Indigos are slow-growing, deep-rooted and long-lived members of the bean family (Fabacae).

Cream wild indigo grows close to the ground, while white wild indigo is a shrub-like plant that sends its flower stalk waist high or taller. Both plants are visible from the wildflower trail in early summer.

Members of the bean family are "nitrogen-fixers," meaning they help replace the nitrogen in the soil that plants need to grow.

Chemical fertilizers have taken their place today.

For the prairie gardener, a close relative, blue wild indigo (Baptista australis) is usually available at plant nurseries. It is a bit out of its range in central Illinois, but grows well in gardens here.

Be patient, because it may take a couple of years to mature and flower. It will spend the first year or two sending down its deep taproot.