This purple, fall-blooming crocus is the source of the spice saffron, which is actually the red stigmas of the saffron flower. Although it is very expensive to buy saffron, the plant is easy to grow and provides a nice source of color in the fall when not much else is in bloom. Saffron likes a dry summer, so it is important not to overwater it when dormant to prevent the corms from rotting.