Posted: 17/05/2013 at 14:07
Do not waste your time on fluids, 'anti cat plants' and other crap people keep spewing.
There are 2 ways to stop cats digging (which is hiding their poo):
1. Have plants! Ie do not have areas of bare ground/earth.
2. If you do have areas of bare ground (waiting for bulbs/perennials etc) then put lots of bamboo sticks around to physically stop them getting there. Remove sticks as the plants grow.
Easy and cost free.