Crushed seashells should be so sharp-edged that snails will not want to crawl over them.
It might make sense, therefore, to lay crushed seashells out on the paths around beds, for example, or to use them to build up small protective walls around endangered plants and beds.
But even this remedy is very controversial. I have not tested it yet.
21 thoughts on “Mulch Barriers to Protect Plants Against Snails and Slugs: Do They Work?”
I tried wood ashes, once, on clay soil. Figuring their effectiveness would diminish after the first rain, I covered the ashes with black plastic. I think I got good slug protection. However, my tomato plants grew six feet tall before blooming and didn’t produce much fruit in my northern location with a short growing season.
I have used the Beer Trap successfully – It traps and humanely kills snails and slugs. Put a shallow saucer or container in the garden and dig in so it is level with the top of the soil. Fill with beer, the snails and slugs love the yeast. I put a few of these containers around the patch and empty out the dead mollusks and top up with fresh beer daily for as long as necessary.
Dear Colleen, thank you for your comment. But beer traps are dangerous not only for slugs, but for many other species in the garden – including snail killing beetles and hedgehogs. Further, the yeast often attracts snails and slugs from all around your area into your garden. More info here: The beer trap dilemma. May you find peaceful means to protect your plants. Kind regards, Alex
I have recently used sheep’s fleece which has been fairly effective although each plant needs a collar of it, also wee sluglets still come up inside the collar. We also put empty bottles which have pasted on labels near the vegetables and tomato plants as the slugs and snails feast on the labels which presumably have been stuck on with a ‘tasty’ glue!!! Also corrugated cardboard seems to also be equally attractive!
I find it somewhat humorous that diatomaceous earth was avoided by the author because “Even people who inhale diatomaceous earth can get sick.” Yes, inhaling any fine dust can make a person ‘sick’ in the same way. Inhaling fine dust of any kind isn’t good for people’s lungs, but there’s nothing poisonous about diatomaceous earth, and it can’t make you sick like a poison does. I’m very disappointed that the author didn’t try it because they were fearful they might inhale some. Kind of silly considering all the other dusts people are exposed to on a regular basis. Ever spray paint? You’ve inhaled the fumes. A little won’t really hurt you, but you should do it outside so you don’t inhale a whole lot – but you’ll still inhale some. Cool how we don’t worry about it, even though it’s really dangerous. Same thing. Use caution and common sense. Don’t apply diatomaceous earth when it’s windy, for example. BTW – ‘dusting’ large animals (dogs, goats, etc.) with diatomaceous earth will kill fleas and lice. And again, as long as you don’t make a huge dust cloud while doing it, it’s completely safe for the animals and you.
As I started reading, I noticed diatomaceous earth was on the list at the top, and I was eager to find out how well it compared to the others. Imagine my surprise when the author DIDN’T EVEN TRY IT!!!! (Why even mention it then, and put it on the list!?!) And their reason for not trying it? Because “Even people who inhale diatomaceous earth can get sick.” What is that supposed to mean? “EVEN people … can get sick.” Diatomaceous earth doesn’t make snails, slugs, and other creepy crawlies “get sick” at all!! It scratches their outer bodies, making them dehydrate and die. BIG difference! Because of how it works people shouldn’t inhale the dust, but handling it is just as safe as handling dirt! (Dirt is actually more dangerous because of pathogens that live in it!) People and animals even eat diatomaceous earth – it’s used as a ‘flowing agent’ in some foods, and the FDA doesn’t require it to be placed on the label! Seriously? “EVEN people … can get sick.” ! ? ! ?
Obviously you should avoid making a dust cloud while using it, which should be avoided with ANY powder used for ANY reason. Our lungs aren’t made for breathing dust. I wonder if the author would have avoided using baby powder if that was something people used for snails & slugs, or if they would have avoided it, saying “EVEN people who inhale baby powder can get sick.” Diatomaceous earth may be an irritant to human lungs, but at least it doesn’t cause cancer like talc does – you know – baby powder?
People who minimize the real risks of using diatomacous earth have apparently not schooled themselves on the facts. See “Health hazards due to the inhalation of amorphous silica” https://www.ncbi.nlm.nih.gov/pubmed/11876495 “People and other mammals should never use the coarse, crystalline form of diatomaceous earth sold for use in swimming pool filters or as insecticides, or sources of diatomaceous earth contaminated with toxins like arsenic and the metal toxins. If inhaled, the crystalline form can cause a disabling lung disease called silicosis” https://www.westonaprice.org/health-topics/environmental-toxins/mad-as-a-hatter/
Not only that, can anyone justify its deadly effects on bees and other pollinators, when their very survival (and ours, if crops are not pollinated) is already threatened?
Food grade diatomaceous earth is not the same as that sold for swimming pool filters and is completely safe. As someone else further up in comments stated, NO powder is good to inhale. Take proper precautions, don’t apply in windy conditions etc. Diatomaceous earth kills fleas, ticks, and other insects by causing their bodies to dry out and they die. It is not going to harm animals or people. Sprinkling it in the soil or around the base of plants is not going to harm bees either.
