Thunbergia alata Seeds

Thunbergia alata is an invasive perennial in its country of origin, but an adorable annual climbing plant in temperate climates. It displays flowers from June to October in different colours: warm orange, red, light orange, reddish-orange, white or bright yellow, with or without a small centre of characteristic purple, almost black, which earned it its pretty name of Black-eyed Susan. Its stems, covered with lush foliage, cling to trellises on their own and allow for the quick creation of large and decorative pots that can be kept in the conservatory. It appreciates warmth and sunlight as well as fertile, cool and well-drained soil.

Thunbergia alata is a fast-growing, perennial and voluble climbing plant native to tropical regions of East Africa, which only tolerates very light frosts. It is for these reasons that it is grown as an annual in temperate climates. It reaches a height of 2 m (6 ft 7 in) in a few months. Its stems wrap around their support. They are covered with lush, dark green foliage, composed of evergreen (frost-proof), villous, dentate leaves, shaped like a heart or an arrow. Flowering occurs from June to October, depending on the sowing date. The flowers are borne on a peduncle, in the axil of the leaves, and come in different shades of orange, yellow, red or white. The corolla is tubular at the base and extends into five spreading lobes. At the centre of this flower shines an eye, which is not always black, whose role is to attract pollinating insects.

Black-eyed Susan is suitable for cultivation in both pots and open ground, in sunny locations. A voluble but light climber, it pairs well with a perennial climber, such as a clematis, and can also be used as ground cover. You can combine it with summer-flowering bulbs such as gladioli: it will twist around the leaves and bloom in the most unlikely places, adding whimsy to somewhat rigid flower beds.