Asclepias incarnata (Swamp Milkweed), A. tuberosa (Butterflyweed), A. syriaca (Common Milkweed) are all native to North America.
The common names (Milkweed, Butterflyweed, etc) usually refer either to the plant’s milky white sap or its famous attraction for pollinators.
The botanical name, Asclepias, is derived from Asclepius, the Greek god of medicine, since the roots of many of the plants were used for various medicines by native peoples.
Growing and Cultivation
Asclepias prefers full sun and average to dry soil – while it doesn’t like to have ‘wet feet’, it will tolerate drought periods once established. Prefers soil on the sandy, well-drained side.
Plants are slow to emerge in spring, so don’t despair if they seem dead! Overfertilization can inhibit flowering, so be careful! Deadheading the flowers will encourage a rebloom.
Will self-seed unless seed pods are removed while still closed. A. incarnata has a deep taproot, so is difficult or impossible to transplant once fully grown. Please choose a spot wisely.
Common Pests and Diseases
Can be susceptible to Rust and Leaf Spot. A. incarnata can be susceptible to Orange Milkweed Aphids.
Almost all Asclepias species are deer and rabbit resistant. The milky sap and rough textures make them unappealing to eat.
Interesting Facts and Uses
Some Native American peoples still use the tough fibers from the stems of milkweeds for rope, twine, or weaving nets or cloth. Before sugar, Native Americans also used the nectar as a sweetener.
During WWII, large amounts of milkweeds were grown for their seed floss to stuff pillows and life jackets. Called comas, these are five times warmer than wool, and six times more buoyant than cork! The floss is still used commercially to create some hypoallergenic pillows.
- incarnata (Swamp Milkweed) is poisonous to livestock, particularly sheep. A. incarnata is said to have a slight vanilla scent, and can be used as a cut flower after searing the stems to prevent sap dripping.
- tuberosa (Butterflyweed) does not contain milky sap in its leaves, and can also be used as a cut flower.
All Asclepias species are fantastic (and almost necessary!) plants for a pollinator garden! They are the primary, if not only, host plant for Monarch butterfly larva (caterpillars) as well as a nectar source for eastern tiger swallowtails, fritillaries, hairstreaks, skippers, spicebush swallowtails, buckeyes, painted ladies, pipevine swallowtails, and other butterflies! They also attract and feed honeybees, hummingbird moths, and hummingbirds themselves!
Milkweeds can also be beneficial to nearby plantings; it repels some soil pests, including wireworms.
Garden Design Tips
Asclepias adds a bold texture to garden beds. Complement your plants with more delicate, ferny foliage and soft colors with milkweed’s large leaves and bright colors!
To purchase Asclepias varieties, please visit our Sun Companion Plants Page.