Copper Tape

[Deb London]

Found a very solid copper tube about 15 cm across a few years back. Cut it into 4 with a hacksaw. Nothing ever crosses these "collars". No batteries needed at all, although, depending on the plant, the plants sometimes touch the ground to form a bridge. Until that point they are completely safe. So yes, worth scouting around for freebies.

[Jim Ford]

Myself and others have found that copper only is not an effective deterrent to slugs. A couple of years ago I was forwarded correspondence by someone that experimented with using a copper+zinc couple to see if the combination of slug+copper+zinc would create a electrical cell to deter the slugs with a small generated voltage. It didn't work! I also found a paper by a field worker in Hawaii that carried out similar experiments to protect rare plants. Again the conclusion was that copper on its own was ineffective. I don't have the paper to hand, but the following are the emails I was forwarded (I've 'asterisked' the names out because I haven't sought permission from the correspondents):

From: ****
Sent: 02 July 2007 22:05
To: ****
Subject: Re: Zinc tape and slugs

Hi ****,

Thank you very much for the sample of self-adhesive zinc tape a while
back. I have had a slate with a strip of copper running all around it to
form a rectangle within a similar rectangle formed from the zinc tape
with a gap of about 6mm between them.

I have known for a while that copper strip makes no difference to slug
behaviour, the idea possibly arose as copper compounds are a molluscan
toxin; elemental copper appears to worry them not a jot. Adding the zinc
should form a 1.3(ish)V cell with the slug providing the electrolyte and
should give a sufficintly high jolt to make them retreat. I have watched
slugs crawl from one side of the slate to the other without flinching.
As I said before, the polysaccharide mucus is essentailly non-conductive
so no cell is formed.

I am therefore confident to conclude that the use of Cu, Zn or Cu/Zn is
absolutely useless at stopping these damned molluscs from munching their
way through my garden.

Case closed.

Best wishes

****


Hi ****,

I have done some preliminary checks and slugs appear to not be
too bothered about crawling across elemental copper or zinc or a
potential electric cell of copper zinc and slug. I did a quick check on
the electrical conductivity of a slug and it is up in the MOhm range,
probably because the mucus is a polysaccharide an intrinsically non
conductive. I will continue, I can do no worse than the suggestion by
purveyors of copper tape that slugs get a shock off it; interesting as
they only supply one electrical pole that shares the same earth point as
the slug!

Many thanks for your help, as I say, I haven't given up yet.

****

Jim

[Deb London]

I am truly puzzled by this, as I would almost swear that copper works in our garden. I have run out of the tape in the past, and the snails will invade the tub/pot without copper, not the ones with copper.

The collars have never failed once. Even near the pond (AKA Snailsville).

[basquesteve]

As you stated you have staging in the greenhouse put each leg in a bucket of water the same with the pots raise them above above the water level in a pot tray I have never seen a slug swim, worked well for me in the past

[Paul mabbott]

Originally Posted by basquesteve

As you stated you have staging in the greenhouse put each leg in a bucket of water the same with the pots raise them above above the water level in a pot tray I have never seen a slug swim, worked well for me in the past

I've seen them swim/crawl out of water but never voluntarily try to cross it! Just to be more effective, add a drop of washing-up liquid or other detergent into each cup.

[DoraMac]

Thanks folks for all the information - lots of ideas to consider.

DMac

[Deb London]

I think my picture supports the use of copper as a deterrent. This is a Ramsons plant in my garden. Several days ago now the first two emergent leaves were attacked, probably by a snail (there are few slugs here, but I don't know for sure). I grabbed a copper collar and threw it over the plant. The leaves that they started eating have remained untouched since the collar was put in place. The leaf on the right has emerged since, and has not been damaged (yet?).



Of course, there could be many reasons for this. But this sort of protection has happened time and again following the use of these copper collars in my garden. I rely on them.

[Jim Ford]

Originally Posted by Deb London

Of course, there could be many reasons for this. But this sort of protection has happened time and again following the use of these copper collars in my garden. I rely on them.

Perhaps the slugs haven't read the internet findings that copper on its own doesn't work!

;^)

Jim

[DoraMac]

Originally Posted by Jim Ford

Perhaps the slugs haven't read the internet findings that copper on its own doesn't work!

;^)

Jim

Well, I'm just going to try and find out - soon.