Absolutely nothing. If you don't want to use slug/snail poison, get some copper tape to put around the base of the bushes. Then there are beer traps. Since I have cats and don't like to have poison out, I tried cutting holes in a plastic container (Dream Whip) and putting a shallow container inside with the pellets. Kind of like a slug motel. It worked for a while. Good luck, it's a universal problem.

I can recommend beer traps - first time I used one I caught 30 slugs in one night!! All you do is bury up to the rim a cup and fill it with cheap beer. Slugs are attracted and they drown in the beer. This is the safest way for wildlife - slug pellets are being blamed for the falling number of hedgehogs.