My garden is frequently visited by my neighbour’s cats. (I like cats. My sister has 4 cats and my cousins like putting hers in cute fancy dresses!) Last year, one of them started to poo in my garden. I embarked on a battle to stop him from doing so. I have tried many techniques; some based on the principles of sound, smell, novelty and contact and failed most of the time. It was a bit like the movie Catch Me If You Can, except that I was no Leonardo DiCaprio (Frank). I was more like ‘Carl’, the FBI bank fraud agent (Tom Hanks), who kept trying to catch Frank, the Conman, but was always a step behind. Every morning, the first thing I did was to roll up the blind and check if the set up has worked. Sometimes, I was amused by how clever the little cat was! A year on, I am happy to declare that I have won the battle! Here is how I found the ultimate solution against cats fouling in my garden.

My neighbour's cat
General notes:
1. Always remove the cat faeces from the soil. It is not a good fertiliser.
2. Cats like going back to the same spot to make a poo. Clean the area with soapy water helps reducing the smell they are familiar with and makes it less ‘inviting’.

The concept of this is to generate sound that is annoying for cats but not for humans.
I have used battery-powered ultrasonic cat repeller and solar-powered ultrasonic cat repeller. These devices can be used for other pests like foxes and rats, but when I used it I made sure the frequency was set up to target cats. Humans would not be disturbed, in theory. All I needed to do was to place the device at the right place in the garden (and at the right height). The Infra-red sensor is triggered by motion. Sound would then be generated to annoy the cat and this makes my garden a less comfortable toilet.

I was not sure about the concept of the ultrasonic devices before I tried them as I thought they would deter the good cats and bad cats from going to the garden.

1. Battery-powered cat repeller (£21.50, photo from Procter Bros Ltd)

If I forgot to turn it off while I did gardening, I could hear a ‘click’ and see a red light turned on whenever I walked past the sensor. There was a low-frequency (but not annoying) sound. I never could tell if this device had actually worked as I saw the cat wandered pass it many times, without looking disturbed. I did not see much evidence of faeces.

The most annoying impact was, surprisingly, on human. The device had no battery life indicator. Once I was away from home, my neighbour called me to tell me that it was making a lot of high pitch noise. It turned out that it was running out of battery!

2. Solar- powered ultrasonic cat repeller (£29.95, supplied and photo by Primrose)
In response to the battery problem of the first ultrasonic cat repeller. I decided to be environmental friendly and tried a solar-powered one. (photo by Primrose). It said on their website:
‘Your money back if it doesn’t solve your cat problem! We are so convinced that the Solar Cat Repeller will clear your garden of cats, we’ll give you your money back if you’re not 100% satisfied. Simply return it to us any time within 60 days for a full refund of the cost of the product.’

Solar powered sonic cat repeller
I was very excited when I opened the box – it looked all high-tech. At the time, I was also designing a house with photovoltaics on the rooflight. I was happy that I could carry on the ‘theme’ at home. Unfortunately, in the 2 months of me owning the solar-powered cat repeller, the weather was gloomy most of the time. There was just not enough sun to charge the device up. In other words, it did not work most of the time. An adaptor could have been purchased with the device to charge it up when there is no sun. But this was not made clear on the website and I only found out after I read the instructions which came with the box. It did not sound that practical anyway as the device had to be put in the garden but you had to charge the device inside. There would be time when the garden was un-guarded.

I decided to take advantage of the money back return instead. At least the return service was good. I got refunded the postage to return the device as I was mis-informed but I did lose the original £4.95 of delivery charge though.

Cats have a very sensitive sense of smell. In theory, they will stay away from the zone with a smell they do not like. I have tried orange peel, cayenne pepper, cat repellent spray, cat plant and cat repeller pods.

1. Orange peels (£0.15, bought from market)
Cats do not like citric smells. The natural and organic way is to leave orange peels there.

FAILED! The citric smell was quite weak in open air. It can only cover a small area and it disappeared fast. It made no impact at all.

