Bloom Period and Seasonal Color
Late summer to fall in colors of orange, red, yellow and pink.
Mature Height x Spread
2 to 4 feet x 2 to 4 feet
Native, attracts hummingbirds, attracts beneficials, drought tolerant, deer resistant
This native has less stature, compared with the butterfly bush, but is just as effective at drawing in winged friends, such a butterflies, ladybugs and beneficial insects, into the garden. It’s particularly a favorite of the Monarch butterfly. Butterfly weed is also hardier and more adapted to a wider range of soils, making it a good choice if you’re having a hard time growing butterfly bush successfully. The plant is slow to emerge in spring, so don’t give up hope. My butterfly weed often will just start growing when other plants are fully leafed out around it. But it makes up for lost time quickly growing to 4 feet tall and wide with brightly colored flowers. Once growing it has few problems.
Where, When and How to Plant
Butterfly weed is hardy through New England. Sow seeds indoors in peat pots 6 to 8 weeks before your last frost date, thinning to one plant per pot. Or plant locally purchased plants in spring after danger of frost has passed or summer, in full sun on compost-amended, well-drained soil. Poor soil drainage is the one thing butterfly weed won’t stand. Space plants 2 to 3 feet apart. Butterfly weed has a taproot, so once planted it’s difficult to move.
Keep the plants well watered the first year and fertilize once in spring with compost. Butterfly weed is slow growing at first in our cool soils, so mark where you planted it so you accidentally don’t dig it up when planting annuals and other perennials in spring.
Regional Advice and Care
Deadhead spent flowers to encourage more flowering and reduce self-sowing. Weed out self-sown seedling each spring. Be carefully when pruning the plant as the stems have a milky sap that might be irritating to your skin. Cutback the plant to the ground in fall after a frost and compost it. It needs little care once established in the garden and can be drought tolerant. Aphids can sometimes be a problem and are easily controlled with sprays of insecticidal soap. Butterfly weed plants can withstand damage from the Monarch butterfly caterpillars. Don’t spray to kill them or you’ll not have any beautiful butterflies.
Companion Planting and Design
Plant butterfly weed in a perennial garden close to where you can view the butterflies from a window or deck. Since butterfly weed can have loud, hot flower colors, pair it in the garden with complimentary colored perennials, such as Russian sage, coneflowers and ornamental grasses. It can also be grown in the cut flower garden for arrangements.
Orange is the native flower color of the hardy, species version and it’s often sold just as Ascelpias tuberosa. “Hollow Yellow” is a yellow flowered version. “Cinderella” has pinkish-red colored flowers. “Gay Butterflies Mix” has plants in colors of red, orange and yellow.
Excerpted from my book, New England Getting Started Garden Guide.