Alternative to pebbles - cat keeps pooing on them :-(

[hillbilly]

We live in Central London and have a garden about 8 x 5 metres. Currently it is mostly paved with an area of astroturf and a pebbled area near the gate. The problem we have is that our cat uses the pebbled area as a toilet EVERY winter. As soon as it gets warm again she stops (and obviously goes further afield). Anyway we are sick of it and want to find an alternative to pebbles. I don't want to put more paving down partly because of the drainage aspect and also because it will be hard to match what we already have which has been there for 7 years.

Any suggestions would be gratefully received!

[Rhubarbgarden]

Soil and plants?

[ComeIntoTheGardenMaud]

If you are after low maintenance, soil and plants may be better than pooed-on pebbles!