# Can I "salt the earth" to prevent weeds? **URL:** \ **Category:** Factual Questions\ **Created:** [October 29, 2009, 3:01pm UTC](https://boards.straightdope.com/t/can-i-salt-the-earth-to-prevent-weeds/515611 "2009-10-29T15:01:53Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Mooch](https://avatars.discourse-cdn.com/v4/letter/m/7bcc69/32.png) [@Mooch](https://boards.straightdope.com/u/Mooch)\ **Post date:** [October 29, 2009, 3:01pm UTC](https://boards.straightdope.com/t/can-i-salt-the-earth-to-prevent-weeds/515611/1 "2009-10-29T15:01:53Z")
I was thinking about throwing down an assload of salt on a 12’X12’ little flagstone patio in the corner of my yard to prevent the weeds that grow up between the stones during the spring and summer. Would I need so much salt that it would be ridiculous? Would it even work? Would it be dangerous to my dog? Would I have to change my name to Moochicles (Mooch-i-cleez)? Yes, I’m a lazy dude. ---
**Author:** ![Arkcon](https://avatars.discourse-cdn.com/v4/letter/a/96bed5/32.png) [@Arkcon](https://boards.straightdope.com/u/Arkcon)\ **Post date:** [October 29, 2009, 3:11pm UTC](https://boards.straightdope.com/t/can-i-salt-the-earth-to-prevent-weeds/515611/2 "2009-10-29T15:11:49Z")
Briefly, the scholarly information on the subject suggests no. > **[Did ancient conquerors punish their enemies by sowing captured fields with salt?](https://www.straightdope.com/21343814/did-ancient-conquerors-punish-their-enemies-by-sowing-captured-fields-with-salt)** ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [October 29, 2009, 3:23pm UTC](https://boards.straightdope.com/t/can-i-salt-the-earth-to-prevent-weeds/515611/3 "2009-10-29T15:23:29Z")
Don’t need table salt. There are plenty of herbicides with staying power. click [here;](http://www.scotts.com/smg/catalog/productCategoryLanding.jsp?navAction=jump&branPage=ortho&itemId=cat50036&id=cat50008) check out the patio stuff and the driveway stuff, see which one is most appropriate for your situation. I used to have a gravel driveway and sprayed it with this stuff a couple of times a year; worked great. ---
**Author:** ![kopek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kopek/32/337_2.png) [@kopek](https://boards.straightdope.com/u/kopek)\ **Post date:** [October 29, 2009, 3:42pm UTC](https://boards.straightdope.com/t/can-i-salt-the-earth-to-prevent-weeds/515611/4 "2009-10-29T15:42:09Z")
Rock salt doesn’t work too badly and if you wait for the end of winter sales in northern states, its pretty cheap too. Don’t know about if it bothers pets though. ---
**Author:** ![lieu](https://avatars.discourse-cdn.com/v4/letter/l/c2a13f/32.png) [@lieu](https://boards.straightdope.com/u/lieu)\ **Post date:** [October 29, 2009, 3:45pm UTC](https://boards.straightdope.com/t/can-i-salt-the-earth-to-prevent-weeds/515611/5 "2009-10-29T15:45:50Z")
Someone left one of [these](http://www.mortonsalt.com/products/foodservice/tablesalt2.html), a 4 lb. box of table salt on my neighbor’s lawn this summer. There’s now a bare patch where St. Augustine used to grow, probably 2’ x 4’. If the two are related, and I think they are since he’s threatened a number of women, children and pets in the neighborhood, then yes, salt works very well to discourage growth of your average vegetation. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [October 29, 2009, 4:36pm UTC](https://boards.straightdope.com/t/can-i-salt-the-earth-to-prevent-weeds/515611/6 "2009-10-29T16:36:11Z")
