Native Butterfly Host Plants for the Willamette Valley

Doing some garden planning? Here's a handy dandy list of native plants that support butterfly caterpillars.

The monarch is probably the most well-known butterfly in the world. Unfortunately, its range has also declined considerably. Gardeners are becoming more and more aware that in order to have monarchs, there has to be milkweed - the only plant that the monarch caterpillar will feed on.

The swallowtails also adore milkweed as a nectar plant. This happens to be Asclepias Syriacus - Virginia Silk - from Annie’s Annuals, which is native to the east coast.

But did you know that all butterflies require specific plants to feed their caterpillars? These plants are called host plants, which are different than what butterflies use as nectar plants. Host plants feed the caterpillar, nectar plants feed the butterfly. Often the butterfly will nectar on its host plant, plus a whole range of other plants, which I won’t go into here.

The focus of this post will be on host plants - since there are no butterflies without caterpillars and their associated plants.

Cedar Hairstreak nectaring on non-native “Snowmound” Spirea.

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I have a thing for butterflies and moths. Their visits feel so ethereal. I love observing them up close - their coloring is so cool! I’ve done what I can to expand their habitat on my property.

Moths aren’t as specific about what plants they need, and I’m not typically awake when they are out doing their thing. Since they come out mostly at night and their plant needs are far more extensive, I’ve focused my efforts on learning native butterfly plants.

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First, a few photos to help whet your palate:

A pretty crescent on weedy Ox-eye Daisy.

A grey hair streak nectaring on native sedum spathifolium,

A skipper on non-native Cistus. Swallowtails seem to really like cistus as well.

Pale swallowtails are really common here too. This one is nectaring on non-native Erysimum AKA Wallflower.

Clodius Parnassius nectaring on Pacific Ninebark in my wetland.

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Plant list:

Alder: Western Tiger Swallowtail, Pale Swallowtail, Mourning Cloak, Green Comma

Angelica: Anise Swallowtail

Artemisia: American Lady

Ash: Western Tiger Swallowtail, Snowberry Checkerspot

Betula: Western Tiger Swallowtail, Pale Swallowtail, Green Comma, Mourning Cloak

Bittercress/toothwort (plants in the brassica family) : Sara’s Orangetip, Margined White

Blackberry (trailing, AKA dewberry: Two-banded Checkered Skipper

Bleeding hearts: Clodius Parnassian

Bluebunch Wheatgrass: Woodland Skipper

Broad-leaved Lotus (esp lotus crassifolius, AKA Hosackia Crassifolia): Bramble Green Hairstreak, Silver Spotted Skipper, Persius Duskywing

Bromes: Juba Skipper

Buckwheats: Mormon Metal mark, Gray Hairstreak, Brown Elfin, Acmon Blue

Carrot family: Anise Swallowtail (69 host plants including natives and garden vegetables)

Cascade Aster: Field Crescent

Cascara: Pale Swallowtail, Brown Elfin

Castilleja: Edith’s Checkerspot

Ceanothus: Pale Swallowtail, Echo Azure, Lorquin’s Admiral, California Tortoiseshell, Brown Elfin

Cedars (Western and Incense Cedar): Cedar Hairstreak

Celery-leaf lovage: Anise Swallowtail

Checkermallow: Painted Lady, West Coast Lady, Common Checkered Skipper, Two-Banded Checkered Skipper, Gray Hairstreak

Cherry (native Bitter and Chokecherry): Western Tiger Swallowtail, Pale Swallowtail, Echo Azure, Lorquin’s Admiral

Cinquefoil: Purplish Copper, Two-Banded Checkered Skipper

Clovers: Orange Sulfur, Eastern Tailed Blue, Gray Hairstreak, Persius Duskywing, Orange Sulfur

Collinsia: Edith’s Checkerspot

Cow Parsnip: Anise Swallowtail

Doug Fir: Pine White

Elderberries: Echo Azure

Fescues: Common Wood Nymph, Sonora Skipper

Geum: Two-Banded Checkered Skipper

Grand Fir: Pine White

Grasses, unspecified native plants in our area Ochre Ringlet, Sonoran Skipper, Sachem, Arctic Skipper, Common Roadside Skipper

