Late-season Pollinator Plants
Late summer is a crucial time for providing nectar and pollen for pollinators. Ruby-throated hummingbirds (Archilochus colubris) and monarch butterflies (Danaus plexippus) migrate to warmer climates, while bumblebees and other insect pollinators may overwinter with us. Each species needs to store body fat to provide the energy necessary to perform the long-distance flight and survive the journey.
Late summer and fall blooms provide food when other native plants have finished their blooming cycle. Adding a few late-blooming plants to your garden helps pollinators survive winter, with the reward of having these beautiful creatures in your garden. Perhaps overwintering insects and returning hummingbirds will survive to enjoy your gardens next year.
Several excellent species that attract pollinators might not be on your list for consideration because they create visions of abandoned fields and roadside "weeds." Even so, their colors and showiness can be an attractive addition to any native plant or pollinator garden.
Joe Pye (Eutrochium dubium) is an excellent late-season source of nectar and a magnificent late bloomer in the pollinator garden. Joe Pye has beautiful dome-like pink flowers that bloom from mid-summer to early fall.
Joe Pye attracts monarch butterflies, several species of swallowtail butterflies and many native bees. Joe Pye grows well in full sun to part shade and prefers moist soil. This plant can grow to a height of 5 feet and does well when planted at the edge of a woodland garden.
Common boneset (Eupatorium perfoliatum) is a close relative to Joe Pye, with a bloom time spanning June through October. Boneset can grow in full sun to shade with a preference for moist soil. It is also a tall plant, growing 3 to 6 feet, with tiny white flowers that grow in flat clusters.
Boneset attracts butterflies, bumblebees, and beneficial predatory wasps to the garden. It is also the host plant for the three-lined flower moth (Schinia trifascia) and the boneset borer moth (Carmenta bassiformis). The seeds of boneset attract many seed-eating birds and provide a food source throughout the winter season if garden cleanup is left until spring.
Goldenrods (Solidago spp.) are members of the aster family and are known for their bright yellow flower clusters, generally blooming from July through October.
Deer and rabbit-resistant goldenrods also have few insect or disease problems. Some species can spread aggressively; however, several species behave well in a garden. These include blue-stemmed (S. caesia); zigzag (S. flexicaulis); anise-scented (S. odora) and showy (S. speciosa) goldenrods as well as a cultivar of rough goldenrod (S. rugosa “Fireworks”).
Blue-stemmed goldenrod works very well in a shady area and grows only 1 to 3 feet in height. Like blue-stemmed goldenrod, zigzag goldenrod is also shade tolerant and an excellent choice for a woodland setting though it will reach 2 to 4 feet. Anise-scented goldenrod prefers sun and moist soils and grows 3 to 6 feet. The leaves emit a licorice scent when bruised. Showy goldenrod grows to 4 feet and forms clumps. Lastly, “Fireworks” goldenrod is noteworthy for its long arching sprays of flowers that resemble a fireworks starburst. It prefers well-drained soil and full sun.
New York ironweed (Vernonia noveboracensis) is covered with bright purple flower clusters mid-summer to mid-fall. It grows well in full sun to part shade in almost any soil reaching 5 to 8 feet in height. It performs best in moist and wet areas but will survive prolonged periods of drought.
Any of these late-blooming native perennials would be an asset to a pollinator garden. Try to find space for one or several. If the height is an issue, prune them in late spring. Deadheading after blooming will prevent seeds from dispersing but think about keeping at least some seed heads as food for wintering birds.
To learn more about native fall perennials, visit Penn State Extension (https://extension.psu.edu/native-perennials-for-fall). If you have questions about native perennials or fall gardening, call the Butler County Master Gardener Garden Hotline at 724-287 4761, ext. 7, or email the Master Gardeners at butlermg@psu.edu.
Mary Alice Koeneke and Diane Walczak are Penn State Extension Master Gardeners of Butler County.
