If electric fences work to deter sheep and horses, why shouldn’t they work with slugs and snails?
No creature likes to get an electric shock. This is why many inventors have already designed different products and tried to secure their beds against slugs by an electric fence.
The fences works relatively well, but until now there’ve not been reliable products on the market.
Below, I describe different ways how an electric slug fence can be installed in the good old do-it-yourself fashion.
What do you need to know?
How much will it cost?
What are the (dis)advantages of this method?
- 1 How does an electric slug fence work?
- 2 Build an electric slug fence yourself
- 3 What parts do you need?
- 4 How far should the distance between the tracks be?
- 5 Avoid short circuits
- 6 Advantages of electric slug fences
- 7 Disadvantages in the handling
- 8 Conclusion
- 9 Slug fence electric costs
- 10 Electric slug fence construction manual (DIY update)
- 11 Effective Slug Control Alternatives
How does an electric slug fence work?
The following video shows the functionality of the fences as slug control.
Video: Electric slug fence with copper tapes in the test
(Beware tender hearts: The slug gets a shock for life.)
There is an electric tension between the two parallel copper tapes.
The slug tries to cross and touches both tapes.
Thereby it completes the electric circuit and the slug gets a little shock. Immediately it turns around.
Due to the large distance between the copper tapes of this fence it is apparently still ready for use even in wet conditions.
Build an electric slug fence yourself
It is not easy, but also not to difficult to build an electric slug fence.
But please keep in mind that electricity is dangerous if not handled with care and knowledge.
It could cause fire and physical harm. Therefore it is important to consult an electrician due to safety reasons.
What parts do you need?
For a simple fence you only need copper tape/wire or perforated metal tape combined with a battery (6-9 volt).
Possible material for the two parallel lines:
copper tape or wire
metal tape or wire
If you like to use metal, it should be galvanized and without plastic mantle. Best would be to use stainless steel.
If the fence is long it would be better to use copper which has better electric performance. And the battery will last longer.
There are many different kinds of batteries available. The more Ah (ampere hours) the battery has the more power it holds and the longer it will live before it becomes necessary to recharge.
6 Volts are enough to deter the slugs. 9 Volts also work perfectly but there are less powerful batteries available.
Although often recommended 12 Volts are a bit too much, because this tension is already able to kill tiny snails and slugs.
If the fence kills slugs their dead bodies will attract more slugs into the garden.
Slugs are highly sensitive and able to smell dead animals from far away. And they are cannibals preferring to eat dead relatives.
You should be aware of that and therefore best choose a 6 Volt system.
Means to attach the tracks
For an electric fence as seen in the above video self-adhesive copper tape or perforated tape is nailed, screwed, or glued onto a wooden board or better an insulating plastic base.
To be able to use the self-adhesive copper the surface should be suitable for gluing, otherwise the tape may peel off after some time.
It is also possible to use copper nails to fixate the copper tape on a wooden surface.
If the surface is not suitable it is possible to use special insulating mounting tape, for example if you would like to attach the tape to a metal underground.
Additional parts needed for a solar powered slug fence
An advanced possibility is to use also a solar cell with solar charge controller. But this requires more knowledge about electronics.
The easier way is to use a solar LED garden light.
Video: Slug fence with solar power
How far should the distance between the tracks be?
When choosing the distance between the two lines, there are two things to consider.
On the one hand, the two lines should not be too close to each other, because the closer together the quicker a short circuit manifests.
On the other hand, small slugs and snails should be deterred safely. Therefore the strips must be close enough next to each other to do this.
If the strips are too far apart a tiny slugs could move across by only touching one of the strips / wires at a time.
Therefore around 0,4 inch (10 millimeters) distance would be a good choice. Even most young slugs are longer than that.
Maybe you can even lay the tracks a little further apart – as in the video – so it doesn’t shortcut so quickly due to rain or water.
After mounting the tracks / wires, each of the two poles of the battery is connected to one of the wires or strips.
Now the “fence” is under tension and when a slug or snail tries to crawl over, it gets a small electric shock and turns around.
Avoid short circuits
A short circuit occurs if the two lines touch each other or if something (leave, water, slug etc.) completes a connection between them.
