Adult caterpillars in the order Lepidoptera are butterflies and moths, often either notoriously beautiful or very dull insects as adults. Species in the order Lepidoptera undergo complete metamorphosis, meaning that their juvenile form looks entirely different from their adult form.
As juveniles, all butterflies and moths are larvae with three true legs located toward the front of the body and two to five pairs of prolegs towards the back end of the insect. These larvae are known as caterpillars, and they have various forms and colors. Caterpillars are herbivorous and consume plant material. As adults, Lepidopterans generally consume nectar, but some species are known to consume mud, sweat, or even the blood of other animals.
Flowers attract butterflies via showy petals that promise nectar deeper within the flower. In exchange for a sweet meal, the butterfly will transfer pollen from one flower to another, helping that flower produce seeds and continue the next generation. Planting butterfly-friendly plants means attracting beautiful butterflies to a garden, but sometimes butterflies will lay eggs on the flowers they visit.
1) Milkweed (Asclepias spp.)
Milkweeds belong to the genus Asclepias in the family Apocynaceae, which includes about 73 species native to North America. Milkweeds are essential plants for pollinators, particularly the monarch butterfly (Danaus plexippus). Depending on the species, milkweed plants can range in size from a few inches tall to over 6 feet tall (2 m). One plant in the genus Calotropis can grow to over 15 ft (4.6 m)!
The leaves are typically broad and oval-shaped, and the flowers are large and showy, with five petals that are often pink or purple. Milkweed contains a toxic cardiac glycoside, which can be harmful or fatal to animals if ingested in large quantities. These cardiac glycosides are ingested by monarch caterpillars, making them toxic to other animals. As a result, monarch caterpillars are vibrantly colored, like a dangerous wasp, to warn predators of their toxicity. This type of coloration is known as aposematic coloration.
2) Passionflower (Passiflora spp.)
Passionflowers are known for their intricate and exotic-looking flowers, as well as their fruit, which is called a passion fruit and is a popular fruit in North and South America. Passionflower blooms are incredibly unique and visually stunning. The flowers typically have a complex structure with five petals and five sepals. The petals come in various colors, including shades of white, pink, purple, blue, and red.
The most distinctive feature of passionflower flowers is the arrangement of filaments and stamens, which form a central column and a fringe of colorful, thread-like structures. Passionflower vines can be trained to grow on a variety of surfaces. They are also a host plant for fritillary butterflies (Euptoieta spp.).
3) Dill (Anethum graveolens)
Dill is an herb that produces small, yellow flowers in clusters called umbels. These flowers are attractive to butterflies, such as the black swallowtail butterfly (Papilio polyxenes), which uses dill as a host plant. Dill is also high in vitamin C and other nutrients, making it a great meal addition. It is excellent in pesto, potato salad, chicken, and fish.
Growing dill is easy, and there are many varieties to pick from that vary in overall size, leaf size, and number of flowers. As with most other herbs, dill prefers full sun and well-draining soil. Once well established, dill is hardy and will not require intensive care.
4) Chokecherry (Prunus virginiana)
The chokecherry is known for its tart berries and is valued as both an ornamental and a culinary plant. Chokecherry typically grows as a multi-stemmed shrub or a small tree, reaching a height of 10 to 25 feet (3 to 7.6 meters) at maturity. The leaves are simple and the flowers are small and white, but are attractive to bees and other pollinators. The berries are edible and are used in jams, jellies, pies, and sauces.
In addition to attracting butterflies and bees, the chokecherry also attracts songbirds which hide amongst the branches and eat the berries. Finally, the chokecherry is a host plant for the two-tailed swallowtail (Papilio multicaudata) and the tiger swallowtail (Papilio glaucus) which produce large orange and green caterpillars.
5) Parsley (Petroselinum crispum)
Parsley is not only valued for its culinary uses but also for its nutritional benefits. It is a rich source of various vitamins, minerals, and antioxidants. It is often used as a garnish, added to salads, soups, stews, and sauces, and can even be used in juicing or as a key ingredient in pesto.
The black swallowtail (Papilio polyxenes) can use parsley as a host plant. If you find caterpillars on your parsley plants and wish to protect them, you can manually remove the caterpillars and relocate them to a different area or provide them with alternative food sources.
6) Lupine (Lupinus spp.)
With an interesting towering arrangement of flowers, lupines possess vibrant flowering structures that come in an array of purple, pink, and even orange. The frosted elfin (Callophrys irus) caterpillar uses the sundial lupine as a host plant. Wild indigo (Baptisia spp.) is another group of plants that host the frosted elfin.
Other gossamer-winged butterflies in the family Lycaenidae use lupine and wild indigo as host plants. Growing lupine is straightforward. The plant enjoys moist, well-draining soil and cooler temperatures. It thrives in growing zones 4 – 6 and, while it will grow during the cooler months in zones 7-9, the summer heat in these regions will kill lupine.