2. Cat repellent spray (£5.99 by Bayer Garden)
It has Aluminium ammonium sulphate, apparently hated by cats, dogs, birds and rabbits. It says on the bottle that it can be used all year around. (photo by Bayer Garden)

It smelled awful. I think I can use it to deter humans too! Unfortunately, my neighbour’s cat did not seem to be bothered by it. He is a young cat so he should be quite sensitive to smell. I was quite disappointed. Perhaps he had a blocked nose or he was being very tolerant.

3. Cayenne pepper (£0.99, local shop)
Apparently cats do not like cayenne pepper because of its heat. Just scattered the power around the area the cat has done its business. (Caution: do not rub your eye after touching cayenne pepper!)

It had no effect on the cat! I used the rest of the cayenne pepper for cooking instead.

4. Cat plant- Coleus canina (£7.95, supplied and photo by Dobies of Devon)
It says on their website: ‘This attractive half-hardy perennial has silver-green foliage and light blue flowers, but it’s the fragrance that’s the secret weapon – indiscernable to humans, it’s highly repellant to cats (but doesn’t harm them). Ideal for pots or borders. Height 60cm (2′)’

For these plants to work, it is best to grow them in pots as they can be moved to ‘target’ areas.

The little plants grew fast which was satisfying from a garden’s point of view. They left an unpleasant smell on your hand when you brushed against them. That was the problem!! The cat would not make a poo right next to the pot. But it did its business a short distance away from it. Hence, for this to work, I really need a lot of them to fill the whole plot up with plants, which means I could not grow any other plants.

And, these plants are not frost resistant- I learnt my lesson as they all died after one cold night!

5. Cat repeller pods (£3.99, supplied by Primose)
Cat repeller pod Apparently, ‘The sharp citrus smell (artificial citronella) is impregnated within the plastic during manufacture, which means no matter what the weather, the Cat Repeller Sticks keep working for up to 10 weeks. Each rod should protect about 1 metre square of area and it conntains no harmful chemicals or pesticides. It is discreet colour and design.’ Sounds ideal, right?

The cats made a poo right next to them. I took that as a sign of protest!

Failing to get any result from the products widely available in the market, I tried to think out of the box. Here is what I have tried:

1. “Don’t sh*t where you eat”
I thought I would try putting food at the cat’s favourite spot to poo. I heard that cats love cleanliness. I thought it would not want to do its business at where it eats. My friends did warn me that the food might attract foxes or other unwanted animals instead.

The cat did not eat any food I left (I wonder if that was because I bought it from Poundland?) Perhaps it already decided that my garden was a toilet, not a canteen.

2. ” Negotiation”
I tried talking to the cat in English and Chinese. He looked at me, blank. (!)

My neighbour's cat
1. Water pistol – super soaker
Out of desperation, we considered shooting the cat with a water pistol.

The cat was super alert. Whenever it sensed any movement, it looked up and ran away. So unless we were there 24/7 or the water pistol was triggered by movement detection sensor, this method does not work. Plus, we might get in trouble with RSPCA!

2. Crushed aluminium foil
I heard that cats do not like walking on crushed aluminium foil. So we gave it a go.

It fouled right next to it. This method only works if I cover the whole area with aluminium foil. This would it impossible for me to grow anything! However, it gave me an idea which ultimately led to the breakthrough!

3. Netting/ chicken wires (supplied and photo by Barnitts Home and Garden)

This was based on the concept that cats did not like walking on chicken wires, which I did not try as I already have plants growing in my garden. I used the netting to create a 3D cage.

It worked! I discovered that it also worked when I covered the soil or planter with net.
If you have a big garden and it was not possible to use net, you can lay the soil with chicken wire before planting. You can cut holes to allow plants to grow through. I have tried this one as I am happy with the netting option. I believe this would work in concept as from experience, I know that cats really do not like walking on this kind of surface!