The only reliable way I've found for borders is some old metal 1ft x 1ft linked fencing sections that the previous owner left behind. A bit ugly, but does the job until the plants are established

Failing that fill the beds so full that the cats can't get in there.

One of our cat's has recently taken to jumping in the middle of a Hebe that is 2ft across - I can't see that it's comfortable for him though....

I cut back long lengths of bramble every autumn and roll them up like i would a hose pipe. I leave them die and dry, then uncurl them and lay them round the borders. No Sweetums likes pricklies on their paws, nor scratched bums.

Plastic mesh, hole size about 3cm has been a perfect solution for me. Other hole sizes may work also. Dark green most recommended colour, or possibly brown for soil.

thanks for all the ideas...... i have been reading about coleus canina. what are your opinions on weather it works or not?

I tried coleus canina for this purpose once- very interesting flowers, but be warned the smell can repel a grown man too.

I have had the same problem the last few days, picking cat muck from the same place in my front border YUK.
So I sprinkled KEEP OFF around the area and pushed spiked sticks into the soil and its worked, fingers crossed, once the plants are up in that area ill breathe a sigh of relief as its usually bare soil thats attractive to cats..
PS, this method doesen't distract the birds from scratching at the soil LOL..

I use plasticised wire fence mesh (similar idea to Jonathan's plastic, but a larger gauge) or even chicken wire, laid out at soil level and cut to accommodate the plants until they fill out enough to leave no gaps...and spikes cut from canes.

spread cloves around your border they hate the smell,
whole cloves from the supemarket only 60pence.....

Thankyou for all the ideas. i think i will try he mesh and spikey sticks to start with and just pack the border witth plants. Young d where do you get KEEP OFF from