Blue Phlox (Wild Sweet William)

Photo of blue phlox (wild sweet William) plant with flowers
Scientific Name
Phlox divaricata
Polemoniaceae (phloxes)

A perennial herb with lance-shaped, evergreen leaves and showy, rounded clusters of (usually) lavender flowers. Flowers tubular with 5 lobes, the lobes spreading, somewhat heart-shaped, with or without fine notches, in varying colors: pale blue-purple, red-purple, rose-lavender, rarely white. Blooms April–June. Leaves opposite, lance-shaped, spaced apart, to 2 inches long, finely hairy. Dark green, leafy shoots spread from base, take root, and persist through the winter.

Other Common Names
Woodland Phlox

Height: to 1 foot.

Where To Find
image of Blue Phlox Wild Sweet William Distribution Map

Statewide, except for the southeast lowlands.

Occurs in rich or rocky soils in open woods, thickets, wet streamsides, bottomlands, usually in partial or full shade, but sometimes in full sun. A native to much of the eastern United States, blue phlox is also found in cultivation, and some forms have been created just for gardening.

Blue phlox does well in wildflower gardens, thriving in shade or part-shade, in rich soils. Be sure you get your plants from an ethical native-plant nursery; don't dig them from the wild.

Missouri's lovely spring wildflowers help create the scenic beauty that is a big part of our state's tourism. Wildflowers also contribute to our sense of well-being after a long winter.

Butterflies are attracted to this species of phlox, and in fact, only insects with long tongues can reach far enough down the flower tube to reach the nectar. Thus butterflies and skippers, moths (especially various sphinx moths), and long-tongued bees (such as bumble bees) are the principal pollinators. Blue phlox flowers must be cross-pollinated in order to produce viable seed, so this plant requires the help of insect pollinators to reproduce.

Several animals eat the plant, as well. These include rabbits and deer, which browse the foliage, but also insects. The caterpillars of the darker-spotted straw moth (Heliothis phloxiphaga) feed on the flowers and seeds of phlox plants. The caterpillars of a moth called the "olive arches" (Lacinipolia olivacea) are known to chew phlox leaves (plus the leaves of several other plants, too). The phlox plant bug (Lopidea davisi) sucks juices from the flowers and flower buds.

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Similar Species

Where to See Species

Rockwoods Range is a premium stop for outdoor adventurers. The area is mostly forested, but you'll also encounter glades and other natural habitats.
The Thompson Ford Fishing Access, located on the Little St. Francis River, is an 84-acre tract of woodland and old fields.
About Wildflowers, Grasses and Other Nonwoody Plants in Missouri
A very simple way of thinking about the green world is to divide the vascular plants into two groups: woody and nonwoody (or herbaceous). But this is an artificial division; many plant families include some species that are woody and some that are not. The diversity of nonwoody vascular plants is staggering! Think of all the ferns, grasses, sedges, lilies, peas, sunflowers, nightshades, milkweeds, mustards, mints, and mallows — weeds and wildflowers — and many more!