Does copper tape stop slugs and snails? Here’s the video evidence…

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hungry snails

Allium crazy snails

It’s that time of year when slugs and snails creep out of the woodwork (quite literally) and look for sources of food after their winter hibernation. My alliums are currently being ravaged and I’m out in the garden with a torch at 10pm on most evenings removing the hungry little beasts. Last year I conducted some tests to disprove the value of egg shells, pistachio nut shells, hair and chilli powder in preventing slugs and snails from eating our plants, all were easily crossed by snails. Young chopped brambles were a surprise snail barrier success though.

This year I’ve heard a lot about copper slug and snail barriers, copper alloy has some unique properties, it is naturally anti-microbial – it kills bacteria and viruses, from E. coli and flu to the super bug MRSA [1] (within a few hours of contact). Could this somehow be why copper works as a snail barrier? Well no… but here I explain more about snails and their relationship with copper. I have of course conducted a series of new time lapse snail vs. copper tape tests to see if it’s worth buying expensive copper tape…

Why should copper work as a slug and snail barrier anyway?

As members of the Mollusca group of animals, slugs and snails use Hemocyanin proteins in their blood to transport oxygen around their bodies (whereas we mammals use iron based Hemoglobin). These Hemocyanin proteins contain two copper atoms. This makes all molluscs very sensitive to the ingestion of additional quantities of copper. Too much copper and it prevents oxygen from moving around their bodies and they eventually die, unless they flee to safety.

Copper sulphate has been a common snail control method for a long time, it’s quite commonly used in aquatic situations where water snails have become a problem in the farming of fish[2] or growing rice[3]. There is no doubt therefore that copper alloy should make a slug or snail very nervous when confronted with a barrier of the shiny metal stuff.

Electric Nonsense

Static Electric Nonsense

Whilst many copper slug and snail barrier products claim ‘a small static shock will be deliveredthis is unproven nonsense that has been passed on from manufacturer to manufacturer as the best way to sell the copper tape’s benefits. Mildly electrocuting those pesky gastropods sounds nice doesn’t it after what they’ve done to your poor plants?! It’s good for sales but is probably NOT what is happening (there isn’t any evidence available and I have asked for it to no avail). Snail slime / mucous contains two acids: glycolic acid and hyaluronic acid – both of which have been used in skin care (for smooth skin and anti-aging) and the development of modern day products. In ancient Greek times snail mucous was used to treat wounds, burns and abscesses with some success [4]. I propose that the snail slime itself (with its acids) on contact with copper tape reacts with the copper alloy (IF… and that’s a big IF… it’s thick and contains enough copper alloy) to create a foul taste or suffocating effect similar to that of copper sulphate, hence the slug or snail gets a bad taste and then turns back to get a breather.

And then there’s ‘acid rain’

Sulphur Dioxide Levels

Sulphur Dioxide Levels – Click for Full Map

Copper sulphate is made by combining copper alloy with sulphuric acid. Whilst sulphur dioxide emissions from power stations have dropped enormously in Western Europe since the 1980s, there is still enough in the atmosphere for rain to contain traces of sulphuric acid. In certain places within the UK you will be receiving higher doses of sulphuric acid in your rain than others. What happens when this acid rain lands on copper alloy tape on your outdoor plant pots? It makes trace amounts of copper sulphate which runs down your pot and into the soil. I therefore put it to you that as the copper tape weathers, in some areas it releases traces of copper sulphate which makes it even more potent, especially on more porous terracotta pots that can hold onto the copper sulphate. If you live in a city there’s probably more chance of copper tape having this effect than if you live in the countryside. I can’t prove that it exists but it would seem logical.


Does copper tape stop slugs and snails? The Website Reviews

Looking at the product reviews on Amazon it seems that the usefulness of copper tape products sold to gardeners is a little more on the positive side than the negative – 60/40. I personally wonder whether or not the success disparity is caused by the minor geographic acid rain factor (as detailed above) or whether some batches of the copper tape are just badly manufactured or poorly tested before production (if tested at all):

Slug & Snail Barrier Price It Works (4/5 Stars)
Defenders 4m £3.25 60%
Green Blade 4m £2.39 61%
Rentokil 4m £3.14 62%
Doff 4m £4.30 70%

Copper tape DOESN’T work! (40%)

 

 

 

 

Copper tape DOES work! (60%)

 

 

 

 

 

 

 

My own copper tape vs snails – time-lapse tests!

