
**Author:** ![Improvisor](https://avatars.discourse-cdn.com/v4/letter/i/50afbb/32.png) [@Improvisor](https://boards.straightdope.com/u/Improvisor)\ **Post date:** [June 3, 2009, 6:09pm UTC](https://boards.straightdope.com/t/garden-work-weeds-in-walkway-cracks/498517/30 "2009-06-03T18:09:16Z")
I don’t recommend using salt. I used it on our brick patio, and it did kill all the weeds between the cracks, but after a rain storm or two the salt leached out and wound up killing about a foot of grass all around the patio, too. Don’t know if I used too much salt or if I have bad drainage under my patio and the salt didn’t drain directly down. I’ve used the boiling water method as well. It works fine, but does get to be a pain in the a\*\* for larger areas. Currently I just weed-wack them down every couple of weeks to get the lazy-man’s “rustic English cottage walkway” look. Much easier. 🙂 ---
**Author:** ![Casserole](https://avatars.discourse-cdn.com/v4/letter/c/b77776/32.png) [@Casserole](https://boards.straightdope.com/u/Casserole)\ **Post date:** [June 3, 2009, 8:31pm UTC](https://boards.straightdope.com/t/garden-work-weeds-in-walkway-cracks/498517/31 "2009-06-03T20:31:07Z")
> [@chacoguy420](#): > > Gasoline will kill pretty much anything. It’ll kill my wallet too 🙂 Words can’t express how poor I am. In other news, I tried the boiling water method yesterday, and it worked like a charm. The little weeds dried up and I applied a second splash today to kill off the rest. I don’t have an awfully big kettle, though, so I’ve only been able to eradicate about a quarter of the weeds on my walkway… at any rate, hoorah! Thanks everyone! ---
**Author:** ![foolsguinea](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/foolsguinea/32/14751_2.png) [@foolsguinea](https://boards.straightdope.com/u/foolsguinea)\ **Post date:** [June 3, 2009, 10:32pm UTC](https://boards.straightdope.com/t/garden-work-weeds-in-walkway-cracks/498517/32 "2009-06-03T22:32:39Z")
> [@levdrakon](#): > > I’ve heard full strength bleach, but I tried it on some grass and it didn’t do much. I’ve also heard of using gin. I think the juniper berry is what does it. I doubt it. Probably the alcohol. (Lives in a town full of junipers.) [Previous page](https://boards.straightdope.com/t/garden-work-weeds-in-walkway-cracks/498517.md?page=1)