Big Ben is a large version of the native false indigo plant. It is a large, upright perennial that produces flower spikes with numerous dark purplish blue pea-like flowers in spring. Pollinators such as birds, bees and butterflies are attracted to these upright spikes that persist for about two weeks. Big Ben grows to about four feet in height and width and has grayish-green foliage. Although removing the flower spikes when they are spent will result in a neater, more rounded plant overall, the seed pods will be lost and these can be a beautiful feature of the winter garden.

Members of the genus Baptisia are commonly known as wild or false indigo due to their use by early Americans as a blue dye. Although "indigo" is in the common name, the blooms of native species may be blue, yellow or white and the blooms of newer hybrids may include lavenders and bi-colors. The late spring or early summer flowers emerge along long stems held above attractive foliage and are followed in the fall by dark pods. Overall habits of the plant are broad-rounded mounds to vase-shaped and range in height from two to five feet. Baptisia are considered easy-to-grow, sun-loving, long-lived perennials with very good drought tolerance once established.

Baptisia are native to North America; there are more than 20 species within the genus. The Chicago Botanic Garden's collection includes over 60 varieties and more than 9,000 individual plants. A number of new varieties of Baptisia have been developed as part of the Plant Breeding program at the Chicago Botanic Garden. Selection criteria included bloom production, color, habit and plant size. These new cultivars have been introduced to the trade through the Chicagoland Grows® program. The Chicago Botanic Garden now holds the national collection of Baptisia under the auspices of the Plant Collections Network of the American Public Gardens Association.