Wikimedia Commons / CC
garden
Wild senna
Overview
A tall native prairie legume that produces showy yellow flower clusters and dramatic dark seed pods, wild senna (Senna hebecarpa) is both an important pollinator plant and a historical medicinal herb. It is a larval host plant for several sulphur butterfly species and fixes nitrogen in the soil. The ornamental seed pods persist through winter, adding structural interest to the dormant garden.
Companion Planting & Soil
Good Companions
Soil pH5.5 — 7
Soil TypeMoist, well-drained soil; adaptable to most conditions
Planting Calendar
When to sow, transplant, and harvest by growing zone.
| Zone | Action | Months | Notes |
|---|---|---|---|
| Cold (1-2) | Transplant | May — Jun | Plant in spring; native legume; host plant for cloudless sulphur butterfly |
| Cold (1-2) | Bloom | Jul — Aug | Yellow flower clusters in midsummer; attractive dark seed pods |
| Cool (3-4) | Transplant | Apr — May | Plant in spring; grows 4-6 feet; nitrogen fixer |
| Cool (3-4) | Bloom | Jun — Aug | Summer bloom; sulphur butterfly caterpillars feed on leaves |
| Moderate (5-7) | Transplant | Mar — Apr | Plant in spring; rattling seed pods add winter interest |
| Moderate (5-7) | Bloom | Jun — Aug | Summer bloom; shrubby habit needs no staking |
| Warm (8-9) | Transplant | Feb — Mar | Plant in late winter/spring; drought tolerant |
| Warm (8-9) | Bloom | May — Jul | Late spring/summer bloom |
| Hot (10+) | Transplant | Nov — Dec | Plant in fall |
| Hot (10+) | Bloom | May — Jul | Summer bloom; heat tolerant |
Uses
Other Uses
- Larval host plant for sulphur butterflies
- Nitrogen-fixing native legume
- Architectural seed pods provide winter interest
- Prairie and meadow restoration species
