Butterfly weed vs Swamp milkweed
Both are native milkweeds and host plants for the monarch. Butterfly weed is short and orange and wants sun and dry, sandy soil; it hates being moved. Swamp milkweed is taller, pink, and despite its name grows in ordinary garden soil as well as wet: it is the easier milkweed for a border.
 Butterfly weedAsclepias tuberosa |  Swamp milkweedAsclepias incarnata | |
|---|---|---|
| Size | 24 in tall, 18 in wide | 4 ft tall, 24 in wide |
| Plant | 18 in apart | 24 in apart |
| Zones | 3 to 9 | 3 to 9 |
| Light | Full sun | Full sun to part sun |
| Soil | Dry and sharply drained, lean fertility | Evenly moist, average fertility |
| Flowers | Late June to early August; orange | Early July to early August; pink, white |
| Leaves | Medium, herbaceous | Medium, herbaceous |
| Job in a bed | Drift | Drift |
| Pets | Toxic (moderate) | Toxic (moderate) |
| Deer | Resistant | Resistant |
| Native | Yes | Yes |
| Spread | Low risk | Low risk |
Rows where they differ are marked. Flowering times are for zone 5.
Which to choose
- Choose butterfly weed for dry summers, a smaller space (24 in against 4 ft) and more wildlife.
- Choose swamp milkweed for more shade, moist soil and more height (4 ft against 24 in).
Can they grow together?
Yes: they grow in the same conditions. Beside butterfly weed, swamp milkweed is in flower together for six weeks, from early July; tall enough (4 ft) to stand behind it. They share full sun and zones 3 to 9.
Read more: all about butterfly weed, and all about swamp milkweed, each with a bed the planner designed around it.