Chillies work to some extent. I've tried chilli powder which washes or blows away over time. Someone else on here, I forget who (sorry) used chopped chillies from the "ethnic" aisle of their local supermarket and they seemed to work, but I don't know how long they'd stay effective for.

I was losing lots of bulbs and seeds to mice this spring. In the end I got the mouse traps out, caught 6, then no more. Sometimes you just have to reduce the numbers.

It would probably be helpful if you could work out what your enemies are. You can fence against rabbits - no help against mice and rats though.