The best defence against rabbits is to put up physical barriers although I appreciate this isn’t always practical. If you can erect a fence around the affected areas (or your whole garden) this would be the best guarantee of stopping the rabbits. It’s best to use chicken wire and to lay the wire deeply below ground level so the rabbits don’t tunnel underneath. The fence would also need to be 3ft or more tall as rabbits can jump quite high!
If a fence isn’t practical there are a few products available that act as rabbit repellents. You can readily buy granules and sprays which you spread over lawns, flower beds and on the plants themselves to repel wild animals. You can also buy sonic devices which will deter small mammals, although they can be quite pricey.