Its trademark yellow flowers keep on coming, one after another, on a twining, evergreen climber that runs up 6.5 to 10 feet of trellis or arbour. Black-eyed Susan vine (Thunbergia alata) is grown for that long, generous display, and asks little in return: sun without scorch, free-draining soil, and shelter from frost, which it cannot take.
| Name | Thunbergia alata |
|---|---|
| Family | Acanthaceae |
| Type | climber |
| Height | 6.5 to 10 feet (2 to 3 meters) |
| Exposure | sunny, but not scorching |
| Soil | well-draining |
| Foliage | evergreen |
| Blooming | late spring through mid-autumn |
This stunning climber boasts truly unique flowers. From planting to pruning, care is particularly easy for such a prolific bloomer.
Plant your black-eyed Susan preferably in spring, especially in areas with cold and/or damp winters.
While this vine is perennial, it’s often grown as an annual due to its sensitivity to frost.
Every job this climber asks for falls at a particular moment of the year. Here is the whole season in one glance, from planting to the last tidy-up.
| Task | When | What it involves |
|---|---|---|
| Planting | Early to mid-spring | Set out in well-draining soil, in a spot sheltered from the dominant winds |
| Watering | Whenever it is hot | The only regular care the plant really needs |
| Training | Through the growing season | Guide the stems onto their support as they lengthen |
| Removing spent flowers and stems | Late spring to mid-autumn, as needed | Snip off wilted stems to keep the display going |
| Light trim at the base | Late summer | Trim back the spreading base so the plant returns with more vigour |
| Shaping and thinning | Mid-autumn or late winter | Reduce or thin out the branches to reshape the vine |
Keep to this rhythm and the flowers do the rest of the work themselves.
In August, when your Thunbergia starts spreading around its base, give it a light trim. It’ll come back with more vigor!
Want to shape or thin out the branches? Best prune in fall or late winter.
Thunbergia, also lovingly referred to as the “Black-eyed Susan vine,” and by some as “Susan’s Eye” or “Zanzibar’s Smile,” blooms beautifully from spring to fall.
Perfect for lighting up your day! What’s so striking about these flowers? They keep on coming and dazzle with their trademark yellow hue.
A good way to ensure proper drainage is to set your arbor up on a raised garden bed.
