Purple prairie clover is a delicate-looking plant with unique rose-purple to crimson flowers. The densely packed flowers bloom in a ring around the flower head, starting at the bottom and working up to the top. It starts blooming in early summer and continues for a month or more. Older plants may tiller (split) at the base and send up multiple stems, creating vase-shaped clumps.
Purple prairie clover doesn’t look like much in spring (including in the nursery container), but it will reward you in midsummer; a mature plant is quite attractive in full bloom. Plant it in groups of three to five in perennial borders or butterfly gardens, or use a single plant as an accent in rock gardens. The fine-textured foliage remains attractive throughout the growing season, and the seed heads offer winter interest. Plant it with other summer-blooming flowers such as monarda, leadplant, butterfly milkweed, prairie onions and smaller grasses like little bluestem and prairie dropseed. Allow seed heads to remain for winter interest and bird food.
The nectar of the flowers attracts many kinds of bees, including honeybees and bumblebees, which collect pollen. Wasps, flies, small butterflies, hummingbirds, beetles, and plant bugs also visit the flowers. The larvae of dogface sulphur and rieker blue butterflies feed on the plants. Songbirds enjoy the seeds.
Purple prairie clover is slow to develop, but once it settles in, it is a tough, low-maintenance garden plant. Mature plants tolerate summer drought, and clumps seldom need dividing. Be careful not to weed it out in spring. You may need to use an inoculant to help plants become established in some soils. It may self-seed in optimum growing conditions but rarely becomes a pest. Unfortunately, it is a favorite food of herbivores, especially rabbits.
This article by Lynn Steiner originally appeared in the July/August 2019 issue of Northern Gardener. Horticulturist Lynn Steiner is the author of Grow Native: Bringing Natural Beauty to Your Garden (Cool Springs Press, 2016).