Working the Night Shift: Nectar Plants for Moths

When we garden to encourage pollinator species, we often think about bees, butterflies and other insects that can be seen during daylight hours. Observing the garden “after hours” reveals another world – that of the moths that are active at dusk, at night and into the early dawn.

Why garden with moths in mind?

Moths in all life stages play a vital role in local food webs. They are prey for wildlife including birds, bats, reptiles, other insects, arachnids and mammals. Moths far outnumber butterfly species by about 10:1. In Ontario, we have approximately 3300 described species, with many more yet to be named.
Moths are excellent pollinators; a recent study, published in the journal Biology Letters, found that moths play a vital but overlooked role in pollinating flowers, visiting more plant species than even bees. In addition, their extremely hairy bodies transport more pollen grains than those of other pollinators, and do so over longer distances, increasing plant species’ genetic diversity.
Moth populations are experiencing the same dramatic decline as other insects. A recent article from CTV news in Toronto, for example, warned of the risk of extinction of 20% of pollinators, with many butterflies, bees and moths fluttering into oblivion.
Gardening for moths is incredibly rewarding. Their presence can thrill and confirm we’re making good decisions towards restoring local food webs and a healthy ecosystem.

Note: Moths are not strictly diurnal or nocturnal. Many are crepuscular, most often seen at dusk and dawn. Some are usually nocturnal, but may be seen from time to time nectaring during the day, and some species are strictly diurnal.

Geranium plume moth, most active at night but can be seen during the day

Nectar plants to support moths in our gardens: moth pollination syndrome

To reproduce, moths, like butterflies, require specific larval host plants or groups of plants. Gardeners should be planting with both the adult and the caterpillar in mind. To identify top larval host plants for your ecoregion, visit the National Wildlife Federation’s site Host Plants by Ecoregion. This article describes nectar plants for moths, many of which also may be important larval host plants.

While some moths, like our native Luna moth, don’t feed, others may consume tree sap, rotting fruit, and/or floral nectar. When it comes to nectar, good butterfly plants are good moth plants. After all, butterflies evolved from moths. Most nectar-seeking moths are generalists, visiting popular daytime pollinator plants like blazing stars, mints, Joe Pye-weeds, thistles, echinacea, goldenrods, asters, veronicastrum and so on.

Moths and flowers have co-evolved over millions of years, and some flowers have evolved specific floral traits to purposefully attract crepuscular and nocturnal moths for their pollination services. This combination of traits is referred to as their pollination syndrome, and includes the following:

fragrance at night: a powerful tool to attract moths from long distances, enabling them to locate the flower more easily
pale or white coloration: allows for easier visibility, reflecting moonlight and starlight
tubular or trumpet-shaped flowers with long floral tubes: these complement the long proboscis of many nocturnal moths like sphinx moths which can easily access the nectar
alternate timing: flowers open in the late afternoon or evening and close the following morning. This protects nectar availability for crepuscular and/or nocturnal pollinators.

Recommended plants displaying moth pollination syndrome

Non-native annuals

Though not native to our region, these plants display the floral traits of moth pollination syndrome and have regularly attracted nocturnal moths to my gardens. Unfortunately, there are many hybrids on the market lacking some of the traits described above like fragrance and pale coloration. When growing any of these, stick to straight species (available in seed) or cultivars you know to be effective.

Petunia species:

A member of the nightshade (Solanaceae) family native to South America, petunias can be excellent pollinator plants. Grow in full sun or part shade, and pinch plants back early in the season for bushier growth.

Below, left, Hemaris thysbe, the Hummingbird Clearwing moth, which flies in the daytime, and right, a hawk moth at night, both nectaring in fragrant petunias.

Wild petunia species exhibit different traits (eg. colour and morphology) which are evolved adaptations to attract different pollinators. To attract hummingbirds, for example, try Petunia exserta, red, nonfragrant, below left, which I use to weave through the front of my beds.

But if you want to attract nocturnal moth pollinators, try the white-coloured Petunia axillaris (above right) which has longer floral tubes than other species, and emits an intense fragrance at night. Great as a groundcover or in containers.

Nicotiana species:

Another member of the nightshade family, Nicotianas can be excellent nocturnal pollinator plants. Two species that open in the evening, emitting intense fragrance are N. alata, (below left) with white to greenish blooms, and N. sylvestris, a white-flowering, large, architectural plant (below right). Be careful when purchasing Nicotiana in a garden centre; many flowering tobaccos sold commercially are hybrids, shorter than their parents, with unscented flowers open in the daytime. Plant in full sun or part shade.

Mirabilis species:

Native to South America, Four O’Clocks (Marvel of Peru) open in the late afternoon and emit an overnight lemon-scented fragrance. Below left, M. longiflora ‘Fairy Trumpets’, and right, M. jalapa. Full sun to part shade.

Ipomoea alba (noctiflora) – Moonflower

Last, moonflower is a vine that has large, evening-opening, fragrant, flowers.

