What Does Copper do to Slugs?

One of the most common slug deterrents is copper. As gardeners, it’s a solution that’s offered thrown around as a great way to stop slugs from climbing into pots and containers. But what does copper do to slugs when they touch it?

When slugs come into contact with copper, they receive a harmless electric jolt where the copper reacts with the slug’s slime.

Many gardeners find that using copper tape helps to deter slugs. When slugs interact with the copper, it gives them an electrical shock because of the reaction between their slime and the copper.

Using this knowledge is simple. You can purchase copper tape from most DIY stores and garden centres which can then be wrapped around pots, containers, plant stakes and raised beds to stop slugs from getting in.

You can also buy copper collars which are placed around the base of plants susceptible to slug damage. The slug collar acts as a moat around the plant’s base so that a slug can’t get in.

Does Copper Tape Work?

There have been speculations regarding copper and if it works to deter slugs. Is it yet another garden myth? Is it just pure luck whether or not it will work?

Unfortunately, there is no straightforward answer. With many deterrents, it’s a case of trial-and-error and copper tape is no different.

Copper tape may work in your garden, with your particular slug infestation, to protect your range of plants. But, you may also find that copper tape simply doesn’t work and the slugs will happily glide over it.

If you’re already actively fighting a slug infestation, you’ll know how challenging it can be to rid them from your garden without using dangerous chemicals and slug pellets.

However, we would always advise trying as many natural slug repellents first. Copper tape is one of these more natural ways of deterring slugs and it might just work.

A roll of copper tape can be picked up for very little money from my DIY shops so it’s worth trying just in case it works. It’s also quick to apply in the garden, can have an instant impact and it’s easy to see the results.

If you have a particular plant pot that slugs seem to love, then wrap a barrier of copper tape around it and do nothing else. Over the next few days, you’ll either notice a reduction in the damage to that plant or you’ll see no change.

Why Does Copper Deter Slugs?

There are quite a few theories as to why copper might deter slugs. The most common theory is that copper sends a harmless electrical jolt through the slug when its slime comes into contact with the slug.

There are other theories that indicate that copper dries out slugs. When slugs come into contact with copper, it slows down the slime production. Slugs rely on slime because they glide on their slime trail, and without it, they lose the ability to move forward.

There is also a theory that copper affects the appetite of the slug. Any slug which has absorbed copper will have a changed digestive tract.

This means that the affected slug faces difficulty digesting any food it eats and, therefore, does not produce sufficient energy from the food it consumes. As slugs move slowly, they absorb a lot of copper. 

Another simple reason why copper may deter slugs is because of its sharp edges. Slugs do not feel comfortable gliding on sharp objects. Therefore, putting out anything sharp in addition to copper tapes will also help deter snails. 

But, as you have probably determined, these are just theories and no one really knows why slugs may not like coming into contact with copper. If the particular slugs you’re dealing with decide they don’t like copper then you may never really know why.

Summary 

Dealing with slugs in the garden is not easy. There are so many different repellents recommended that it can be hard to know what does and doesn’t work. Copper tape is a common deterrent suggested.

Unfortunately, it might not always work.

As with many deterrents, it’s a case of testing it out in your garden to see if it works. If it does work, do we know what copper does to slugs or not?

There is a theory that it sends a small electric shock through their bodies. There are other theories that suggest it dries them out, ruins their digestive tracts and may simply be too sharp for them to crawl over. Ultimately, no one really knows!