> [@Mooch](#): > > I was thinking about throwing down an assload of salt on a 12’X12’ little flagstone patio in the corner of my yard to prevent the weeds that grow up between the stones during the spring and summer. > > Would I need so much salt that it would be ridiculous? Would it even work? Would it be dangerous to my dog? Would I have to change my name to Moochicles (Mooch-i-cleez)? > > Yes, I’m a lazy dude. salt would stain the stone. salt would be bad for dog to ingest and an irritant to paws. herbicide with glyphosate (a plant enzyme inhibitor) is nontoxic to people and animals. does a great job of plant killing and not harmful otherwise if used properly. it is the safest commercial herbicide a person could use for plant purposes. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [October 29, 2009, 5:39pm UTC](https://boards.straightdope.com/t/can-i-salt-the-earth-to-prevent-weeds/515611/7 "2009-10-29T17:39:09Z")
I’ve used [Borax](http://www.extension.umn.edu/yardandgarden/ygbriefs/h519borax.html) to control errant trumpetvine sprouts near my patio edges. It’s nice in that the boron tends to stay where you put it. ---
**Author:** ![Mooch](https://avatars.discourse-cdn.com/v4/letter/m/7bcc69/32.png) [@Mooch](https://boards.straightdope.com/u/Mooch)\ **Post date:** [October 29, 2009, 6:16pm UTC](https://boards.straightdope.com/t/can-i-salt-the-earth-to-prevent-weeds/515611/8 "2009-10-29T18:16:44Z")
> [@johnpost](#): > > salt would stain the stone. salt would be bad for dog to ingest and an irritant to paws. > > herbicide with glyphosate (a plant enzyme inhibitor) is nontoxic to people and animals. does a great job of plant killing and not harmful otherwise if used properly. it is the safest commercial herbicide a person could use for plant purposes. Thanks - I’ll give it a try this spring. I’ll have to get all Roman on my yard in another way. ---
**Author:** ![Sunspace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sunspace/32/1250_2.png) [@Sunspace](https://boards.straightdope.com/u/Sunspace)\ **Post date:** [October 29, 2009, 6:34pm UTC](https://boards.straightdope.com/t/can-i-salt-the-earth-to-prevent-weeds/515611/9 "2009-10-29T18:34:19Z")
Isn’t it easier just to put a layer of plastic under the patio stones? ---
**Author:** ![billfish678](https://avatars.discourse-cdn.com/v4/letter/b/7bcc69/32.png) [@billfish678](https://boards.straightdope.com/u/billfish678)\ **Post date:** [October 29, 2009, 6:36pm UTC](https://boards.straightdope.com/t/can-i-salt-the-earth-to-prevent-weeds/515611/10 "2009-10-29T18:36:32Z")
Start a garden there. Nothing will grow there ever again. Works even better if you put a bunch of expensive tomato plants there. ---
**Author:** ![Mooch](https://avatars.discourse-cdn.com/v4/letter/m/7bcc69/32.png) [@Mooch](https://boards.straightdope.com/u/Mooch)\ **Post date:** [October 29, 2009, 6:38pm UTC](https://boards.straightdope.com/t/can-i-salt-the-earth-to-prevent-weeds/515611/11 "2009-10-29T18:38:52Z")
> [@Sunspace](#): > > Isn’t it easier just to put a layer of plastic under the patio stones? These stupid little weeds grow in the limestone screen between the rocks and above the landscape fabric. Plus it’s over 1 ton of stone. Did I mention I am a lazy dude? ---
**Author:** ![dracoi](https://avatars.discourse-cdn.com/v4/letter/d/90db22/32.png) [@dracoi](https://boards.straightdope.com/u/dracoi)\ **Post date:** [October 29, 2009, 6:41pm UTC](https://boards.straightdope.com/t/can-i-salt-the-earth-to-prevent-weeds/515611/12 "2009-10-29T18:41:54Z")
> [@Sunspace](#): > > Isn’t it easier just to put a layer of plastic under the patio stones? I don’t know why people keep recommending this. It may block out the old weeds and keep them from growing up, but within a few months, enough dirt has blown in on top of the plastic to let new weeds grow. ---
