[madcat]

Holly prunings work well on newly turned earth, as does black pepper (but that has to be renewed after rain). Laughing helps too - cats hate to be laughed at at any time (there speaks a person owned by cats), so laughing at them when pooping is very effective!

Once you stop the cycle, it doesn't tend to restart, because the 'messaging' with it goes elsewhere.

[strangerachael]

or you could try setting up an even more tempting toilet just away from your veg plot - maybe a plastic sand tray (with holes in the base for drainage) filled with freshly dug soil and sand . You would have to keep removing the poos but at least if it worked you would have poo-free veg beds.

[Goosegirl]

Good idea - forgot to think of that one. If you can transfer some soil from their toilet area to another freshly-dug area, that should help.

[Bohobumble]

You can see my garlic versus cat battles here: https://greengardengate.wordpress.com/2014/03/18/garlic/

Last year I did all the poo duties, this year OH has his turn as I am far too busy with my allotment to garden at home too.