TEST 1 DOFF Copper Slug Tape (2.3 cms wide) – SNAIL FAIL!

TEST 2 DOFF Copper Slug Tape (2.3 cms wide) – SNAIL FAIL!

TEST 3 VITAX Copper Slug Tape (2.3 cms wide) SNAIL FAIL!

TEST 4 GROWING SUCCESS Slug Barrier (2.8 cms wide) SNAIL FAIL!

Having decided that the copper tapes being sold in garden centres and the likes of Robert Dyas was just inferior and not suitable for the purpose for which they were purchased BUT given that people swear by copper tape I decided to look for a serious solution. I settled on electric guitar shielding tape from Six String Supplies Ltd for £7.45 (3 metres) and my word is this tape the business! It feels like copper alloy and is MUCH wider (5 cms) than the absolute rubbish being sold as a horticultural barrier:

TEST 1 Electric Guitar Shielding Tape (5 cms wide) SNAIL REPELLED!

TEST 2 Electric Guitar Shielding Tape (5 cms wide) SNAIL REPELLED!

In Conclusion

Copper DOES work as a slug and snail barrier if the percentage of copper alloy is high enough and the width is in excess of 4 cms. Don’t waste money on any of the other ‘gardening’ products tested above and be cautious of using anything else that comes in a similar sized box (or from a matching production line…).

As it happens most of my slug and snail problems are not pot related but allotment related. For that the boy and I have come up with a handy solution that will re-use plastic with electric guitar insulating tape AND provide protection to all of our allotment seedlings this year (in particular sunflowers, runner beans and squash):

RECYCLE PLASTIC AND MAKE YOUR OWN COPPER RINGS!
(A 7 year old camera man sorry about that…)


References

  1. Copper destroys MRSA at a touch
  2. Uniform Application of Copper Sulfate as a Potential Treatment for Controlling Snail Populations in Channel Catfish Production Ponds
  3. Efficacy and environmental fate of copper sulphate applied to Australian rice fields for control of the aquatic snail Isidorella newcombi
  4. Helix and Drugs: Snails for Western Health Care From Antiquity to the Present

 

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About Author

Matt Peskett is GrowLikeGrandad (if you want to know why read 'About the Editor). He has a few 'heavy clay' allotments and is Chairman of the Dorking Allotment Holders Association (DAHA). Matt also has a medium sized 'sandy soil' hillside garden (Italian terrace designed) and enjoys photography - especially nature. Matt takes inspiration from gardens like Hidcote and Great Dixter and enjoys watching anything on TV presented by Monty Don or Louis Theroux.

29 Comments

  1. Thanks for taking the time to research & test these – very interesting results, and I hadn’t considered the rain factor before.

    Out of interest, did you try stacking two lengths of the smaller tape (so the test 4 product would result in a 5.6cm barrier for example) to see if it really is the width or whether something else is in play?

    I’m seeing a pattern overall recently – add the word ‘horticultural’ or ‘gardeners’ to a product & bump up the price. It’s the same story with netting – replace the word ‘horticultural’ with ‘scaffolders’ and get a superior product for a fraction of the price.

    • Deborah Hosking on

      HI Lee, I was thinking the same, but then reading it again I think the percentage of copper alloy is still the problem with test 4? You’re right on about the scaffolders netting. I’m using some right now – just got to double up/cover the line of holes that the scaffold poles would go through – so much cheaper.

  2. I bought some ground bran. Put it in little heaps around the garden and under plants. The next morning my garden was covered in birds eating the slugs and snails. They gorge on bran and when they have eaten their fill they are too full to move. Literally as it expands inside them!! They are stuck and cannot move. The birds and hedgehogs etc get an eco friendly breakfast!! Try it, it really woks!! Available from health food stores and anywhere they sell loose bran.

  3. Excellent work, thank you both. I want to stop slugs getting to the food I put out for hedgehogs and this is ideal. Slugs are harmful to hedgehogs as they carry lungworm.

  4. Thank you very much for this, really helpful and interesting. I tried the garden centre copper tape and apart from pausing to wave at me as they slid over, the tape made no difference to the snails at all. I’ll go and get some guitar tape and give it a try immediately. And well done to the cameraman, he did a great job

  5. I just started researching slug control as they decimated my new veggie patch last week. I had thought the idea with copper wire was to used it to make an actual electric fence, with a battery. Has anyone here tried that?

