Best host plants for swallowtail butterflies

Swallowtail butterflies are among the largest and most recognizable butterflies in North America. Unlike generalists that use many host plants, most swallowtail species have specific host plant requirements -- some highly specific, others moderately so. Per Xerces Society, planting the correct host.

—- title: "Best host plants for swallowtail butterflies" slug: best-plants-for-swallowtail-host hub: plants category: "Plant list" description: "Best host plants for swallowtail butterfly larvae: species-specific plants for eastern, black, tiger, spicebush, and pipevine swallowtails with zones and care notes." date: 2026-06-10 updated: 2026-06-10 author: "Thomas A." reading_time: 10 —-

Swallowtail butterflies are among the largest and most recognizable butterflies in North America. Unlike generalists that use many host plants, most swallowtail species have specific host plant requirements — some highly specific, others moderately so. Per Xerces Society, planting the correct host species for the swallowtails native to your region is far more effective than planting generalist nectar sources.

This guide addresses five North American swallowtail species and their host plant requirements, sourced primarily from Xerces Society and University of Florida IFAS lepidopteran host plant databases.

—-

Eastern Tiger Swallowtail (Papilio glaucus) hosts

1. Liriodendron tulipifera (Tulip Tree)

Zones 4–9 | Full sun | Height: 60–90 ft

Per Xerces Society, tulip tree is one of the most important host trees for eastern tiger swallowtail in the eastern US. The large scale of the tree means caterpillar damage is essentially invisible in a landscape tree. Per Missouri Botanical Garden, it is also an outstanding ornamental tree with large tulip-shaped flowers and excellent fall color.

2. Prunus spp. (Wild Cherry, Black Cherry)

Zones 3–9 | Full sun | Height: 30–80 ft

Per Xerces Society, wild cherry species (Prunus serotina, P. virginiana) are primary eastern tiger swallowtail hosts. They are also used by several other swallowtail species. Ornamental cherry cultivars are functional hosts; the native wild cherries are preferred for their additional wildlife value.

3. Magnolia virginiana (Sweetbay Magnolia)

Zones 5–10 | Full sun to part shade | Height: 10–35 ft

Per UF IFAS Extension, sweetbay magnolia is a documented host for eastern tiger swallowtail. Semi-evergreen in zones 7–10, deciduous in colder zones. Lemon-scented white flowers in May–July.

—-

Black Swallowtail (Papilio polyxenes) hosts

4. Daucus carota (Queen Anne's Lace — host plant)

Zones 3–9 | Full sun | Height: 2–4 ft (biennial)

Per Xerces Society, Queen Anne's lace (Daucus carota) is among the most frequently used black swallowtail host plants in residential gardens. Allow it to naturalize in a meadow or informal area. The larvae are recognizable: green and black banded with yellow spots.

5. Petroselinum crispum (Parsley — host plant)

Annual/biennial | Full sun | Height: 12–18 inches

Per Xerces Society and UF IFAS Extension, parsley is a primary black swallowtail host. Planting extra parsley (beyond what you need for culinary use) specifically as a host plant is one of the most practical contributions a residential gardener can make for this species.

6. Foeniculum vulgare (Fennel — host plant)

Zones 4–9 | Full sun | Height: 4–6 ft

Per Xerces Society, fennel is heavily used by black swallowtail caterpillars. Bronze fennel (F. vulgare 'Purpureum') is ornamentally attractive as well as functional. Direct-sow in spring and allow to naturalize.

7. Zizia aurea (Golden Alexander)

Zones 3–8 | Full sun to part shade | Height: 18–36 inches

Per Xerces Society and Illinois Extension, golden Alexander is one of the best native black swallowtail hosts. Small yellow flowers bloom in April–May (one of the earliest native perennials to bloom), providing both larval host and early nectar. A native prairie plant that tolerates moist to dry conditions.