7) Smooth aster (Symphyotrichum laeve)
Smooth asters attract many different pollinator species and are a host plant for the pearl crescent (Phyciodes tharos), painted lady (Vanessa cardui), and silvery checkerspot (Chlosyne nycteis) butterflies. This perennial aster is native to North America and is known for its beautiful clusters of small, daisy-like flowers with vibrant purple or blue petals. The leaves are smooth, hence the name “smooth aster,” and they have serrated edges.
Smooth aster blooms from summer to fall, typically from August to October, and it is commonly found in prairies, meadows, open woodlands, and along roadsides. It is well-suited for perennial borders, wildflower meadows, and naturalized areas. It can also be combined with other late-season blooming plants to extend the blooming season in the garden.
8) Columbine (Aquilegia spp.)
Columbines, also known as Aquilegia, are beautiful flowering plants that belong to the Ranunculaceae family. They are native to the Northern Hemisphere and can be found in various regions, including North America, Europe, and Asia. Columbines are popular garden plants due to their unique and distinctive flowers.
Columbine flowers have a distinct shape that resembles a cluster of elongated, spurred petals. The petals are often bi-colored or multi-colored, with combinations of white, yellow, pink, red, purple, and blue. The inner petals often contrast with the outer petals, creating an eye-catching display. While most species of columbine attract butterflies, the eastern red columbine is the host plant for the columbine duskywing (Erynnis lucilius), a small brown moth with green caterpillars that have characteristic black heads.
9) Roundheaded bush clover (Lespedeza capitata)
Roundheaded bush clovers are North American native perennial plants that produce attractive clusters of white to pale pink flowers on tall stalks. The caterpillars of the orange sulfur butterfly (Colias eurytheme) and the eastern tailed-blue (Cupido comyntas) have been observed feeding on the leaves of roundheaded bush clover and other plants in the pea family (Fabaceae).
While it can be a host plant for several species of caterpillar, the roundheaded bush clover’s primary value lies in its nectar-rich flowers, which attract a wide range of pollinators, including butterflies. Its inclusion in butterfly gardens and native plant landscapes can provide essential resources for these insects and contribute to their conservation efforts. This plant prefers dry soils and full sun.
10) Black-eyed Susan (Rudbeckia hirta)
Black-eyed Susans are one of the most common flowering plants in North America. They have characteristic yellow blooms with large, brown centers. After the flowering season, the petals wither and leave behind a brown center full of seeds.
The black-eyed Susan is a host plant for the silvery checkerspot (Chlosyne nycteis) and bordered patch (Chlosyne lacinia) butterflies. In addition, they provide nectar for many other native pollinators. Black-eyed Susans are usually found in open grassy areas where they can get plenty of sun, but they are also hardy in the home garden.
11) Fennel (Foeniculum vulgare)
Fennel produces flower clusters called umbels and is another herb with tiny flowers that attract beneficial insects, including parasitic wasps and ladybugs. Like dill, black swallowtails use fennel as a host plant. Fennel seeds are also commonly used spices added to dishes to provide a sweet taste to curries, desserts, and bread.
As with other Mediterranean herbs, fennel should be grown in full sun in soils that are well-draining. They can be grown indoors to get ahead of the growing season, but they are not the best herb to transplant to the garden because they develop a tap root as seedlings. Therefore, sowing them directly into the garden or starting them in a large pot indoors is best.
12) Spicebush (Lindera benzoin)
Spicebush is native to the understory of moist woodlands, along stream banks, and in wetland areas of eastern North America. Spicebush thrives in moist to wet soils and prefers partial shade to full shade. It is adapted to a variety of soil types, including loam, clay, and sandy soils making it a good choice for forested woodlands. Spicebush is also beneficial for many wildlife species as the flowers and fruits provide food for pollinators, birds, and other wildlife.
The twigs and leaves of spicebush have a spicy, aromatic flavor and can be used as a seasoning in cooking. They can be dried and used as a substitute for allspice or added to teas and infusions. Spicebush hosts the spicebush swallowtail butterfly (Papilio troilus) whose caterpillars feed on the plant.
13) Willow (Salix spp.)
Willows are water-loving trees with long, drooping leaves that create a unique, umbrella-like appearance. There are many different species and cultivars of willow trees, each with its unique growth characteristics and requirements. Willows are host plants for various butterfly species, including the mourning cloak (Nymphalis antiopa) and viceroy (Limenitis archippus).
The caterpillars of the mourning cloak butterfly feed on the leaves of various willow species, including black willow (Salix nigra) and pussy willow (Salix discolor). Additionally, the caterpillars of some comma butterfly species, including the eastern comma (Polygonia comma) and the green comma (Polygonia faunus), use willow trees as host plants.
