Black-eyed Susan vine

Thunbergia alata

East African twining climber with arrow-shaped leaves and continuous five-petalled flowers in orange, yellow, or cream around a dark chocolate central eye. Tender perennial usually grown as a warm-season annual.

Hardiness ratings

Black-eyed Susan vine hardiness across the four zone systems
SystemRatingTemperature rangeHow to read it
USDA hardiness zone Zone 10–11 −1.1 °C to 10 °C Zones where it can be grown as an annual — not a frost-tolerance rating
RHS hardiness rating H2 1 °C to 5 °C Plant needs at least this level of cold tolerance
Canadian plant hardiness zone Zone 9 −1 °C and warmer Zones where it can be grown as an annual — not a frost-tolerance rating
Australian (ANBG) zone Zone 4–7 0 °C and warmer Zones where it can be grown as an annual — not a frost-tolerance rating

As a tender annual, Black-eyed Susan vine doesn't overwinter — the zone range shows where the growing season supports it. See the RHS rating for its actual cold tolerance.

Growing notes

  • Plant in summer containers, against trellises, and as a hanging basket plant — flowers continuously from late spring to first frost
  • Fast growing — reaches 2–3 m in a single warm season
  • Distinct from the perennial Rudbeckia black-eyed Susans — Thunbergia is a tender climber, Rudbeckia is a hardy daisy perennial
  • Frost-tender — perennial only in zone 10 and warmer
  • Not reliably hardy outdoors in Canada — Canadian zone values shown represent the system maximum and do not imply garden cultivation north of the warmest coastal pockets.

Categories

Related plants

Cross-check Black-eyed Susan vine against your zones

Reference

Black-eyed Susan vine on Wikipedia