A motion activated sprinkler system is the best for keeping cats away, available on Amazon and other places.

Slugs and snails, there's a range of treatments available, I personally favour Eraza rain proof slug pellets as the most effective and least frequent need for application, but they contain metaldehyde so if you don't like to use chemicals, then you're confined to the more organic solutions like nematodes, non chemical pellets, etc. There is no final solution, you have to constantly reapply whatever product you decide on, and some more frequently than others. Google Nemesys for information on nematode solutions.

In my experience, a few plants of Garden Rue (Ruta graveolens) will repel most cats.

Green Gardener sells slug nematodes. Expensive but effective.

I don't regard cats as garden pests, so can't help you with that.

Many thanks to Bamboo, Tugbrethil and Rosierose for your very helpful suggestions.
We will try them and report back.
Greatly appreciated !

Kind regards,
Louis and Eli du Toit

Beer traps for slugs and nothing will work for cats. You may not see them in the day but they're all over the place at night when your are sleeping.

Well, they're not too keen on a soaking every time they enter the garden, Loosestrife, though I'm guessing this solution might not be appropriate in large gardens;-)

With reference to the plant Rue, or Ruta graveolens - its not readily available at many outlets any more but can be found at specialist herb suppliers and online suppliers, occasionally as large plants at garden centres. The reason for this is it can cause a painful blistering of the skin in some people (specially children) if they brush against it, in particular when they (and the plant) are in the sun. Ruta graveolens 'Jackman's Blue' is a very attractive plant though... I can't say it bothered any of my cats, but then I didn't have it more than 4 months after one incident of blistered legs with my (very young at the time) son.

Ah! Neverhad that experience--or heard of it--Bamboo. Possibly I've just been lucky.

It didn't affect me either, Tug - I found out about it the hard way, or rather my son did. I've never planted it since in client's gardens for that reason. Shame, because it has a great colour and leaf shape...

I've been using diatomaceous earth around my vegetable plants - cabbage, beets, bell peppers. Not a nibble to be seen. I've just posted a couple pics today in the main gallery if you want to take a look.

I had an invading cat for a while which was marking its territory in a gravel path and newly dug raised bed. I was told to use household white pepper which I sprinkled over the paths and soil. I haven't seen cat poo since and it's rained since.

That's a great idea Barbara! I am going to try that as we have a cat which sneaks up here after my birds. Shouting, chasing and bucket of water (I missed) haven't worked so far, so am willing to try anything.

Just don't use chili powder, ordinary pepper's bad enough for a cat, given they lick their paws. Although chili works too, the RSPCA has requested that gardeners do not use it - too many animals being brought in needing emergency treatment as a result.

Just curious, but treatment for what, Bamboo? In my ignorance, I thought that the effect of chili peppers was a temporary pain.

Blisters and sores on their tongue and eye irritations. This is a cruel method of repelling animals. Why would anyone knowingly cause an innocent animal like a cat or dog even a temporary pain?

As Loosestrife describes, Tug...along with pain and significant stress/distress, of course. Even Gardener's Question Time on BBC Radio 4 put out the message from the RSPCA, gardeners being the ones using chili pepper to keep off squirrels, cats and any creature interfering with their plants.

After I asked, I thought of the possibility that they might injure themselves trying to get rid of the pain. I certainly wouldn't want my kitties feeling that way!!

Some years ago I put down some chilli pepper in desperation trying to repel a badger but when I accidentally got a tiny bit in my own eye I never used it again. I had used it before to deter field voles which had ring barked a cotoneaster and killed it - nothing else had worked. But I feel very sorry I did it now.

My pepper plants do a pretty good job at repelling neighborhood cats as well.