Hardy perennials

Oenothera biennis– Evening Primrose

This is our native biennial Evening Primrose which is drought tolerant, and will grow in dry, rocky, disturbed areas. It is best grown on its own in a patch where it can self-sow. The lovely yellow flowers, opening in the evening, are very fragrant until the following morning when they close. While the flowers are short-lived, plants can bloom over several months. Evening Primrose is the larval host of several moths including the White-lined Sphinx and the endearing Primrose Flower Moth. Flower moths (Schinia spp.) are closely linked to their host plants, using them for nectaring, resting, and laying their eggs on the flower buds. Below left, Primrose Flower Moths ‘hanging out’ and nectaring in Evening Primrose flowers, and right, a White-lined Sphinx feeding from Evening Primrose. The white-lined sphinx flies at night and less often during the day.

Other species of note: Oenothera macrocarpa (Missouri evening Primrose), a near-native, is a better-behaved garden plant which also opens in the evening, is fragrant, and attracts nocturnal pollinators. Oenothera pilosella (Meadow Sundrops), a historically popular Carolinian species, opens during the day. It is a shorter plant (40 cm), and has fragrant flowers which attract bees, butterflies and diurnal moths. For more info: Evening Primrose by any Other Name is a Moth Plant | USDA

Honeysuckles (Lonicera spp.)

Our native honeysuckles (Caprifoliaceae family) are excellent moth plants, from the spring blooming shrub Lonicera canadensis (Fly Honeysuckle) with its pale tubular fragrant blooms (below left), to the woody vines L. hirsuta (Hairy Honeysuckle) and L. dioica (Twining Honeysuckle), both early summer bloomers with trumpet-shaped flowers. The near-native woody vine Lonicera sempervirens (Coral Honeysuckle) below right, with its long-tubular orange and yellow flowers is also a beautiful garden plant. Though non-fragrant, its blooms, like those of the other vines above, are moth, butterfly and hummingbird pollinated.

Fly Honeysuckle, shade/part-shade Image: Brett Whaley

Native Phlox Species

Phlox are stunning moth and butterfly-pollinated plants. The fragrant flowers with their long tubes leading to the nectar deep within the flower have evolved for pollinators with a long proboscis. For Mount Cuba botanical garden research trial results of a variety of different species and hybrids, based on plant performance, visit Mt. Cuba Center | Phlox for Sun – Mt. Cuba Center and Mt. Cuba Center | Phlox for Shade – Mt. Cuba Center .

A white-lined sphinx moth (hummingbird moth) takes nectar from a phlox in the daytime, though it is primarily nocturnal. Note the many white lines and the large pink patch on the wings. (Larry Weber photo) www.duluthnewstribune.com

Below are a few recommended varieties for moths.

Phlox paniculata (Garden Phlox) full sun/part shade, mid to late summer bloom

While this tall native phlox species is susceptible to the foliar disease powdery mildew, the two varieties below are resistant. Phlox ‘Jeana’ (below left) has smaller florets than most other P. paniculata varieties, has little to no scent, but has far more pollinator visits in my gardens. ‘David’(below right) is a tall, white, very fragrant, variety, perfect for attracting nocturnal visitors.

Shorter species for full sun to part sun

Left to right, Phlox subulata (Creeping Phlox), growing 15 cm. tall, blooms in late spring to early summer, and P. maculata (Meadow Phlox), growing 60-90 cm. tall, blooms from late summer to fall. Meadow Phlox is less drought-tolerant and should be watered during extended drought.

Photo: Cathy Dewitt, https://plants.ces.ncsu.edu/

Phlox for shade/part shade

Two species with lightly fragrant blooms for woodlands and woodland edges are, below left, the white Phlox divaricata, and right, the shorter Phlox stolonifera (Creeping Phlox), both blooming in spring and making excellent groundcovers.

Native Orchids

According to the Ottawa Orchid Society, there are 43 orchid species in the Ottawa area, many of which are moth-pollinated. Examples are, below left, Platanthera grandiflora, the Large Purple Fringed Orchid. This wetland species is pollinated by swallowtail butterflies and nocturnally, the Large Looper Moth. Below right the Ragged Fringed Orchid, has creamy white coloured flowers which emit a nocturnal fragrance to attract pollinators like sphinx and owlet moths. For more information visit the Ottawa Orchid Sociey

More recommended fragrant natives/near natives:

Small trees: Chionanthus virginicus – Fringe tree, Prunus nigra – Canada Plum

Shrubs: Diervilla lonicera – Bush Honeysuckle, Lindera benzoin – Northern Spicebush, Ribes odoratum ‘Crandall’- Crandall Clove Currant, Viburnum cassinoides– Witherod, Clethra alnifolia– Summersweet Bush, Spiraea alba – Meadowsweet, Hamamelis virginiana – American Witch Hazel

Vines: Clematis virginiana – Virgin’s Bower (hard prune annually)

Forbs: Asclepias spp. – A. exultata– Poke Milkweed, A. incarnata, A. incarnata ‘Ice Ballet’, A. syriaca – Common Milkweed, Solidago odora – Sweet Goldenrod, Euthamia graminifolia – Grass-leaved goldenrod, Eutrochium spp.- Joe-Pye Weeds, Actaea racemosa – Black Cohosh, Pycnanthemum spp. – Mountain Mints, Monarda spp. – Bee Balm