How to Plant and Grow Butterfly Weed

Gardeners who love seeing butterflies in their gardens plant butterfly weed (Asclepias tuberosa) for its late spring to late summer clusters of yellow, orange, and red flowers. But the narrow, green leaves of butterfly weed also serve as an important food source for growing monarch butterfly larvae (caterpillars). Native to the Midwest, eastern North America, and the Southern Rocky Mountains, butterfly weed grows in medium-to-dry prairies and other open spaces in gravelly or sandy soils.

If you are lucky, monarch butterflies will find your plants and lay their eggs on the thick, rugged leaves. The foliage of butterfly weed is not only a food source for the growing larvae—it’s also the perfect place to embark upon the process of metamorphosis. This repeating process begins in early summer and continues into the fall when the last generation of butterflies emerge from their chrysalises and migrate to warmer climates.

All parts of the butterfly weed plant are considered mildly toxic to humans, but less so than common milkweed. Some species of milkweed—including butterfly weed—also contain Cardiac glycosides and resinoids, which can be harmful to cats, dogs, and horses.

Where to Plant Butterfly Weed

Depending on the variety, you can plant butterfly weed in small groups or large drifts in USDA
Hardiness Zones 3–11. Butterfly weed is also deer resistant and low maintenance, so it makes the perfect addition to cottage gardens, prairie gardens, or pollinator gardens.

When planting, look for areas with full sun and sandy soil, or add it to sunny garden beds and native habitat gardens. Some varieties of butterfly weed will grow in clay soil, but most prefer well-drained soil.

How and When to Plant Butterfly Weed

Butterfly weed is a hardy perennial that can be planted whenever the ground is workable and plants are available—although fall is the best time to plant nursery-grown or bare-root butterfly weed plants. Dig a hole 12 to 18 inches deep and position the plant crown to sit no more than 1 inch below the soil line. Fill the hole with soil around the root ball or bare roots and water the soil thoroughly.

In spring, butterfly weed leaves often emerge later than other spring garden perennials. So, when weeding your garden in the spring, be careful not to pull out the young plants. Once growth begins, however, the plants seem to appear overnight.

Butterfly weed is also easy to grow from seed if sown in late fall, but they might not flower the first year. Sow the seeds in a prepared and protected garden bed and cover them with 1/4 inch of soil. The seedlings should emerge in late spring. When they reach 3 to 4 inches tall, you can transplant them to their permanent location.

You can also sow seeds indoors in the fall in a moist seed-starting medium. Sprinkle them in a flat and cover them with 1/4 inch of the medium. Moisten again and put the flat in a plastic bag. Put the flat in the refrigerator for four to six weeks to stratify the seeds; then, remove it and place it in a warm area. The seeds should germinate 3 to 4 weeks later. Transplant them to their permanent location when they reach 3 to 4 inches tall.

Butterfly Weed Care Tips

Butterfly weed is beloved for its pollinator-attracting prowess, but it’s also an easy-care herbaceous perennial that is drought-tolerant and adaptable to many environments. It does not spread via runners like common milkweed but can self-seed and spread freely if its seed pods are not removed before they open.

Light

Butterfly weed needs full sun (at least 6 hours per day) to bloom. If your options are limited, butterfly weed can grow in partial sunlight, but plants grown in sunny garden spots will grow more lush and produce more blooms.

Soil and Water

Plant your butterfly weed plants approximately 12 to 18 inches apart in well-drained garden soil. Although they can be grown in most soil types, these plants enjoy sandy soil with a neutral to slightly acidic pH (6.0 to 7.0).

For the first year after planting, plan to give your butterfly weed plants approximately 1 inch of supplemental water each week (in addition to environmental moisture and rainfall). Once established, however, butterfly weed plants are drought-tolerant and may only need monthly watering in very dry climates.

Temperature and Humidity

Butterfly weed is a late spring plant that tends to bloom at the peak of the summer. It thrives best in the temperate climates of zones 3 through 9 but needs the cold stratification period of winter to prepare its seeds for spring germination.

A native plant of the prairies, open woods, and canyons, butterfly weed also has no difficulty growing in arid climates and areas with high humidity.

Fertilizer

Fertilization is not necessary for butterfly weed plants and often causes the plant to grow leggy instead of encouraging it to produce blooms.

Pruning

When the plant dies back for winter, cut the stalks down to within a couple of inches of the ground. You don't have to do this, but it will curtail some of the plant's self-seeding tendencies. During the growing season, you can also deadhead spent blooms to encourage additional flowers.

Potting and Repotting Butterfly Weed

Butterfly weed plants grow well in containers as long as they have ample drainage; sandy, well-draining soil; and daily exposure to full sunlight. Choose a container that is deep enough to accommodate the long, knobby root system of your plant and wide enough to allow for the plant's mature height and width. A deep 10- to 12-inch pot for each plant should be sufficient. When your plant dies back for winter, cut the branches down almost to the soil level. There is no need to repot this plant or refresh the growing medium each year. It thrives in poor soil.

