How to Grow Butterfly Weed (Asclepias Tuberosa)
Loved by beneficial bugs, hummingbirds & butterflies
Asclepias tuberosa, commonly called butterfly weed, orange milkweed and butterfly milkweed, is a wildflower native to most of the U.S and Canada. It grows wild in some of the harshest locales, contributing a splash of vivid color in summer to the otherwise dreary, grassy expanses along roadsides, in dry fields and in shale barrens.
A herbaceous perennial, butterfly weed is hardy in USDA Zones 3-10. Its roots and crown live throughout winter, but in colder regions, its tender stems die back and emerge again in spring.
Plant Asclepias tuberosa in an informal herbaceous border, wildflower garden or butterfly garden. Or, use it to add color to the edges of your lawn in that no man's land where turf meets woodland.
Butterfly weed is a relatively short, bushy plant, reaching heights of only 1 to 3 feet tall. From mid to late summer, it produces cheerful clusters of bright orange flowers.
Like milkweed, to whom it is related, butterfly weed attracts hummingbirds, beneficial insects and, of course, butterflies—especially when it's planted in large clumps. It also produces attractive seed pods that ripen in the fall.
full sun to part shade
loamy or sandy
dry to moist
Butterfly Weed in Spring
Keeping Track of Butterfly Weed
Asclepias tuberosa is a herbaceous perennial that's a slow starter. In fact, it will probably be among the last of the herbaceous perennials in your garden to set new growth in the spring. For this reason, you may want to mark its location so that you don't accidentally plant over it.
Because it tolerates a wide range of conditions, Asclepias tuberosa is an easy plant to grow in the home landscape.
Butterfly weed performs best in full sun (6-8 hours per day) but also grows well in partial shade (4 hours per day). It prefers dry soil but will grow in moist soil, too. And butterfly weed does just as well when planted in loam as it does in sandy soil. It doesn't mind an acidic growing medium either, thriving in soil that has a pH anywhere from 4.8 to 6.8.
Transplanting Butterfly Weed
If purchasing Asclepias tuberosa at a greenhouse, be sure to select a young plant. Probably because of their long taproots, mature butterfly weed plants do not transplant well. For this reason, although dividing it every 2 to 3 years will improve the plant's appearance, propagating butterfly weed by division is usually unsuccessful.
The easiest way to start a butterfly weed plant (next to buying a seedling) is to grow it from seed yourself, either sowing Asclepias tuberosa directly outdoors or starting it from seed indoors in the fall or early spring.
Alternatively, if you already have Asclepias tuberosa in your garden, you could let its pods go to seed, allowing the plant to spread on its own. Although mature butterfly weed plants do not transplant well, seedlings do.
Starting Butterfly Weed from Seed
Sow butterfly weed in spring or fall.
Asclepias tuberosa seeds can be sown in the fall or the spring.
Although they won't be large, butterfly weed plants that are started from seed in the fall will flower their first summer. Those sown in spring will develop into larger plants that flower their second summer.
In the Fall
To start Asclepias tuberosa from seed in the fall, begin in August. First, place the seed in a baggie filled with moist peat moss or put it on a damp paper towel and then place it in a plastic bag. Store the seed in the refrigerator for 2 to 3 months. (Like bee balm seeds, coneflower seeds and many others, butterfly weed seed germinates best after stratification, a period of damp coldness.)
After the stratification period, sow butterfly weed seed directly outside. No need to plant deep. About an 1/8 of an inch down will do. It can take as little as 30 days or as long as 90 days for the seed to germinate. During the germination and seedling stages, be sure to keep the ground moist and protected from wind.
If beginning butterfly weed seed indoors, transplant seedlings outside once the weather has warmed and the plants have developed 4 to 6 leaves.
In the Spring
Butterfly weed seed can be started in the same manner in late March or April.
Over the summer, the seedlings will grow into large plants; however, they won't bloom until the following year.
Are you interested in maintaining a butterfly garden?
Planning a Butterfly Garden
When creating a landscape to attract butterflies (and hummingbirds), arrange butterfly weed and other plants that butterflies love in large clumps. Your goal? To create showy flower displays that butterflies will notice.
Also be sure to plant a variety of flowers in your butterfly garden so that something is in bloom at all times from spring into fall.
Butterflies are attracted to many flowering plants in addition to butterfly weed, including asters, bergamot, butterfly bushes, common milkweed, cosmos, dogbane, goldenrod, heliotrope, impatiens, Joe Pye weed, marigold, phlox, Queen Anne's lace, swamp milkweed and zinnia.
© 2012 Jill Spencer