Michigan has a long winter, which is why planting bulbs in the fall is an act of faith that we will survive the cold and live for another spring. It is important, though, to know when in autumn to plant those bulbs.
In Michigan, garden centers offer daffodils, tulips, crocus and many other spring-flowering bulbs. Often these will be for sale by Labor Day. Buying bulbs in September is a good idea to get the best selection, but wait until mid-October or even early November to plant them. Bulbs planted earlier than this may produce leaves in the same autumn in which they were planted, and they are also fodder for rodents.
Planting bulbs when the weather is colder deters squirrels and chipmunks who relish certain bulbs, such as tulips. Planting closer to the time the ground freezes makes it difficult for these critters to dig up the bulbs. A general rule is to plant a bulb at a depth that is three times its diameter, but if you have a large population of squirrels, you can plant 1 to 3 inches deeper than this.
Michigan gardeners have other solutions to avoid squirrels and chipmunks. Putting a barrier, such as chicken wire anchored by rocks, over the newly-planted bulbs discourages the furry pests. Other options include using bulb dips that are bitter in taste to rodents, or adding crushed oyster shells that squirrels find unpleasant when they are digging. Finally, plant daffodils rather than tulips because squirrels do not eat them.