Shade is both a blessing and a curse. Because gardeners are not immune to the heat of the blazing sun, shade makes any garden more pleasant to be, but it limits the choice of plants that can be successfully grown. Especially lacking are flowering perennials that give good display and thrive in the shade. Fortunately, there’s wild sweet William (Phlox divaricata). This lavender to pinkish-purple (or occasionally white) flowering plant not only grows naturally in the shady areas of a garden, it produces a beautiful display without much fuss or bother for the gardener.

Phlox divaricata
Phlox divaricata is well-suited for gardens throughout the eastern US.
Photo Credit: Dr. Gerald Klingaman
Phlox in woodland garden
Wild sweet William works well in the woodland garden.
Photo Credit: Dr. Gerald Klingaman
Phlox divaricata close up
This shade-loving native wildflower is one of the best.
Photo Credit: Dr. Gerald Klingaman

One of our native woodland phloxes, wild sweet William (also called wild blue phlox) grows best in partial shade, but like most part-shade plants, it’ll grow in sun if it gets some water in summer. It’s also adaptable enough that it’ll grow in heavy shade. The plant is hardy from zones 4-9, ranging from southern Canada to Michigan and as far south as Louisiana and Georgia.

Plants are pubescent, much-branched and grow 10-16 inches tall on slender stems. The growth habit is intermediate between the sprawling form of creeping phlox (P. subulata) and the stiffly erect form of the summer flowering garden phlox (P. paniculata). Tubular flowers bloom from early April through mid-May (but peak bloom is toward the earlier part of the season). They measure 1 inch wide and are produced in a terminal cluster. White and pink forms are occasionally found in the wild. Wild sweet William shrinks away in the heat of summer but reemerges in autumn, with its foliage persisting throughout winter.

Ideal for the woodland garden or shady border, where an early spring display is needed, this pretty perennial is best-suited to areas that offer shade from high oaks and a rich woodland soil containing a high amount of organic matter. Good wintertime drainage is essential. The plant tolerates periods of drought but performs best if given some water during dry spells. In the right spot, it’ll reseed and increase the size of the colony, but usually garden plants are rooted from cuttings taken in summer. Older clumps may be divided in the fall, or seedlings lifted and relocated around the garden. Its open and natural form makes wild sweet William ideal for use as a single specimen or in large drifts of color to brighten the dark recesses of the shady spring garden.

The 60 species of phloxes native to North America were quickly recognized as valuable garden plants by early European plant explorers. Wild sweet William never hit the big-time status of the summer-flowering garden phlox, but its popularity as a garden plant in Europe has always been higher than here in the US.

Give this garden gem a try in your shady spot and let it shine!