—-

Pipevine Swallowtail (Battus philenor) hosts

8. Aristolochia macrophylla (Dutchman's Pipe Vine)

Zones 4–8 | Full sun to part shade | Height: 20–30 ft (climbing)

Per Xerces Society and Penn State Extension, Dutchman's pipe vine is the primary host plant for pipevine swallowtail in the eastern US. The larvae store pipevine toxins from Aristolochia in their body tissue, making both caterpillars and adults unpalatable to predators. A large-leaved twining vine that covers a trellis or fence rapidly.

9. Aristolochia tomentosa (Woolly Dutchman's Pipe)

Zones 5–8 | Full sun to part shade | Height: 20–30 ft (climbing)

Per Missouri Botanical Garden, woolly Dutchman's pipe is a native alternative to the more commonly sold A. macrophylla and supports the same pipevine swallowtail larvae. The large velvety leaves and unusual pipe-shaped flowers are ornamentally interesting.

—-

Spicebush Swallowtail (Papilio troilus) hosts

10. Lindera benzoin (Spicebush)

Zones 4–9 | Part shade | Height: 6–12 ft

Per Xerces Society, spicebush is the primary and preferred host for spicebush swallowtail. This native shrub blooms in March–April before its leaves, bearing tiny yellow flowers along bare stems. Yellow fall foliage, red fall berries for birds. An outstanding multi-season native shrub with direct conservation value.

11. Sassafras albidum (Sassafras)

Zones 4–9 | Full sun | Height: 30–60 ft

Per Missouri Botanical Garden, sassafras is a secondary host for spicebush swallowtail and a primary host for eastern tiger swallowtail. Its distinctive mitten-shaped leaves have variable lobing. Outstanding fall color in orange-red-purple. Spreads by root suckers to form thickets — most suitable for naturalized areas.

—-

Giant Swallowtail (Papilio cresphontes) hosts

12. Ptelea trifoliata (Hoptree / Wafer Ash)

Zones 4–9 | Full sun to part shade | Height: 15–20 ft

Per Xerces Society and Missouri Botanical Garden, hoptree is a native small tree in the citrus family (Rutaceae) and an important giant swallowtail host plant in the eastern US. Attractive bark, fragrant flowers, and distinctive disc-shaped seeds. One of the more underused native small trees with direct butterfly conservation value.

—-

Companion nectar plants for swallowtails

Per Xerces Society, adult swallowtails are highly attracted to these nectar plants: Phlox paniculata (garden phlox), Lantana camara, Buddleja spp. (butterfly bush, but note its invasive status in some states), Asclepias spp. (milkweed), and Echinacea purpurea (coneflower). Plant host plants and nectar plants together to support the complete swallowtail lifecycle.

—-

Frequently Asked Questions

Will caterpillars damage my parsley crop? Per Xerces Society, black swallowtail caterpillars can defoliate parsley completely. Plant extra specifically as a host (2–3 plants for cooking, 2–3 plants as host) to ensure adequate culinary supply while supporting the species. Damage occurs in summer when caterpillar populations peak.

How do I identify swallowtail eggs and young caterpillars? Per UF IFAS Extension, swallowtail eggs are round, pale yellow-green spheres placed singly on host plant leaves. Early instar larvae mimic bird droppings (brown and white); later instars are banded green-and-yellow or green-and-black depending on species. Do not remove eggs or small caterpillars from host plants.

Is fennel invasive? Per Oregon State Extension, common fennel (Foeniculum vulgare) is considered invasive in California and parts of the Pacific Northwest. In the eastern US and Midwest, it self-seeds but is not typically problematic. Check your regional invasive species list before planting.

Can I plant Dutchman's pipe on a wood fence? Per Penn State Extension, Aristolochia vines are vigorous and heavy when mature. They require a sturdy trellis or support structure — wood privacy fencing is generally adequate if the fence posts are well-anchored. Large leaf mass creates wind resistance.

—-

Sources

1. Xerces Society — Swallowtail Host Plants
2. UF IFAS Extension — Butterfly Host Plants
3. Missouri Botanical Garden — Plant Finder
4. Penn State Extension — Native Vines
5. Illinois Extension — Native Prairie Plants
6. Oregon State Extension — Fennel