Categories: Native Plants

Butterfly Weed: How to Grow This Tough Native Milkweed

Few native plants work as hard as butterfly weed. Its flat clusters of bright orange flowers feed monarchs, bees, and hummingbirds, and the plant shrugs off heat, poor soil, and drought. Despite the name, it isn’t weedy at all. It’s a well-behaved perennial that stays put.

Butterfly weed (Asclepias tuberosa) is a milkweed, which means monarch caterpillars can eat it. It grows wild from southern Ontario to Florida and west to Arizona. For many gardens, that makes it one of the easiest native plants you can choose.

Butterfly Weed at a Glance

Hardiness: USDA zones 3 to 9
Size: 1 to 2.5 feet tall and wide
Bloom time: Early to late summer
Light: Full sun
Soil: Dry to medium, well-drained, sandy or rocky is fine
Wildlife: Monarch host plant; nectar for bees and butterflies

Where to Plant It

Full sun is the main requirement. At least six hours keeps the stems upright and flowering. Butterfly weed also needs drainage. Heavy, wet clay is the most common reason it fails.

It looks great at the front of a sunny border, in a meadow planting, or along a hot driveway. Moreover, it pairs well with other drought-tough natives like coneflowers, little bluestem, and black-eyed Susans.

Monarchs lay their eggs only on milkweeds.

Plant Small, Then Leave It Alone

Butterfly weed grows a long, thick taproot. That root helps it survive drought, but it also means the plant hates being moved. Choose the spot carefully and plant young, potted plants rather than trying to dig up an established clump.

To plant, dig a hole as deep as the pot and slightly wider. Set the plant at the same depth it grew in the container. Water it every few days for the first month, then gradually back off.

Growing From Seed

Seeds need a cold period before they germinate. You can sow them outdoors in fall and let winter do the work. Alternatively, mix seeds with damp sand in a bag and refrigerate them for 30 days before sowing indoors. Expect seedlings to bloom in their second or third year.

Caring for Butterfly Weed

Water

Once established, it rarely needs extra water. In fact, too much water causes root rot. Only water during long droughts in its first summer.

Fertilizer

Skip it. Rich soil makes the stems weak and floppy.

Late Spring Emergence

Butterfly weed is one of the last perennials to wake up. New shoots often don’t appear until late May in northern gardens. Many gardeners assume the plant died and dig right through it. Mark the spot with a stake in fall. Another trick is planting spring bulbs around it, so early color fills the gap and reminds you where it is.

Monarch Caterpillars and Aphids

If you see striped yellow, black, and white caterpillars chewing the leaves, celebrate. Those are monarchs. The plant recovers quickly.

Bright orange oleander aphids are also common on milkweeds. They look alarming but rarely harm the plant. Rather than spraying, rinse them off with a hose or simply let ladybugs and lacewings handle them. Insecticides, even “natural” ones, can kill the caterpillars you’re trying to attract.

Skip insecticides near milkweed to protect caterpillars.

Seed Pods and Fall Cleanup

After flowering, butterfly weed forms slender pods that split in fall and release silky seeds. If you don’t want seedlings, snip the pods before they open. Otherwise, let them be.

When you do your fall garden chores, leave the stems standing. They mark the plant’s location and provide shelter for overwintering insects. Cut them back in early spring instead.

Butterfly Weed in South America

Butterfly weed is native to North America. In much of South America, a related plant, tropical milkweed (Asclepias curassavica), is common in gardens and wild areas. It has red-and-yellow flowers and loves heat. Gardeners in warm regions of Brazil, Argentina, and Colombia often grow it for butterflies. In the southern U.S., however, experts suggest cutting tropical milkweed back in fall so monarchs keep migrating.