Even with the increased heat and humidity there are many perennials and shrubs in full flower this time of year that are great for attracting pollinators.
Though some of the earliest hydrangeas are finishing flowering, there are many more that are in peak flower now. The native smooth hydrangea, Hydrangea arborescens, is in full flower. This hydrangea is found throughout the woods in the Eastern U.S.
While many hydrangeas are characterized by a head of showy florets or bracts, the smooth hydrangea is noteworthy for its mass of fertile flowers in the center surrounded by some outer showy bracts. This species is not as ornamental as those types with the big round heads of flowers, but it redeems itself by having amazing ecological capacity. All those fertile flowers are an amazing magnet for a host of pollinators.
“Haas’ Halo” is a selection with large, flat-topped clusters of fertile flowers. The Mt. Cuba Center in Delaware ranked “Haas’ Halo” as one of the best performers for attracting pollinators. “Annabelle” is a selection of the smooth hydrangea with large, white mopheads, but offers little fertile flowers for the pollinators. All the Hydrangea arborescens types can thrive in both shade and sun.
Another great pollinator plant in the garden coming into flower are the mountain mints. In particular, Pycnanthemum muticum is considered one of the best-of-the-best for attracting a myriad of pollinating moths, wasps, butterflies and bees.
This mint relative is upright, growing to 2.5 feet tall. The leaves have a mint-like fragrance, which has proven to be deer resistant. While it will spread over time, it by no means is as rambunctious in its growth habit as spearmint or peppermint. The leaves have an ornamental dusty white cast to the foliage and the pink flowers, nearly microscopic to the eye, attract an amazing array of pollinators.
Many of the native eryngiums make great pollinator plants like the rattlesnake master, Eryngium yuccifolium, and the Texas annual native with iridescent purple flowers, Eryngium leavenworthii. Also worth considering is a low-growing hybrid at the Scott Arboretum of Swarthmore College, Eryngium x zabelii “Big Blue.” Commonly called the sea holly for its sea blue coloring and its spiny holly-like leaves, this hybrid between E. alpinum and E. bourgatii, has amazing spiny, blue flowers that reach about 30 inches tall. All the eryngiums like good drainage and would be perfect in a gravel garden.
The garden phlox, Phlox paniculata, has a vast native distribution throughout the U.S. Dozens of cultivars have been selected. Many of the cultivars are highly susceptible to powdery mildew, which can cover the leaves and discolor them in the summer. “Blue Paradise” has fairly good resistance and has pinkish-blue flowers that occur in upright clusters.
Garden phlox will reach 3 feet to 6 feet tall at maturity and it flowers best in full sun.
Unequaled for its “flower power” and ability to attract pollinators is “Jeana.” It has bubblegum pink flowers which are smaller than most cultivars, however, they occur in profusion and the plants are taller than most. In 2024, “Jeana” received the “Perennial Plant of the Year” by the Perennial Plant Association.
Just a walk around the Scott Arboretum or your local streets will reveal many other great pollinator plants in flower now such as rudbeckia, lavender, coneflowers, and the bee balms, Monarda, which are coveted by the native ruby-throated hummingbird.
Andrew Bunting is vice president of horticulture at the Pennsylvania Horticultural Society and vice president of the Swarthmore Horticultural Society.
Join our readers whose generous donations are making it possible for you to read our news coverage. Help keep local journalism alive and our community strong. Donate today.