**Author:** ![Tom\_Tildrum](https://avatars.discourse-cdn.com/v4/letter/t/e95f7d/32.png) [@Tom\_Tildrum](https://boards.straightdope.com/u/Tom_Tildrum)\ **Post date:** [October 29, 2009, 6:44pm UTC](https://boards.straightdope.com/t/can-i-salt-the-earth-to-prevent-weeds/515611/13 "2009-10-29T18:44:38Z")
> [@johnpost](#): > > salt would stain the stone. salt would be bad for dog to ingest and an irritant to paws. > > herbicide with glyphosate (a plant enzyme inhibitor) is nontoxic to people and animals. does a great job of plant killing and not harmful otherwise if used properly. it is the safest commercial herbicide a person could use for plant purposes. We don’t know where the OP is. Don’t some countries (those of the EU, for instance) ban glyphosate? ---
**Author:** ![Mooch](https://avatars.discourse-cdn.com/v4/letter/m/7bcc69/32.png) [@Mooch](https://boards.straightdope.com/u/Mooch)\ **Post date:** [October 29, 2009, 7:28pm UTC](https://boards.straightdope.com/t/can-i-salt-the-earth-to-prevent-weeds/515611/14 "2009-10-29T19:28:27Z")
> [@Tom\_Tildrum](#): > > We don’t know where the OP is. Don’t some countries (those of the EU, for instance) ban glyphosate? Chicago - I think it’s cool here. ---
**Author:** ![Anne\_Neville](https://avatars.discourse-cdn.com/v4/letter/a/b9e5f3/32.png) [@Anne\_Neville](https://boards.straightdope.com/u/Anne_Neville)\ **Post date:** [October 29, 2009, 8:06pm UTC](https://boards.straightdope.com/t/can-i-salt-the-earth-to-prevent-weeds/515611/15 "2009-10-29T20:06:31Z")
> [@johnpost](#): > > herbicide with glyphosate (a plant enzyme inhibitor) is nontoxic to people and animals. does a great job of plant killing and not harmful otherwise if used properly. it is the safest commercial herbicide a person could use for plant purposes. I spray Roundup, which is an herbicide with glyphosate, on the weeds that come up in the cracks between my patio stones. It doesn’t, at least in my experience, do much to keep the weeds from coming up. It does do an admirable job of killing them when they do, but I’d rather have some way to keep them from coming up in the first place. That way, I wouldn’t have to look at them for a couple of weeks and think “You know, I really should do something about those weeds in the patio”. I’d be much happier if there were some way of keeping there from ever being weeds that I have to deal with. It would be really nice if it didn’t involve me having to bend over the patio and spray stuff on all the cracks- doing that makes my back hurt. ETA: I’m at least as lazy as **Mooch** , probably lazier, so the less effort and attention required, the better ---
**Author:** ![Sunspace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sunspace/32/1250_2.png) [@Sunspace](https://boards.straightdope.com/u/Sunspace)\ **Post date:** [October 29, 2009, 8:18pm UTC](https://boards.straightdope.com/t/can-i-salt-the-earth-to-prevent-weeds/515611/16 "2009-10-29T20:18:03Z")
> [@dracoi](#): > > I don’t know why people keep recommending this. It may block out the old weeds and keep them from growing up, but within a few months, enough dirt has blown in on top of the plastic to let new weeds grow. That’s true too. And it would mess up water drainage. Advice rescinded. 🙂 ---
**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:** [October 29, 2009, 8:37pm UTC](https://boards.straightdope.com/t/can-i-salt-the-earth-to-prevent-weeds/515611/17 "2009-10-29T20:37:34Z")
> [@Anne\_Neville](#): > > I spray Roundup, which is an herbicide with glyphosate, on the weeds that come up in the cracks between my patio stones. It doesn’t, at least in my experience, do much to keep the weeds from coming up. It does do an admirable job of killing them when they do, but I’d rather have some way to keep them from coming up in the first place. True, and there’s the rub. Glyphosate is safe (as far as herbicides go) but only works on weeds that are actively growing when its applied. If you’re looking for something that will kill the next batch of weeds, and the one after that, and the