  6. I’m so chuffed I found this piece of yours! Ha fantastic! Really appreciate the time you’ve taken on the copper tape to pass it on to everyone .How generous of you .Saving us time effort and much needed cash ..I too love anything with Monty Don and sobbed last night after watching Gardeners World to hear Nigel had passed away.
    Thank you for this
    Tracy.

  7. Thanks for taking the time to do this experiment and share the results. I was just about to buy cheap copper tape but will look at the guitar tape instead. Thanks again and happy gardening!

  8. Great stuff. I bought 4″ wide EMI tape, slapped it on my pots, and haven’t had a bite since!
    My plants are loving it, and no more blue pellets!!

  9. I got very frustrated with slugs/snails munching every bit of new growth on my clematis/climbers. I accidently found a spray of very dilute (1/10 prob) listerene mouthwash kept them at bay. I sprayed everything…fence,wall,plant(lightly), ground. The foliage seemed unaffected, but all else had failed so now its established fingers crossed for springtime. Of course rain does wash it away but it’s so cheap, I use an empty surface spray bottle,…pennies. Greenfly too.

  10. Copper DEFINITELY works in repelling slugs and snails. However.. forget that silly tape stuff. What you have to do is purchase a few quids worth of copper nuts and bolts or workshop offcuts, then open up some 12 bore cartridges and replace the shot, with the copper pieces… One shot, at a range of 1 to 2 inches will repel ANY slug. It`s extremely effective, but does produce a fair amount of collateral damage.. 🙁

  11. I’m trying an experiment this year with landscaping fabric, spray glue and copper powder (atomised copper). That way I should be able to make copper mats of any size or shape required. I’ll report back regarding success or failure.

  12. “Copper DOES work as a slug and snail barrier if the percentage of copper alloy is high enough and the width is in excess of 4 cms.”

    What percentage should it be at least? Do you mean the percentage of the copper itself? What brand and online store would you recommend going to? Many thanks.

  13. Thanks SO much for this. I’ve tried the copper tape from the garden centres and they’re pointless. Slugs and snails are literally the bane of my life right now, especially with all the rain we’re getting. Will try this!

  14. Bertie Duggah on

    Hi. I’m thinking of making simple planter stands from copper pipe, say 10 or 15mm. This raises the planter but also creates a copper barrier over which the slug or snail has to cross. Think it will work?

  15. I have just spent a wonderfully productive – if slightly yucky – hour around the garden after overnight rain, picking about 100 – yes 100! – slugs off my plants – chiefly potatoes. Slug traps – don’t waste good beer! Sugar, dried yeast, flour mixed to a thin slurry in cold water – work quite well but better in drier weather. When it’s wet the beasts go straight for the plants!

  16. David Edward Pratt on

    The reason a lot of slug tapes don’t work is the marketing people lacquer it to keep it shiny which also protects the slugs from the copper.

  17. Thank you for sharing this. I almost bought some snail tape until I saw these vids, I appreciate when people share such useful information online like this. Also fulfils my curiosity to see slugs fail to cross the barrier.

  18. Thank you so much for your fun and interesting research! I made my own slurry flour, sugar and yeast. I use sluggish and still lose half the crop to those slugs! Going to try this . Hopefully everything all together will help keep those slugs outside my garden perimeter

  19. Johan Veldhuijsen on

    you can put 2 small copper rings around it with tape and solder 2 wires with 9v battery to it, it does not kill the snail but it will never past over it.

    • Sheila Bishop on

      Very interesting! I have huge in-ground hostas and was wondering if there was a way to use copper because surely tape wouldn’t work. I’m going have to try something, ANYTHING at this point to rid my garden of these pesky slugs!!

  20. I stopped slugs getting to my potted Hosta’s by smearing a layer of Vaseline round the top edge of the pots, this works extremely well, just got to make sure the leaves don’t touch the ground or other plants !

  21. Tanya reynolds on

    Thank you so much for taking the time to post this information. So useful. And also to all those adding further useful comments. Gardeners are such generous people 😉

  22. Sheila Bishop on

    Thank you so much for your time in this experiment! I have been wondering what it might look like to see a snail or slug try to cross the copper and now I know!

  23. Yup you’re absolutely correct, copper tape does not work at all! I tried it a couple of days ago on my planters and there you go…slugs were in my planter the next day eating my green pepper seedlings!

  24. Duncan Hammett on

    I’ve put the recommended copper tape around my pots. How long does it last outdoors, exposed to the elements?

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