‘David’ garden phlox is resistant to powdery mildew. Photo courtesy BallHort.com
Phlox was among the first North American native plants discovered and cultivated by European naturalists, dating back to the 1700s.
Like a lot of our native plants, garden phlox (P. paniculata) has enjoyed centuries of popularity in Europe and has been slow to get firmly rooted in American gardens, according to a recent report from Mt. Cuba Center in Hockessin, Delaware.
That is changing. Plant breeders have been working with pollinator-attracting garden phlox to improve the perennial’s disease resistance, flower size and colors. Frequently fragrant, garden phlox is a great cut flowers.
Garden phlox gets powdery mildew, a fungus disease that turns the leaves gray, brown and black. The disease is not usually fatal, but it is unattractive. However, we gardeners live with it, since so many fungicides are deadly to bees. And we try to plant garden phlox that is resistant to this disease. There are several varieties available in late spring and summer at garden centers.
‘Jeana’, found growing along the banks of a Tennessee river, performed the best for its disease resistance, but also because it was highly attractive to butterflies, wrote George Coombs, Mt. Cuba research manager, in the report.
‘David’, a large white-flowering garden phlox, was one of the first to hit the market as a disease-resistant variety. Also highly rated in the Mt. Cuba Center study, it earns good marks from Ann Hathaway, president of the Horticultural Society at Newfields, formerly the Indianapolis Museum of Art.
“I love the brightness of the white, the full bloom, the sturdy stems, length of bloom time and relative disease resistance of the plant. It always looks good,” she said.
Woodland phlox. (C) Photo Chris Evans, bugwood.org
Two other Indiana gardeners – Michael Dana, a horticulture professor at Purdue University, and Rob Chambon in Bicknell – picked the native woodland phlox (P. divaricata) as their favorite. Look for this plant in garden centers in spring.
In the Mt. Cuba study, the species woodland phlox and ‘Blue Moon’ performed the best.
“I like it because it blooms when we’re all looking for confirmation that spring has truly sprung,” Dana said. “And in a woodland or woodland garden setting, it is low maintenance, which always appeals to me, the lazy gardener. The subtle color range of the blues in a wild population is nice too.”
Mildly fragrant, it’s one of our finest shade natives, very low maintenance and drought tolerant, too, said Chambon of Rob’s Secret Garden. “Plus, I really like the way it seeds itself around other areas of the garden without being a bully or thug.”