Water jets are supposed to work but I suggest dried chilli flakes (ethnic aisle in supermarket the cheapest) for deterring mammals, certainly works on rabbits and squirrels and doesn't affect birds
Try sprinkling it where the cat likes to go but use protective gloves youself as it really can sting your mouth or eyes etc.

I can sympathise, I get cat deposits in my garden from neighbouring cats and I haven't found any way to stop them. Sometimes I spread rose prunings or holly cuttings over freshly prepared earth to try to deter them and that helps, but not much stops a determined cat if it wants to use your garden as a toilet:((

I resign myself to having to clear up after them, which isn't pleasant.

If you get a cat of your own it will defend its territory and keep the neighbours cats out.

or getting a big dog?!

I moved house years ago and my two cats strayed into my neighbours garden - unwanted. They used a water pistol on them and once the cats felt the force of the water they never went there again. I suggest you buy a child's water pistol - lay in wait - then shoot. Does not harm the cat but you will not see him/her in your garden again.

This doesn't work for me, I've even used a hosepipe on the cats that come into my garden, they just come when I'm not there:((

It also helps if you don't have the ground in an nice diggable condition as they prefer something easy to scratch up.

In my humble opinion there is NO WAY to stop cats at all.Make sure you always use gardening gloves. It's all fertiliser anyway, and unless they go on the lawn [like my own cat used to!] you can throw a spadeful of earth over it and it will rot down.

Not having clear areas of soil helps as does physical barriers such as lots of bamboo sticks really does work for me. Next door rescues abandoned cats and they now no longer poop in my borders unearthing my bulbs and seedlings.

Don't be too tidy in the borders, pack it with loads of perennial plants so that there is no room for the cats to use it as a toilet. This has worked for me.

Your neighbours can't control there cats, your right but if you see there cat depositing in your garden, ask the neighbour to come over and remove it. Its disgusting when your planting up and your unaware the cats have visited, Since my dog died this has become a problem for me, if i see any cats on my fences i shoo them away and i do what Kildemorie suggested bamboo or sharp sticks pushed into the soil untill i fill my borders up.. YUK.

In the absence of a dog, I have found rose and berberis prunings scattered over any bare areas seem to deter them.

Thank you to all who have replied to my question I have bought some Jeyes fluid and some green gel from Wilkinsons and some Silent Roar lets see if I have any luck with these if not I will try some more of your suggestions

jack russell