Biodiversity & Pollinators

Andrew Bunting

In recent years, a greater understanding of the importance of biodiversity has emerged. The term biodiversity refers to the network of all global species, including plants, animals, birds, insects, fungi and more. Humans rely on biodiversity for many resources, including food, water and medicine. It also plays an important role in managing the Earth’s climate. Carbon dioxide is absorbed by plants, which helps to moderate climate change.

A biodiverse planet is key for most types of pollination in the plant world. For example, if there isn’t a biodiversity of plants and insects, and birds to pollinate them, then seed and fruit production would be greatly impacted.

Garden centers, growers and homeowners can play a role in supporting biodiversity by growing and planting myriad pollinator plants that attract dozens of native pollinators.

One such pollinator plant is the garden phlox Phlox paniculata Jeana. This is a tremendous garden phlox that flowers in the summer and blooms for several months. It’s covered with an abundance of flower heads with small, fragrant, pink flowers, which are a magnet to butterflies and the ruby-throated hummingbird. Jeana also has great resistance to powdery mildew, which ravages most cultivars of garden phlox.

A great native of the Midwestern prairies is the rattlesnake master Eryngium yuccifolium. Blooming from June to September, this very drought-tolerant perennial will reach up to 5 ft. tall. At the base, it sets a rosette of serrated leaves and then towering above the foliage are wiry stems with a spray of white thimble-like flowers. This stalwart native has an architectural quality. The rattlesnake master attracts an abundance of pollinating bees, wasps and flies.

Of course, one of the best and most attractive of all the perennials to attract pollinators is the host of coneflowers (echinacea). Over the last 20 years, coneflowers have had an amazing renaissance in American gardens. Over this period, hundreds of species, hybrids and cultivars have been selected and promoted for their beauty and ability to attract a variety of pollinators, including long-tongued bees and butterflies such as fritillaries, monarchs, painted ladies and swallowtails.

The purple coneflower (Echinacea purpurea) now comes in many colors, including orange, yellow, pink, white and even red. Other exceptional cultivars from plant evaluations conducted at the Mt. Cuba Center in Delaware include Pica Bella, Sensation Pink, Santa Fe, Snow Cone, Glowing Dream, Fragrant Angel and Julia.

Other great species include the Tennessee coneflower (Echinacea tennesseensis) with rose-pink flowers or the pale pink coneflower (Echinacea pallida) with long drooping petals and shuttlecock-like flowers, as well as Echinacea paradoxa, with black-eyed-Susan-like yellow flowers and a black center. When finished flowering, coneflowers also become a great food and seed source for the American Goldfinch.

Other exceptional pollinators include the bee balm cultivar, of which there are many great cultivars and species available at garden centers. Jacob Cline has tubular clusters of fire-engine red flowers. All bee balms are deer resistant because of their fragrant foliage, and Jacob Cline is a cultivar that’s stood the test of time because it’s also powdery mildew resistant. Reaching 4  to 5 ft. tall, it’ll also quickly spread into a large mass in the garden. With soft lilac flowers, Monarda bradburiana is another favorite that only reaches 2 ft. tall in the garden and is earlier flowering.

There are also dozens of native species of milkweeds throughout the United States. The butterfly milkweed (Asclepias tuberosa) has grown in popularity as an important host for the Monarch Butterfly. Reaching about 12 in. tall, this tough native milkweed is covered in bright orange, upward-facing flowers from mid-June into the summer. I have it growing in my gravel garden where it’s proven to be extremely drought tolerant, as well as resistant to deer.

The butterfly milkweed can be difficult to establish, but is worth the effort. Once it’s established in the garden, it’ll spread and seed around serendipitously in the garden, “popping up here and there.” The swamp milkweed (Asclepias incarnata) reaches 3 ft. tall with soft pink flowers. Ice Ballet has white flowers. As the common name would imply, it can tolerate poor drained or even swampy soils.

Without a doubt, one of the best-of-the best for the pollinator garden are the mountain mints (pycnanthemum). Pycnanthemum muticum grows in sun or shade, but thrives best in full sun. It quickly turns into large colonies in the garden by expanding by underground stems. Reaching 3 ft. tall, it’s a great perennial for the front of the border. The foliage and flower bracts are smokey-white, and the flowers have small globular heads with very tiny flowers that are highly attractive to many pollinators. The leaves have a minty fragrance when crushed and pycnanthemum is truly deer resistant. Also, great pollinator plants are the Virginia mountain mint (P. virginianum) and fine foliaged species like Pycnanthemum tenuifolium.

With so many excellent varieties and cultivars of pollinator plants widely available in garden centers and nurseries today, supporting biodiversity in your garden has never been simpler. The varieties mentioned above are just a snapshot of pollinator plant species that are well suited to different garden conditions, and many offer the added benefits of being deer or disease resistant. Whatever your garden’s aesthetic goals, pollinator plants can add beauty and interest, while also supporting vital wildlife. GP

Andrew Bunting is the Vice President of Horticulture for the Pennsylvania Horticultural Society, which uses horticulture to advance the health and well-being of the Greater Philadelphia region. To learn more about PHS, or to become a member and support greening initiatives in over 250 neighborhoods, visit PHSonline.org.