Dame's rocket vs phlox
Dame's rocket is the plant that fills roadsides and woodland edges with lilac, purple and white in late spring, and it is often taken for wild phlox. Count the petals: dame's rocket, a mustard, has four; phlox has five. Dame's rocket is a European biennial that has escaped across North America and is banned from sale in some states. Garden phlox is a native perennial that flowers later, in high summer, and stays where it is planted.
 Dame's rocketHesperis matronalis |  Garden phloxPhlox paniculata | |
|---|---|---|
| Size | 3 ft tall, 18 in wide | 3½ ft tall, 24 in wide |
| Plant | 16 in apart | 24 in apart |
| Zones | 3 to 8 | 4 to 8 |
| Light | Full sun to part shade | Full sun to part sun |
| Soil | Well-drained, average fertility | Evenly moist, rich fertility |
| Flowers | Mid May to late June; purple, lavender, white | Mid July to early September; pink, white, purple |
| Leaves | Medium, herbaceous | Medium, herbaceous |
| Job in a bed | Drift | Drift |
| Pets | No toxicity recorded | No toxicity recorded |
| Deer | Resistant | Not listed as resistant |
| Native | No | Yes |
| Spread | Invasive in places | Low risk |
Rows where they differ are marked. Flowering times are for zone 5.
Which to choose
- Choose dame's rocket for more shade, colder gardens (to zone 3), dry summers and deer country.
- Choose garden phlox for moist soil, a native garden, a plant that stays put (the other is invasive in places) and more wildlife.
Read more: all about dame's rocket, and all about garden phlox, each with a bed the planner designed around it.