Butterfly bush vs Summersweet
Butterfly bush feeds butterflies, but its leaves feed no North American caterpillar, and its seed escapes; it is listed as invasive or as a noxious weed in parts of the United States (sterile varieties such as 'Blue Chip' are the exception). Summersweet is a native shrub that flowers at the same time, in fragrant white or pink spikes, and is busy with butterflies and bees.
 Butterfly bushBuddleja davidii |  SummersweetClethra alnifolia | |
|---|---|---|
| Size | 8 ft tall, 6½ ft wide | 6½ ft tall, 5 ft wide |
| Plant | 6 ft apart | 4 ft apart |
| Zones | 5 to 9 | 3 to 9 |
| Light | Full sun | Full sun to part shade |
| Soil | Well-drained, average fertility | Evenly moist, average fertility |
| Flowers | Early July to early October; purple, pink, white | Mid July to mid August; white, pink |
| Leaves | Medium, deciduous | Medium, deciduous |
| Job in a bed | Anchor | Anchor |
| Pets | No toxicity recorded | No toxicity recorded |
| Deer | Resistant | Resistant |
| Native | No | Yes |
| Spread | Invasive in places | Moderate risk |
Rows where they differ are marked. Flowering times are for zone 5.
Which to choose
- Choose butterfly bush for dry summers and a longer show (14 weeks of flower against 6).
- Choose summersweet for more shade, colder gardens (to zone 3), moist soil, a native garden, a plant that stays put (the other is invasive in places) and more wildlife.
Read more: all about butterfly bush, and all about summersweet, each with a bed the planner designed around it.