Black Swallowtail Host Plants

Black Swallowtail

Anise – Pimpinella anisum

Caraway – Carum carvi

Celery – Apium graveolens

Cow Parsnip – Heracleum maximum

*Dill – Anethum graveolens

Dutchman’s Breeches – Thamnosma texanum

*Fennel – Foeniculum vulgare

Forked Scaleseed – Spermolepis divaricata

Golden Alexander – Zizia aurea

Mock Bishopweed – Ptilimnium capillaceum

Northern Water Hemlock – Cicuta virosa (Extremely poisonous deadly plant)

*Parsley – Petroselinum crispum

Parsnip – Pastinaca sativa

Poison hemlock – Conium maculatum

*Queen Anne’s lace – Daucus carota

Roughfruit Scaleseed – Spermolepis divaricata

*Rue – Ruta graveolens

Slender Celery – Cyclospermum leptophyllum

Yarrow – Achillea millefolium

Water Cowbane – Oxypolis filiformis

*Water Hemlock – Cicuta maculata (Extremely poisonous deadly plant)

Water Parsnip – Berula erecta

Wedgeleaf  Eryngo – Eryngium cuneifolium

*Wild Carrot – Daucus carota 

Wild Chervil – Cryptotaenia canadensis,

We have personally used the plants with an * by the name.  The other listed host plants are gathered from experiences of others.  We do not guarantee that caterpillars will eat plants we have not listed.

Black Swallowtails do not always change host plants.  Host plants within the same group (parsley, dill, fennel) usually do not cause problems.  Changing to rue from another plant is often difficult to impossible.  Changing from other plants to highly toxic water hemlock is sometimes fatal for caterpillars.  If they begin eating the leaves of water hemlock when they are young, they do well on water hemlock.

Information was gathered by personal experience, the Association for Butterflies, Rick Mikula (The Butterfly Guy), various books, and the internet.