Did you ever get an opportunity to test damp mint leaves? I scatter aromatic herbs throughout my garden and they seem to help with quite a few things, but I hadn’t tried making a wall of them.
Hello Merbs, thank you for your comment! I didi’t try damp leaves. If the conditions are sufficient I will try them next summer (: Good luck with your garden! Alex
I put a ring of play sand around new plants. Slugs don’t bother them. Need to refresh after a hard rain. I also pick snails in the morning and toss them in a big patch of pig squeek. The snails happily keep the Bergenia in check and don’t seem to migrate back to my veggies.
I cut some bramble branches and put around my lettuce – not a slug or snail in sight!!
how about shredded newspaper? it will get wet during watering but then dry & hardened..any luck with this? slugs/snails/centipeded very bothersome. rsvp
thank you for your comment. Some snails and slugs like to eat newspaper. I don’t believe it is worth trying. If you do – please let me know the results.
Good Luck!
Alex
JT, the diatomacous earth you want to use is called Food Grade. Not the same as for use in swimming pools. Food Grade is a great detox when consumed. On top of snail repellent, it’s also a nutrient for the plants.
I have a mint plant, I am not sure exactly what variety, but when it’s alive the slugs will eat it. Not as much as other plants, but they do eat it, so I am not sure the wet leaves will work. I made a HUGE mistake a few years ago and used bark as mulch everywhere the same year there was a horrible slug infestation in my area, I got rid of the bark but I still have some trouble with slugs. The only thing I have found that really works is the beer traps, but I have to change them twice a day and I don’t always have time for that. I will go out in the evenings around sunset and pick as many as I can find and flush em. If I find them during the day while I am working in the garden I will put them in a pie plate or other container that they can’t climb out of and leave it out for the birds. Robins and magpies love to eat them.
I am trying twigs as a mulch on top of the bark chippings and so far so good. It is sharp and spiky so hopefully will deter slugs and snails and doesn’t get as soggy as some of the other things mentioned. But I have also tried quite large horticultural grit on a lupin in a pot and that seems to be working reasonably well (probably a bit like the crushed sea shells). Slugs and snails are the enemies of poor lupins… hopefully some of these ideas will work and the lupins will thrive (and the bees!)
I also tried various methods, even nematodes and hedgehogs, but what finally worked for me, was to dig a little pond and add some tadpoles. The resulting frogs are doing a brilliant job at keeping the slug population under control 🙂
I tried wood ashes, once, on clay soil. Figuring their effectiveness would diminish after the first rain, I covered the ashes with black plastic. I think I got good slug protection. However, my tomato plants grew six feet tall before blooming and didn’t produce much fruit in my northern location with a short growing season.
I have used the Beer Trap successfully – It traps and humanely kills snails and slugs. Put a shallow saucer or container in the garden and dig in so it is level with the top of the soil. Fill with beer, the snails and slugs love the yeast. I put a few of these containers around the patch and empty out the dead mollusks and top up with fresh beer daily for as long as necessary.
Dear Colleen,
thank you for your comment. But beer traps are dangerous not only for slugs, but for many other species in the garden – including snail killing beetles and hedgehogs. Further, the yeast often attracts snails and slugs from all around your area into your garden. More info here: The beer trap dilemma.
May you find peaceful means to protect your plants.
Kind regards,
Alex
I have recently used sheep’s fleece which has been fairly effective although each plant needs a collar of it, also wee sluglets still come up inside the collar. We also put empty bottles which have pasted on labels near the vegetables and tomato plants as the slugs and snails feast on the labels which presumably have been stuck on with a ‘tasty’ glue!!! Also corrugated cardboard seems to also be equally attractive!
What happened to copper being a great deterrent. Expensive but last forever.
Here you can find more information about copper as a deterrent.
I find it somewhat humorous that diatomaceous earth was avoided by the author because “Even people who inhale diatomaceous earth can get sick.” Yes, inhaling any fine dust can make a person ‘sick’ in the same way. Inhaling fine dust of any kind isn’t good for people’s lungs, but there’s nothing poisonous about diatomaceous earth, and it can’t make you sick like a poison does. I’m very disappointed that the author didn’t try it because they were fearful they might inhale some. Kind of silly considering all the other dusts people are exposed to on a regular basis.
Ever spray paint? You’ve inhaled the fumes. A little won’t really hurt you, but you should do it outside so you don’t inhale a whole lot – but you’ll still inhale some. Cool how we don’t worry about it, even though it’s really dangerous. Same thing. Use caution and common sense. Don’t apply diatomaceous earth when it’s windy, for example. BTW – ‘dusting’ large animals (dogs, goats, etc.) with diatomaceous earth will kill fleas and lice. And again, as long as you don’t make a huge dust cloud while doing it, it’s completely safe for the animals and you.