In case of a short circuit the battery discharges quickly.
This is why already during construction, it should be ensured that the current-carrying wires are not installed loosely but firmly so that they can not move around.
As mentioned above there should always be a safe distance between them to make sure that they can not touch each other.
Therefore, the self-adhesive copper tape offers some advantage, as once firmly attached it can not move as stretched out wire could.
If the fence is to be mounted on wood, then an easy-to-install perforated metal tape is also suitable.
The perforated tape is a bit more expensive than the copper band. But more stable and durable.
If you know other recommendable models, please leave a comment.
Advantages of electric slug fences
If the fence works, surely no slug or snail will be able to come into the bed. The plants are safe.
That is a huge success compared to many other slug control measures.
The nice thing about this method is that the fence can be built with simple means and do not have to make a big investment.
Another big advantage of the electric fence is, as with other snail fences, that no snail has to die and the plants are still protected.
Disadvantages in the handling
But unfortunately, the fence is safe only as long as electricity flows. If there is an electric problem, the protection is gone immediately.
This is why the electric slug fence must be checked regularly.
Anyone who knows electric fences knows that they can be susceptible to interference. That is also the case with electric slug fences.
A common problem is that a short circuit occurs and the battery discharges and the fence is out of service.
Water conducts electricity therefore short circuits can be caused by rainwater, by watering or irrigation.
Hence the fence should be kept as dry as possible. But this is unfortunately difficult in the garden.
Already the morning dew could help the electric current to find a short cut and the battery will discharge.
Furthermore, short circuits are also caused by slugs and snails which try to pass.
Because if you do not use a 6 volt battery, but a higher voltage, the slugs can die on the fence and then cause the short circuit.
At 6-9 volts they get a shock, but it is not deadly. Therefore, it is important to always stay in the low voltage range and not use higher voltages.
In addition, plants and other animals can cause short circuits.
Thus the power supply of the fence should be checked at least once a day. It is best to check in the evening before the nocturnal animals come out.
If the fence fails, the plants are immediately unprotected.
The electric fence works and it can be a good alternative to other methods of slug control as slug pellets.
The costs are low and the installation is easy. Only if you want to use solar power it becomes a little bit more expensive and complicated.
But the fence needs to be checked regularly, because if there is a problem with the power supply the protection is down immediately.
In order for the fence to work properly, it is good to have a skillful and resourceful craftsman at hand who is ready to repair in case of an emergency.
Its vulnerability to water is impractical in the garden.
Therefore, an electric fence against snail is a good but not the best choice. Because a mechanical slug fence does not have these problems.
The metal slug fence is more fail-safe and durable.
Its initial costs may be a bit higher but on the long run there are no costs of maintenance.
Slug fence electric costs
To build a simple fence you need a copper tape / wire, a battery and an electrical connection to bring the two together.
A good battery costs about 20 dollars / pounds / euros.
The copper band costs about 30 cents per meter. And there might be metal wire that is even cheaper.
But since two lines are needed, the meter prices doubles.
But then the price is still below that of the metallic slug fences, which cost 5 to 7 dollar / pounds / euros per meter.
If you also want to use a solar cell, the costs increase slightly (around 50 dollar / pounds / euros).
Electric slug fence construction manual (DIY update)
This is one possible way to build an electric slug fence, which was send to me by Kay.
He has build this fence and now for years has made good experience with it.
You do not need a complicated circuit for this fence, just a suitable battery cable, a battery and a perforated metal tape.
The perforated tape rusts with the years, but still is long-lasting and especially easy to assemble to wood.
Kay operates the fence with a 12 volt 7 Ah battery. However, a 6 volt battery would be sufficient.
According to him, the battery lasts for a whole season and all slugs and snails are held off successfully.
Also the charger for the battery is cheap.
This fence is particularly suitable for raised beds.
In the open field a bed enclosure is needed to mount the tapes/wires on.
Kay has solved this problem with wooden planks.
Pictures: Kay’s electric slug fence
Effective Slug Control Alternatives
Interesting slug control methods:
slug fences (soon)