The theory behind this method is that all slugs and snails move on a slime layer.
Since hair or sheep’s wool would absorb the mucus fast, the snails are prevented from moving over it.
At least that’s what you can read about this slug control measure.
Sheep’s wool pellets against snails
The commercial product to test would be sheep’s wool pellets.
They are made of wool rests, which are unsuitable for other uses.
So no sheep needs to be killed for that. It is sort of a waste that is pressed into the small wool pellets.
In addition, the pellets contain salt and sand, which additionally should deter the slugs.
Hair and sheep’s wool in the test
Since there are different opinions about the effectiveness of this method, I have made some tests to check the effect that hair and wool have on slugs and snails.
In a first test I used human hair. In a second round I tried fresh sheep wool and in a third test I used the same wool after a heavy rainfall.
The results I recorded in videos.
First, the test with the normal washed human hair.
As in similar experiments, I formed a semicircle with the hair and put freshly collected snails in the middle of it.
After that I closely watched and filmed what happened.
Video 1: Human hair against snails in the test
As you can easily see, the snails are unaffected by the hair.
They crawl over it and hide under it. So human hair has clearly failed to deter slugs.
Therefore, I made a second attempt with fresh greasy and dirty sheep wool, which has been kindly offered to me by a befriended farmer.
There were remnants of sheep droppings in the wool and the wool exuded the strong smell of sheep.
The experimental setup was similar to the hair experiment.
However, this time I changed the setting a little bit. I used bricks so that the slugs could not crawl under and hide beneath the wool, as they did with the hair.
In addition, this was a protection for the wool to not be blown away by the wind.
Video 2: Sheep’s wool against snails in the test
Here is an amazing result. The snails do not go over the wool.
They try, but after a few attempts, all slugs and snails turn around.
Thus the wool worked much better than expected after the fail with the hair.
The slugs tried to crawl over the wool, but after their sensitive feelers / tentacles came in touch with the fine wool hairs, they backed away.
They did not like the wool at all.
Therefore, I hoped that the wool would also work after it has become wet and was washed by rain.
Video 3: Sheep’s wool under test – after heavy rain
Unfortunately, the wool could not really convince after the rain.
The defensive effect was not completely gone, but it was much less than before.
It could still deter some of the snails but most slugs passed it without hesitation.
Maybe because the salt or other repelling substances were washed out.
Therefore, the method could be useful if the wool is used in areas protected from rain and irrigation water.
So for example in a greenhouse, in a tomato house, in a winter garden or in all sorts of covered terrain.
And if you are or know a shepherd or a shepherdess, you could get plenty of dirty wool each springtime.
Otherwise, there are the already mentioned sheep wool pellets.
But it is doubtful that the pellets would be resistant to rain.
Finally, the advantage remains that sheep’s wool and wool pellets serve also as a good long-term biological fertilizer that contributes to soil health.
How are the pellets used?
The pellets swell up when they come into contact with moisture and are likely to lose their deterring effect after heavy rainfalls.
But if they are spread thick and wide around endangered plants or beds, they form a barrier that is difficult for the snails to overcome.
A protection ring made of sheep wool pellets should be at least 4 inches (10 cm) wide and also a few inches (centimeters) thick. Otherwise bridges could quickly form and the protective effect would be gone.
Since I only tested the fresh sheep wool, I would be happy about comments regarding your experience with pellets.
I plan to conduct some tests in the future.
Can slugs be deterred by sheep wool mulch mats?
A second method works with sheep wool mats or sheep wool felt, which is placed on the beds.
The mats could be cut into wide strips. Then the strips are placed around beds and could serve as a kind of slug fence.
The assumption is that wool is only supposed to repel slugs if it has not been washed yet.
However, since most mats are washed, it is unsure if they are just as effective as fresh wool.
I have been told that the mats dissolve in the rain over time and thus are not an effective obstacle for slugs.
But since opinions differ, I would be happy to receive further hints and comments.
Benefits of sheep wool as a means of fighting snails
The application of wool as pellets is very easy and fast.
In comparison with other materials such as ashes or coffee grounds it stands out positive that the wool should remain effective after rain – at least for a while.
A nice side effect of this method is that the wool serves as a longterm slow-release fertilizer.
Similar to bone meal, the wool decomposes only very slowly and releases nitrogen into the ground over a long period of time.
In addition, it contributes to the soil’s looseness and its capacity to hold water.
Wool and pellets also contain sheep droppings, which are directly available to the plants as fertilizer.
Furthermore the wool in the beds serves as a protection against dehydration, since the pellets and the mats become a kind of mulch.
But since mulch and moisture are usually a magnet for slugs and snails, the mulching material should be picked with great care during acute snail pests.
Therefore, sheep’s wool may provide a good alternative mulching material, which at the same time protects the plants against slugs at least for a while.
Unfortunately there are very different opinions on the effectiveness of sheep´s wool and pellets against snails.
As a result, the sheep´s wool pellets have failed in some tests, and in others they have worked well.
Probably it depends on the application or on the actual products in use.
The same considerations apply to the usage of sheep wool mats.
Again there is the one group for which the mats work and then the other, where they turned out to be a flop.
It appears to play an important role, that the wool should neither be cleaned nor degreased.
The “fresh” raw wool still stinks strongly of sheep. It is salty and filthy, but this is probably why it successfully keeps away all slugs and snails.
For example in the gardens of the University of Tübingen the gardeners work successfully with wool and wool stripes placed around the vegetable beds.
Products and prices
The price of sheep’s wool pellets fluctuates relatively high.
One famous product is called “slug gone”.
However, there are also differences in the composition of the pellets.
Because not all products were specifically produced as snail protection.
Most are intended primarily as slow-release fertilizer for organic farming or gardening.
The sheep’s wool mats were also designed primarily as ground cover and not as a snail defense.
Therefore, my suggestion is: Try it out and study its effects.
Good luck and fortune in the garden!
Effective Slug Control Alternatives
Some interesting slug control methods:
slug fences (soon)