As I started reading, I noticed diatomaceous earth was on the list at the top, and I was eager to find out how well it compared to the others. Imagine my surprise when the author DIDN’T EVEN TRY IT!!!! (Why even mention it then, and put it on the list!?!) And their reason for not trying it? Because “Even people who inhale diatomaceous earth can get sick.” What is that supposed to mean? “EVEN people … can get sick.” Diatomaceous earth doesn’t make snails, slugs, and other creepy crawlies “get sick” at all!! It scratches their outer bodies, making them dehydrate and die. BIG difference! Because of how it works people shouldn’t inhale the dust, but handling it is just as safe as handling dirt! (Dirt is actually more dangerous because of pathogens that live in it!) People and animals even eat diatomaceous earth – it’s used as a ‘flowing agent’ in some foods, and the FDA doesn’t require it to be placed on the label! Seriously? “EVEN people … can get sick.” ! ? ! ?
Obviously you should avoid making a dust cloud while using it, which should be avoided with ANY powder used for ANY reason. Our lungs aren’t made for breathing dust. I wonder if the author would have avoided using baby powder if that was something people used for snails & slugs, or if they would have avoided it, saying “EVEN people who inhale baby powder can get sick.” Diatomaceous earth may be an irritant to human lungs, but at least it doesn’t cause cancer like talc does – you know – baby powder?
People who minimize the real risks of using diatomacous earth have apparently not schooled themselves on the facts. See “Health hazards due to the inhalation of amorphous silica” https://www.ncbi.nlm.nih.gov/pubmed/11876495
“People and other mammals should never use the coarse, crystalline form of diatomaceous earth sold for use in swimming pool filters or as insecticides, or sources of diatomaceous earth contaminated with toxins like arsenic and the metal toxins. If inhaled, the crystalline form can cause a disabling lung disease called silicosis”
https://www.westonaprice.org/health-topics/environmental-toxins/mad-as-a-hatter/
Not only that, can anyone justify its deadly effects on bees and other pollinators, when their very survival (and ours, if crops are not pollinated) is already threatened?
Food grade diatomaceous earth is not the same as that sold for swimming pool filters and is completely safe. As someone else further up in comments stated, NO powder is good to inhale. Take proper precautions, don’t apply in windy conditions etc. Diatomaceous earth kills fleas, ticks, and other insects by causing their bodies to dry out and they die. It is not going to harm animals or people. Sprinkling it in the soil or around the base of plants is not going to harm bees either.
Did you ever get an opportunity to test damp mint leaves? I scatter aromatic herbs throughout my garden and they seem to help with quite a few things, but I hadn’t tried making a wall of them.
Hello Merbs,
thank you for your comment!
I didi’t try damp leaves. If the conditions are sufficient I will try them next summer (:
Good luck with your garden!
Alex
I put a ring of play sand around new plants. Slugs don’t bother them. Need to refresh after a hard rain. I also pick snails in the morning and toss them in a big patch of pig squeek. The snails happily keep the Bergenia in check and don’t seem to migrate back to my veggies.
I cut some bramble branches and put around my lettuce – not a slug or snail in sight!!
how about shredded newspaper? it will get wet during watering but then dry & hardened..any luck with this? slugs/snails/centipeded very bothersome. rsvp
Hello Anna,
thank you for your comment. Some snails and slugs like to eat newspaper. I don’t believe it is worth trying. If you do – please let me know the results.
Good Luck!
Alex
JT, the diatomacous earth you want to use is called Food Grade. Not the same as for use in swimming pools. Food Grade is a great detox when consumed. On top of snail repellent, it’s also a nutrient for the plants.
I have a mint plant, I am not sure exactly what variety, but when it’s alive the slugs will eat it. Not as much as other plants, but they do eat it, so I am not sure the wet leaves will work. I made a HUGE mistake a few years ago and used bark as mulch everywhere the same year there was a horrible slug infestation in my area, I got rid of the bark but I still have some trouble with slugs. The only thing I have found that really works is the beer traps, but I have to change them twice a day and I don’t always have time for that. I will go out in the evenings around sunset and pick as many as I can find and flush em. If I find them during the day while I am working in the garden I will put them in a pie plate or other container that they can’t climb out of and leave it out for the birds. Robins and magpies love to eat them.
I am trying twigs as a mulch on top of the bark chippings and so far so good. It is sharp and spiky so hopefully will deter slugs and snails and doesn’t get as soggy as some of the other things mentioned. But I have also tried quite large horticultural grit on a lupin in a pot and that seems to be working reasonably well (probably a bit like the crushed sea shells). Slugs and snails are the enemies of poor lupins… hopefully some of these ideas will work and the lupins will thrive (and the bees!)
I also tried various methods, even nematodes and hedgehogs, but what finally worked for me, was to dig a little pond and add some tadpoles. The resulting frogs are doing a brilliant job at keeping the slug population under control 🙂
I have been told that putting snail pellets around can be harmful for blue tongue lizards, which is not good as they love to eat slugs and snails.