Butterfly Milkweed (Asclepias tuberosa)

How much light does a Butterfly Milkweed need?

Butterfly milkweed prefers full sun and also accepts part shade. Full sun means 6 or more hours of direct sunlight a day. Part shade means direct sunlight for only part of the day, about 2 to 6 hours. Plan for at least 6 hours of direct sun per day.

• Light: Full sun and part shade (full sun preferred)^1,2
• Direct sun: 6 h/day^1,3

How often to water a Butterfly Milkweed

Butterfly milkweed takes soil that is dry to medium in moisture. It is drought-tolerant and does well in poor, dry soils. It is also moderately salt-tolerant. Check the soil rather than a calendar, because dry to medium, well-drained ground is the target. Avoid soggy ground, since the central taproot is prone to rot in poorly drained soil.

• Water: Dry to medium^4,1

Best soil for a Butterfly Milkweed

Plant butterfly milkweed in well-drained soil that ranges from dry to moist. The suitable conditions listed are well drained, moist and occasionally dry. Avoid poorly drained or soggy soil, since the central taproot is prone to rot. Poor, dry soils also suit it. Dry to medium soil moisture is the range given for this species. No cited source records a soil pH range for this plant. A deep, wet mulch layer may cause crown rot.

• Soil drainage: Well drained, moist and occasionally dry^5,6

Hardiness and temperature

Butterfly milkweed is hardy in USDA zones 3a to 9b. Zone 3a is the cold end of that range and zone 9b is the warm end. Gardeners in zone 3a and in zone 9b both fall inside the listed range. The plant is native in the lower 48 US states.

• Hardiness: Zones 3a–9b²

Pruning a Butterfly Milkweed

The pruning task listed for butterfly milkweed is deadheading. Remove seedpods before they dry and split if you want to avoid self-seeding. The plant is erect, 1–2 ft (0.3–0.6 m) tall, and about 1–1.5 ft (0.3–0.46 m) wide at maturity. Its growth rate is slow.

• Pruning: Deadheading⁶

How to plant a Butterfly Milkweed

Plant butterfly milkweed in USDA zones 3a to 9b. Choose a spot with 6 or more hours of direct sunlight a day. The soil should be well drained, since the central taproot is prone to rot in poorly drained or soggy soil. Allow for a mature width of 1 to 1.5 ft (0.3–0.46 m). A mature plant stands 1–2 ft (0.3–0.6 m) tall. Avoid a deep, wet mulch layer, which may cause crown rot.

• Hardiness: Zones 3a–9b²

Winter care

Butterfly milkweed is listed as hardy to zone 3a at the cold end. Zones 3a to 9b are the range given for it. No cited source records a minimum temperature or specific winter protection. A deep, wet mulch layer may cause crown rot. The plant is a herbaceous perennial. Poorly drained or soggy soil is also a hazard, since the taproot is prone to rot. Its erect habit reaches 1–2 ft (0.3–0.6 m).

• Hardiness: Zones 3a–9b²

How to propagate a Butterfly Milkweed

You can propagate butterfly milkweed from seed or from root cuttings. The plant is a herbaceous perennial with a central taproot. For seed, it is best to direct seed into the landscape. Both seeds and root cuttings are listed as propagation material for the species. If you do not want seedlings, avoid self-seeding by removing seedpods before they dry and split.

• Propagation: Seed and root cuttings^5,4

Common problems

Aphids and oleander aphid are the pests listed for butterfly milkweed. Aphids may be a problem. Root rot and crown rot are the diseases listed. A deep, wet mulch layer may cause crown rot. The central taproot is prone to rot in poorly drained or soggy soil.

• Common pests: aphids and oleander aphid⁴
• Common diseases: root rot and crown rot⁴

Questions and answers

Is butterfly milkweed toxic to cats and dogs?

The ASPCA lists it as toxic to cats and toxic to dogs. The position is the same for both animals. It is an erect herbaceous perennial about 1–2 ft (0.3–0.6 m) tall.

How much sun does butterfly milkweed need?

It prefers full sun, which means 6 or more hours of direct sunlight a day. It also accepts part shade, with direct sunlight for only part of the day.

What kind of soil does butterfly milkweed need?

It needs well-drained soil that ranges from dry to moist. Avoid poorly drained or soggy soil, since the central taproot is prone to rot. Soil moisture in the dry to medium range suits it.