one after that, you need something with persistence. Unfortunately persistence also means whatever you put down stays there, and has the chance to run into your local stream or pollute the groundwater. I’d stay away from either salt or fertilizer (massive amounts will kill), because they’ll most likely wash off the patio and into your yard, and wreak havoc on stuff you don’t want to hurt. For something like a 12 x 12 size, The easiest, least environmentally harmful solution might be to get yourself a little propane torch and flame the suckers every time you see something pop up. ---
**Author:** ![johnpost](https://avatars.discourse-cdn.com/v4/letter/j/f17d59/32.png) [@johnpost](https://boards.straightdope.com/u/johnpost)\ **Post date:** [October 29, 2009, 8:52pm UTC](https://boards.straightdope.com/t/can-i-salt-the-earth-to-prevent-weeds/515611/18 "2009-10-29T20:52:30Z")
> [@Anne\_Neville](#): > > I spray Roundup, which is an herbicide with glyphosate, on the weeds that come up in the cracks between my patio stones. It doesn’t, at least in my experience, do much to keep the weeds from coming up. It does do an admirable job of killing them when they do, but I’d rather have some way to keep them from coming up in the first place. That way, I wouldn’t have to look at them for a couple of weeks and think “You know, I really should do something about those weeds in the patio”. I’d be much happier if there were some way of keeping there from ever being weeds that I have to deal with. It would be really nice if it didn’t involve me having to bend over the patio and spray stuff on all the cracks- doing that makes my back hurt. > > ETA: I’m at least as lazy as **Mooch** , probably lazier, so the less effort and attention required, the better as mentioned it only works on growing plants. if you can see a green plant then you can kill it with that. a hand squeeze bottle is hard to use both for effort and distance you need to be. for a large area a 1 gallon air pump sprayer with wand on a hose is nice. it reaches a distance though you have to watch for spray drifting to not get on other plants. for a small far away target you could try painting it on. a fine holed sponge on a stick will work. i think there are store bought applicators also, a hollow tube with a fine holed sponge on the end. get the leaves wet and you’re good. ---
**Author:** ![dynamitedave](https://avatars.discourse-cdn.com/v4/letter/d/ed655f/32.png) [@dynamitedave](https://boards.straightdope.com/u/dynamitedave)\ **Post date:** [October 29, 2009, 10:15pm UTC](https://boards.straightdope.com/t/can-i-salt-the-earth-to-prevent-weeds/515611/19 "2009-10-29T22:15:14Z")
If DuPont’s Escort is available in your area, mix in a few grams with the glyphosate. I think the rate for a litre sized garden sprayer would be 1 gram. I’d use 5 grams per 100 litres, but that’s using high pressure, high volume spray rigs. In my experience, the Escort/glyphosate combination seems to kill everything and the Escort stays in the soil for about 3 months preventing regrowth. It is safe to use with normal spraying precautions. But read the data to be sure. ---
**Author:** ![Anne\_Neville](https://avatars.discourse-cdn.com/v4/letter/a/b9e5f3/32.png) [@Anne\_Neville](https://boards.straightdope.com/u/Anne_Neville)\ **Post date:** [October 30, 2009, 1:30pm UTC](https://boards.straightdope.com/t/can-i-salt-the-earth-to-prevent-weeds/515611/20 "2009-10-30T13:30:31Z")
> [@kunilou](#): > > The easiest, least environmentally harmful solution might be to get yourself a little propane torch and flame the suckers every time you see something pop up. That would certainly get points for being fun and cool, too. [Next page](https://boards.straightdope.com/t/can-i-salt-the-earth-to-prevent-weeds/515611.md?page=2)