Understanding the Dietary Needs of Pollinators: Insights from University Research

Common pollinators like bees and butterflies have seen their numbers threatened in recent years. Various factors cause this, but any gardeners or landscape architects interested in supporting them can start by understanding their dietary needs.

In this blog, we’ll explore the specific dietary needs of pollinators. We’ll also give you some suggestions as to which plants you can plant to support these species best.

The Dietary Needs of Bees

As a species that gathers pollen on purpose, bees are extremely important pollinators in many agricultural systems, including the Northeastern U.S. Bees feed entirely on flowers from the larval stage through adulthood. 

Nectar is a primary source of carbohydrates for bees, so plants that produce abundant nectar are particularly attractive to them. They also consume pollen as a source of protein and lipids, which is particularly important for developing bee larvae.

What To Plant to Support Bees’ Dietary Needs

While some bee species feed only on certain flowers, many bee species (including bumble bees) are generalists who visit a wide variety. A major challenge for native bees is the summer dearth, a period in mid to late summer when many landscapes have few native species blooming. By providing plants that bloom in this window, you can support and enhance populations of bees. Those interested in cultivating a landscape specifically to support bees should consider plants like:

Blue Vervain (Verbena hastata)

Blue Vervain is a perennial plant with slender spikes of blue-violet flowers that supply bees with nectar and pollen during the mid to late summer.

Partridge Pea (Chamaecrista fasciculata)

Partridge Pea is a yellow flowered annual species that blooms in late summer and early fall. It produces nectar in extrafloral nectaries on its stems.

Oxeye Sunflower (Heliopsis helianthoides)

Oxeye Sunflower is a yellow flowered perennial species that bloom in late summer and early fall. 

Wild Senna (Senna hebecarpa) 

Wild Senna is a long-lived perennial that blooms in late summer with yellow flowers. Its pollen is accessible only through buzz pollination by bumble bees. The protein to lipid ratio of this pollen is ideal for bumble bees to raise their brood.

Wild Bergamot (Monarda fistulosa)

Wild Bergamot is also known as bee balm. It is a fragrant perennial with lavender flowers that attracts bees by offering abundant nectar in mid to late summer.

Bees will naturally locate and feed from an appropriate mix of plants, providing them with their preferred balance of essential nutrients. Those interested in helping support bees should plant a diverse garden with flowers blooming at different times of the year. This will ensure your local bee population has another continuous food supply throughout the year.

Hummingbirds and Their Dietary Needs

As specialized nectar feeders, hummingbirds play a crucial role as pollinators. From fledgling to adulthood, hummingbirds rely heavily on flowers for their nutritional needs.

Nectar is the primary source of carbohydrates for hummingbirds, fueling their incredibly high metabolism and energetic flight patterns. In addition to nectar, they consume small insects and spiders to obtain essential proteins and other nutrients.

Insects in the Hummingbird Diet

While nectar is a critical carbohydrate source for hummingbirds, insects supply the protein and nutrients necessary for muscle development, feather growth, and overall health. 

Hummingbirds eat various small insects and arthropods, including gnats, fruit flies, aphids, mosquitoes, and tiny spiders. Incorporating leaf litter, water sources, and dense foliage can create a welcoming habitat for insects and provide a natural food supply for hummingbirds.

What To Plant to Support Hummingbirds’ Dietary Needs

A garden rich in nectar-producing flowers and conducive to insect life will provide hummingbirds with the energy and protein sources they need. Consider plants like:

Eastern Columbine (Aquilegia canadensis)

Eastern Columbine features red and yellow, nectar-rich, tubular flowers that bloom in early spring. These flowers provide an essential food source for hummingbirds when other resources are scarce.

Black Locust (Robinia pseudoacacia)

Black Locust is a deciduous tree that produces clusters of fragrant white flowers in late spring. Its blossoms offer abundant nectar, attracting hummingbirds and other pollinators.

Tall White Beardtongue (Penstemon digitalis)

Tall White Beardtongue is a perennial with white flowers that bloom in late spring to early summer. During this crucial period, the flowers supply hummingbirds with nectar.

