The Buddleia davidii, commonly known as the Butterfly Bush, has long been a fixture in gardens due to its showy, fragrant flower spikes and its ability to draw adult butterflies. This deciduous shrub, native to China, provides nectar and an attractive visual centerpiece. However, the plant may not be the most ecologically responsible choice, prompting many gardeners to seek alternatives that offer equal beauty and greater biodiversity benefits.
Why Gardeners Seek Alternatives
Gardeners seek alternatives due to two significant ecological concerns. First, the Butterfly Bush is invasive; Buddleia davidii produces thousands of tiny seeds easily dispersed by the wind. This allows it to quickly escape cultivation and colonize disturbed areas, aggressively outcompeting native flora.
Second, the shrub acts as a “nectar trap” because it fails to support the full life cycle of native butterflies. While the flowers provide nectar for adults, the foliage is not palatable to native butterfly and moth larvae (caterpillars). By displacing native host species, the Butterfly Bush can inadvertently reduce the population of the insects it is named for.
Native Shrubs That Mimic Butterfly Bush
Gardeners can achieve the same visual impact and high-nectar reward with native shrubs that actively contribute to the local food web. These alternatives often feature large, showy blooms that attract a wide variety of pollinators.
Summersweet (Clethra alnifolia) is an excellent native replacement, offering fragrant spikes of white or pink flowers in the late summer, similar to the Butterfly Bush. This deciduous shrub is adaptable, thriving in sun or shade and tolerating clay soils, attracting butterflies, bees, and hummingbirds.
Buttonbush (Cephalanthus occidentalis) grows between six and twelve feet tall and produces unique, spherical white or pale-pink blooms from June through September. It provides a significant nectar source, attracting a broad range of beneficial insects and butterflies, and thrives in moist conditions.
For a drought-tolerant alternative, consider New Jersey Tea (Ceanothus americanus), a deciduous shrub with fragrant white, lilac-like flower clusters. While providing nectar for adult butterflies, it also acts as a host plant for Spring Azure butterfly larvae, supporting the full life cycle.
Supporting Life Cycles With Host Plants
A successful butterfly garden must prioritize host plants, which are the specific species on which butterflies lay eggs and whose leaves the emerging caterpillars consume. This is the most significant ecological gap left by the Buddleia davidii, and filling it requires planting species that support the larval stage of growth.
Milkweed (Asclepias species) is the sole food source for Monarch butterfly caterpillars. Various native milkweed varieties, such as Swamp Milkweed (Asclepias incarnata) or Butterfly Weed (Asclepias tuberosa), offer beautiful blooms while ensuring the survival of this iconic species.
The native Spicebush (Lindera benzoin) serves as the host for the Spicebush Swallowtail butterfly and the Eastern Tiger Swallowtail. This deciduous shrub offers aromatic foliage and delicate yellow blooms in early spring, and its leaves are essential for the development of these large swallowtails.
For gardeners in appropriate regions, the native Pawpaw tree (Asimina triloba) is the exclusive host plant for the striking Zebra Swallowtail. While the tree produces the largest edible fruit native to North America, its primary ecological function is providing the necessary leaves for the development of this specific butterfly species’ larvae.
Perennial Flowers for Season-Long Nectar
To complement larger shrubs and host plants, a continuous supply of native perennial flowers ensures nectar is available from spring until the first frost. This supports adult butterflies throughout their entire season of activity, including those preparing for migration.
The following perennials provide season-long nectar:
- Purple Coneflower (Echinacea purpurea) offers broad, purple-pink flowers that attract diverse butterfly species and blooms reliably throughout the summer.
- Bee Balm (Monarda species) features tubular flowers highly attractive to hummingbirds, bees, and butterflies, providing a consistent nectar source from mid to late summer.
- Blazing Star (Liatris species) produces striking purple flower spikes that are known favorites of swallowtails and other larger butterflies.
- Joe Pye Weed (Eutrochium species) contributes to the late-season food supply, featuring large clusters of pinkish-purple blooms that draw in swarms of pollinators from July through September.
- Asters (Symphyotrichum species) and Goldenrod (Solidago species) are paramount for ensuring migrating butterflies have fuel for their journeys. These late-blooming natives provide essential nectar well into the autumn months.