Pests and Problems

Butterfly weed attracts pollinators, but it also attracts an orange aphid called milkweed aphid or oleander aphid. These tiny orange pests will not profoundly damage the plant's health, but they do suck sap from the stalk of the plant and detract from its overall appearance. Milkweed aphids can be treated like other aphids with insecticidal soap or neem oil, but use caution with whatever pest control method you choose as you could inadvertently harm butterfly eggs in the process. Ladybugs can also be introduced to the garden as they are natural predators of the milkweed aphid, but they may also eat the butterfly eggs and larvae in the process.

When grown in wet soil or poorly drained soil, butterfly weed might develop crown rot. To prevent this, don't overwater your plant.

How to Propagate Butterfly Weed

Butterfly weed is excellent at self-seeding in most growing conditions, but it can also be propagated by plant cuttings or with harvested seed.

Propagating via Cuttings

To propagate your butterfly weed in water, take 4- to 6-inch stem cuttings from a healthy, established plant, by cutting it at a 45-degree angle just below a leaf node. Pinch off all but the top two leaves. Fill a clear plastic or glass cup with distilled water and cover the top with clear plastic fastened to the cup with a rubber band. Poke a small hole in the center of the plastic and insert your cutting before placing it in a spot away from direct sunlight. After 1-inch long white roots develop, (about 4 to 6 weeks), pot your cutting in sandy, well-draining potting soil. Fall cuttings give the plant the best start, but the rooted cuttings will have to live indoors for a couple of months after they are potted.

Propagating via Seed

If you want to propagate butterfly weed via seed, you can harvest seed from mature seed pods after the blooming period is complete. Just be sure to collect the pods before they split open and disperse their seeds. Capture the seeds and place them in an envelope or container in a dry, cool area. When the seeds are completely dry, put them in a plastic bag with some moist peat moss and put the bag in the refrigerator for a six-week stratification period. Remove the bag from the refrigerator and plant the seeds indoors in flats or sow them outdoors in a prepared garden bed and cover them in 1/4 inch of soil.

Types of Butterfly Weed

Asclepias tuberosa ‘Hello Yellow’ grows 1 to 2.5 feet tall in a clump and has bright yellow to yellow-orange flowers from mid-spring through summer that attract many butterflies. Its leaves provide food for monarch butterfly caterpillars. Zone 3-9

'Western Gold Mix'

Asclepias tuberosa ‘Western Gold Mix’ is a western Colorado native that is perfect for western gardeners with alkaline soil. Its striking orange flowers attract lots of butterflies, bees, and hummingbirds. This spring bloomer grows to 24 inches tall and 20 inches wide in Zones 4-8.

'Prairie Gold'

Asclepias tuberosa 'Prairie Gold' is a lovely golden yellow butterfly weed native to Indiana. It is striking when grown in mass plantings. It grows to 24 inches tall and 15 inches wide and blooms in summer in Zones 4-9.

'Gay Butterflies'

Asclepias tuberosa ‘Gay Butterflies’ provides gardeners with a mix of brilliant colors of orange, red, and yellow flowers. The flowers grow in dense clusters from June through August on 30-inch-tall plants in Zones 4-11.

Butterfly Weed Companion Plants

Butterfly weed works well in perennial gardens, prairie plantings. and short-to-medium-height borders. Use similar-sized native plants for companions.

'Golden Alexander'

A native prairie plant with yellow flowers, golden Alexander (Zizia aurea) blooms in May and June. It grows in small, tight clumps with many bright flowers on each plant and will tolerate partial shade. This tough native perennial lights up the spring/early summer garden with its bright yellow flowers that attract pollinators. It reaches 24 inches in height and has a low-growing mound habit,

'Little Bluestem'

Short to medium grasses add diversity and texture to your garden. Try little bluestem (Schizachyrium scoparium), a warm-season grass that thrives in native prairie habitats. In fall, its tufts of slim blue-green leaves turn from rust to wine red, and the thin 2- to 3-inch clusters of fuzzy flower spikelets glisten silvery-white in the sun. This rugged, easy-care ornamental grass grows 3 feet tall.

Perennial Salvia

Another small to medium-height plant, perennial salvia (Salvia spp.) ranges from blue to purple to pink blooms in spring, and when cut back after blooming, it blooms again the same summer. Salvias (like the Salvia nemorosa ‘Sensation Rose’ shown here) are also great nectar sources. If you plant them, expect pollinators (especially hummingbirds) to visit your garden.

Garden Plan for Butterfly Weed

No-Fuss Bird and Butterfly Garden Plan

This low-maintenance garden will bring lots of pollinators to your landscape. Tried-and-true favorites, such as catmint, butterfly weed, bee balm, and aster, produce a ton of color all summer into fall while providing the nectar, pollen, and seeds that draw wildlife, including butterflies, bees, and birds. These plants all thrive in full sun and keep on blooming through heat, humidity, and drought. Feel free to add a small birdhouse or a water source, such as a birdbath

Butterfly Garden Plan 

The blossoms in this plan provide nectar for adult butterflies, while leafy food sources nourish the larvae. The butterfly bush is in this plan for a good reason: it lures butterflies of all sorts. A few rocks among the plants provide convenient perches for your winged visitors to sun themselves, and a simple birdbath provides water. Butterflies are sun-loving creatures, as are the plants in this design, so be sure to place this garden where it will receive six or more hours of sun daily.