asclepias: milkweed

There are over 200 species of Asclepias worldwide, and more than 70 of those native to North America; about a half-dozen can be found in parts of Oregon. It is highly useful as both a nectar plant for adult butterflies and as a food source for the growing caterpillars.

monarch-caterpillar

The milky substance in the stem and leaves of the plant that give it its common name contains a chemical compound that, when ingested by the caterpillar, acts as a repellant to predators.And some species of the plant are more compatible with specific species of butterflies, in terms of their protective qualities.

This is especially true for the Monarch butterfly and Asclepias speciosa, as it is the only food source for the Monarch caterpillars!

As habitat in the wild is lost to development, maintaining compatible food and nectar supplies for butterflies becomes even more important.

Monarch In May

Besides their usefulness as a butterfly plant, the milkweeds are also beautiful. Leaves broad or thin, standing generally 2-3 feet tall (sometimes taller), with rounded clusters of tiny flowers that look like small stars, often in a mixture of creamy white and pink, sometimes deepening to a rich purple.

Monarch-butterfly egg
Monarch Butterfly eggs on Milkweed

Asclepias requires excellent drainage and a mostly- to full-sun location; yellowing leaves indicate either too much water or poor drainage. Too much retained water can also result in root rot.

But in general, all species of butterfly weed are virtually pest and disease-free (if you notice the leaves on your plant are being eaten, you may have successfully attracted butterflies to your garden!).

Asclepias speciosa (5258350992)

Asclepias speciosa: Showy milkweed

Showy milkweed grows through the Willamette Valley and is the most commonly available Asclepias in nurseries. It also hosts Monarch butterflies at every stage of development! In addition, the nectar provided by its flowers is popular with hummingbirds, bees and other types of butterflies.

Pink flowers bloom from late spring to mid-summer. Blue-green lance-shape leaves are up to 6" long and have a thin layer of white fuzz. Showy milkweed adapts to conditions on both sides of the Cascades, but good soil drainage is important.

Grows to 3’ x 3', Sun, Hardy Z3

asclepias-fascicularis

Asclepias fascicularis: Narrowleaf milkweed

Long, narrow leaves in whorls up the stems of this 2.5’ milkweed. Flowers are generally purplish-pink and white. It grows in dry to moist soil, near streams and at the coast — but note, in sandy (fast-draining) soil.

asclepias-cordifolia

Asclepias cordifolia: Heartleaf milkweed

Elongated heart-shaped leaves, purple flowers arranged in more open, drooping umbels. This one is found in the dry spots of southern Oregon and into California. Extremely drought-tolerant once established, requires next-to-no summer water.

Asclepias incarnata: Swamp milkweed

An exception to the rule: This an Asclepias that grows in wet conditions. Grows 3-4’ tall, narrow green leaves and clusters of bright pink flowers. Not native to Oregon (the farthest west it gets is Idaho, but if you have a wet garden, there is a butterfly weed for you too!)

Find Natives for your garden

We offer a great selection of Northwest Natives from spring through fall. The plants featured are highlighted favorites, but they do not represent ALL of the plants we carry. For a more complete list, see our Northwest Native Plant List.

Natives

Abies: Native Fir

Natives

Acer Circinatum: Vine Maple

Natives

Actaea: Bugbane

Natives

Aquilegia: Columbine

Natives

Arbutus: Pacific Madrone

Natives

Asarum: Wild Ginger

Natives

Asclepias: Milkweed

Natives

Attracting Butterflies

Natives

Camassia: Camas

Natives

Ceanothus: Wild Lilac

Natives

Cornus sericea

Red Twig Dogwood
Natives

Corylus cornuta

Beaked Hazelnut
Natives

Dodecatheon: Shooting Star

Natives

Edible Fruits

Natives

Erigeron: Fleabane

Natives

Eriophyllum: Oregon Sunshine

Natives

Native Ferns

Natives

Fragaria: Wild Strawberry

Natives

Gaultheria shallon: Salal

Natives

Holodiscus: Oceanspray

Natives

Attracting Hummingbirds

Natives

Native Iris

Natives

Lewisia: Bitterroot

Natives

Mahonia: Oregon Grape

Natives

Malus fusca

Western Crabapple
Natives

Osmaronia: Indian Plum

Natives

Penstemon: Beard Tongue

Natives

Philadelphus: Mock Orange

Natives

Physocarpus

Western Ninebark
Natives

Pinus: Native Pine

Natives

Quercus: Garry Oak

Natives

Rhamnus: Cascara

Natives

Ribes: Wild Currant

Natives

Rosa: Wild Rose

Natives

Rubus: Salmonberry

Natives

Sambucus: Elderberry

Natives

Sedum: Stonecrop

Natives

Sidalcea: Checker Mallow

Natives

Sisyrinchium

Blue-eyed Grass
Natives

Solidago: Goldenrod

Natives

Symphoricarpos: Snowberry

Natives

Synthyris: Native Figwort

Natives

Trillium: Wake Robin

Natives

Vaccinium: Huckleberry

Natives

Vancouveria: Inside-out Flower

Natives

Viburnum trilobum

Cranberrybush
Natives

Viola: Violet

Natives

Winter Interest