what I do is plant one fritillary in each of my flat beds...... this is what the nurseries use to stop the squirrels and other critters from taking their bulbs and it does wanders for the garden pests....
they are called a skunk bulb mostly.
you plant them on their side and they do stink but the come up with a nice flower in the springtime.......
I have done this for years in all my gardens...... never lost a crocus or anything
they also keep cats and dogs from using your flowers beds as a bathroom...........
they are not cheap to buy..........they might bloom the first year and not bloom after that but the bulbs keeps working underground for years and years.......
usually buy them in the fall but you might find them in the spring for sale too.........
you can check out the flower here on the plants site.....just search the name