Four triangular gardening plots form a square as shown. Each plot will contain one kind of flower, and flowers in plots that share an edge will be different. How many different ways can the garden be planted if the flowers can be roses, carnations, daisies, lilies, or tulips?

This is the best picture I could find except it's "square" shaped rather than a "diamond"...-http://www.rogersconnection.com/images/p32.gif

Any help is great. Thanks :)