Swamp Milkweed (Asclepias incarnata)

Swamp Milkweed is a hardy perennial that blooms with clusters of pink flowers in mid to late summer. While well-known for attracting butterflies, its nectar-rich flowers are also a valuable food source for hummingbirds.

Planting native species that bloom at different times ensures a continuous food supply to meet hummingbirds’ high-energy demands throughout the season. Supporting hummingbirds in this way helps these vibrant birds thrive and enhances the ecological health of your garden.

Understanding the Dietary Needs of Pollinator Butterflies

Butterflies are a delight to observe and play a significant role in pollination. Their attraction to colorful flowers like Butterfly Milkweed makes them effective pollinators as they transfer pollen from one bloom to another while feeding.

As adults, butterflies drink nectar using their long, tube-like mouthparts called proboscis. This nectar provides them with the carbohydrates needed for energy to fly and reproduce. In their larval stage, caterpillars (the larvae of butterflies) feed on the leaves of specific host plants, obtaining the proteins and nutrients necessary for growth and development into adulthood.

Butterflies are not capable of hovering while feeding. Therefore, they prefer flowers that provide a stable landing platform. Large, flat-topped flowers or small, densely clustered blossoms allow butterflies to land comfortably while they feed on nectar.

Plants that Contribute to the Dietary Needs of Pollinator Butterflies

To attract and support butterflies throughout their life cycle, consider incorporating the following plants into your landscape:

Butterfly Milkweed (Asclepias tuberosa)

Butterfly Milkweed is a perennial plant with vibrant orange flowers that bloom in mid to late summer. Its nectar-rich blossoms attract a variety of butterflies, and it serves as a host plant for monarch butterfly caterpillars, providing essential nutrients during their larval stage by feeding on its leaves.

Marsh Blazing Star (Liatris spicata)

Marsh Blazing Star features tall spikes of purple flowers that bloom in mid to late summer. The densely packed flowers provide ample nectar and are highly attractive to butterflies, offering both a food source and a suitable landing spot.

Buttonbush (Cephalanthus occidentalis)

Buttonbush provides abundant pollen and nectar and serves as a great source of nectar in mid-to late-summer.

These plants supply adult butterflies with the energy sources they need and support caterpillars during their critical growth stages. Providing shelter and water sources will further enhance your garden as a haven for these colorful pollinators.

The Dietary Needs of Other Common Pollinators

While bees, hummingbirds, and butterflies are well-known pollinators, other creatures like moths, flies, wasps, and beetles contribute significantly to pollination. Supporting these pollinators enhances biodiversity and the overall health of your garden.

Moths

Moths are nocturnal pollinators who seem to be attracted to pale or white flowers that open or release scent at night, for example evening primrose (Oenothera biennis).

Flies

Certain flies, such as hoverflies, feed on nectar and pollen and mimic bees in appearance. Plants that supply nectar and pollen useful for flies include Golden Alexanders (Zizia aurea) and Heath Aster (Aster pilosus).

Wasps

While often overlooked, wasps can be effective pollinators. They are drawn to nectar-rich flowers but prefer those with easy access. Narrowleaf Mountainmint (Pycnanthemum tenuifolium) can help support wasps and benefit your garden by preying on pest insects.

Beetles

Beetles are among the oldest pollinators and are attracted to large, bowl-shaped flowers where they feed on pollen. To attract beetles, consider Spicebush (Lindera benzoin).

Support the Dietary Needs of Pollinators with Ernst Seeds

It’s impossible to overstate the importance of pollinators to our ecosystems. Anyone interested in supporting bees and butterflies or simply enjoying the beauty of flowers and the natural landscape can benefit from a better understanding of pollinators’ dietary needs.

If you’re interested in furthering the efforts to reclaim and support local ecosystems in the eastern United States, Ernst Seeds is here to help. 

We have a huge selection of seeds and seed mixes designed specifically to support pollinators and other species. We also have 50 years of experience supporting farmers, gardeners, and landscape architects to build beautiful and sustainable landscapes of all sizes.
Get in touch with us today and find out how we can help with your next project.