Butterfly weed Asclepias tuberosa
Butterfly weed (Asclepias tuberosa) is a deciduous perennial flowering plant in the Apocynaceae family, native to Eastern and central North America. It grows 50–90 cm (20–35 in) tall and 40–60 cm (16–24 in) wide, wants full sun and low water, and is hardy to about -34 °C (-29 °F). Space plants about 50 cm (20 in) apart.
Plan Butterfly weed in your garden →
Free. Draw your beds, then watch it grow through the year in 2D and 3D.
Butterfly weed at a glance
| Type | Perennial flowering plant, deciduous |
|---|---|
| Family | Apocynaceae |
| Mature height | 50–90 cm (20–35 in) |
| Mature spread | 40–60 cm (16–24 in) |
| Spacing | 50 cm (20 in) centre to centre |
| Sun | Full sun, at least 6 h of direct sun a day |
| Water | Low; drought tolerance high, waterlogging tolerance none |
| Soil pH | 5.5–7 |
| Cold hardiness | About -34 °C (-29 °F) once established (roughly USDA zone 4) |
| Heat stress | Likely above about 38 °C (100 °F) |
| Flowering | from about June for 6–9 weeks (northern hemisphere; later in cold climates, earlier in warm ones) |
| Wind tolerance | Moderate |
| Pollinator value | High |
| Edible | Not grown as food |
| Native to | Eastern and central North America |
| Common in gardens of | 🇺🇸 United States |
Is Butterfly weed toxic?
- People: moderately toxic
- Cats: moderately toxic
- Dogs: moderately toxic
- Parts: sap, leaves, all parts
Latex contains cardiac glycosides (lower levels than other milkweeds) that can cause vomiting and heart effects; sap irritates skin and eyes.
If a child or pet may have eaten part of a plant, call a poison centre or vet straight away.
Companion planting: what to grow with Butterfly weed
No well-documented helpful pairing. Group it with plants that like full sun and low water.
See Butterfly weed in a botanical garden
It grows in these sample gardens, which you can walk through in 3D:
- Brooklyn Botanic Garden (5 plants)
- Missouri Botanical Garden (10 plants)
- Longwood Gardens (10 plants)
- Denver Botanic Gardens (8 plants)
- New York Botanical Garden (8 plants)
Questions about Butterfly weed
- How far apart should I plant Butterfly weed?
- About 50 cm (20 in) apart, centre to centre. A mature plant spreads 40–60 cm (16–24 in).
- Does Butterfly weed need full sun?
- Full sun: at least 6 hours of direct sun a day.
- How much water does Butterfly weed need?
- Low water. Drought tolerance is high and waterlogging tolerance none.
- How cold-hardy is Butterfly weed?
- It tolerates about -34 °C (-29 °F) once established, roughly USDA zone 4.
- When does Butterfly weed flower?
- From about June for 6–9 weeks (northern hemisphere; later in cold climates, earlier in warm ones).
- Is Butterfly weed poisonous to cats and dogs?
- For cats it is moderately toxic; for dogs moderately toxic; for people moderately toxic. Latex contains cardiac glycosides (lower levels than other milkweeds) that can cause vomiting and heart effects; sap irritates skin and eyes.
- What grows well with Butterfly weed?
- There is no well-documented companion pairing for Butterfly weed. Group it with plants that like the same sun (full sun) and water (low).
Sources and evidence
Evidence grade B (B: extension service or peer-reviewed).
- Missouri Botanical Garden Plant Finder, Missouri Botanical Garden
- Extension Gardener Plant Toolbox, NC State Extension
- ASPCA Toxic and Non-Toxic Plant List, ASPCA
- USDA PLANTS Database, USDA NRCS
Notes and assumptions
- Typical garden-form values; cultivars and local conditions differ.
- Deep taproot resents transplanting; shoots emerge late in spring. Host plant for monarch caterpillars.
Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.
Related plants
- Oleander Nerium oleander
- Frangipani (plumeria) Plumeria rubra
- Madagascar periwinkle Catharanthus roseus
- Star jasmine Trachelospermum jasminoides
- Mandevilla Mandevilla sanderi
- Lesser periwinkle Vinca minor
- Jelutong Dyera costulata
- Madagascar palm Pachypodium lamerei