The best defense against rabbits is a 3-foot-tall chicken-wire fence (1-inch mesh or smaller) with another 6 inches buried in the soil. Or you can try odor repellents such as blood meal or powdered fox urine (available at your local garden center). These usually need to be reapplied frequently. Spray-on taste repellents such as hot pepper spray are also available. It must be put directly on the plants, so rabbits get a good taste of it when they settle in for their snack. It also needs to be reapplied periodically.
You can also place a row cover over your beds while the plants are small, removing it once new growth is well under way. Because rabbits prefer tender, young growth, try keeping your flowers covered for a few weeks in spring, then switching to an odor or taste repellent when the covers are removed. The rabbits may lose interest in your garden.