Hairgrasses: Juba Skipper

Hawthorne: Pale Swallowtail , Mourning Cloak

Hemlock: Pine White

Huckleberry: Brown Elfin, Echo Azure

Kinnikinnick: Brown Elfin

Lomatium: Anise Swallowtail

Lonicera: Snowberry Checkerspot, Edith’s Checkerspot

Lotus: Acmon Blue, Persius Duskywing, Gray Hairstreak, Western Tailed Blue, Silvery Blue

Lupines: Orange Sulfur, Silvery Blue, Eastern Tailed Blue, Acmon Blue, American Lady, Painted Lady, Persius Duskywing, Boisduval’s Blue, Orange Sulfur

Madrone: Brown Elfin, Echo Azure

Maples (Big Leaf, Vine, Douglas Maples): Western Tiger Swallowtail, Mourning Cloak

Manzanita (including Kinnikinnick): Brown Elfin, Echo Azure

Milkweeds: Monarch

Mimulus Guttatus: Mylitta Crescent, Snowberry Checkerspot, Edith’s Checkerspot

Mistletoe (on oaks): Great Purple Hairstreak

Mistletoe (on Hemlock and Doug Fir): Johnson’s Hairstreak

Oak: California Sister, Propertius Duskywing, Gray Hairstreak

Oceanspray: Pale Swallowtail, Echo Azure, Lorquin’s Admiral

Oregon Grape: Brown Elfin

Orthocarpos: Edith’s Checkerspot

Pea: Western Tailed Blue, Eastern Tailed Blue, Silvery Blue, Orange Sulfur

Pearly Everlasting: American Lady

Penstemmon: Snowberry Checkerspot, Edith’s Checkerspot

Pine trees: Pine White

Polygonums: Purplish Copper, Gray Hairstreak

Poverty Oat Grass: Common Wood Nymph, Woodland Skipper

Poplars (cottonwoods): Western Tiger Swallowtail, Lorquin’s Admiral, Mourning Cloak

Redtwig dogwood: Echo Azure

Rhododendron: Green Comma, Hoary Comma

Ribes (currant, gooseberry): Pale Swallowtail, Oreas Angelwing, Green Comma, Tailed Copper, Hoary Comma

Rockcresses: Julia’s Orange tip, Western White

Roses: Mourning Cloak, Lorquin’s Admiral

Rumex species: Purplish Copper, Great Copper, Gray Hairstreak

Rushes: Ochre Ringlet

Salal: Brown Elfin

Sedges: Ochre Ringlet, Dun Skipper, Common Ringlet, Dun Skipper

Sedums: Brown Elfin, Gray Hairstreak

Serviceberry: Pale Swallowtail, Brown Elfin, Lorquin’s Admiral

Snowberries: Snowberry Checkerspot

Spiraea Douglasii (and other spiraeas): Pale Swallowtail, Echo Azure, Mourning Cloak, Lorquin’s Admiral

Stinging Nettle: American lady, West Coast Lady, Red Admirable, Milbert’s Tortoiseshell, Satyr Angelwing, Green Comma, Painted Lady

Strawberry: Two-Banded Checkered Skipper, Gray Hairstreak

Sweet Cicely: Anise Swallowtail

Thermopsis: Persius Duskywing, Western Tailed Blue

Thistles: American Lady, Painted Lady, Mylitta Crescent

Toothworts: Mustard White, Western White, Sarah’s Orange tip

Watercress: Margined White, Western White

Water Parsnip: Anise Swallowtail

Western Crabapple: Western Tiger Swallowtail, Pale Swallowtail, Brown Elfin, Mourning Cloak, Lorquin’s Admiral

Willows: Western Tiger Swallowtail, Lorquin’s Admiral, Mourning Cloak, mma

Vetches: Silvery Blue, Eastern Tailed Blue, Western Tailed Blue, Gray Hairstreak

Viburnum: Echo Azure

Violets: Western Meadow Fritillary, Great-spangled Fritillary, Hydaspe Fritillary, Zerene Fritillary

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Resources:

Butterflies of the Pacific Northwest (book)

Life Histories of Cascadia Butterflies (book)

https://www.butterfliesoforegon.com/

www.calscape.org

www.pnwflowers.org

www.butterfliesandmoths.org

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