Thunbergia alata

The Thunbergia alata, or Black-eyed Susan, is a climbing plant cultivated as an annual for its cheerful yellow flowers with black centres that bloom abundantly throughout the summer. With rapid growth, a small green plug plant will reach 2m (7ft) in just one season. Its stems, covered in lush foliage, cling to trellises and fences, allowing for the quick creation of large and decorative pots or astonishing hanging baskets that can be kept in the conservatory. The Black-eyed Susan enjoys heat and sun, as well as fertile, moist, and well-drained soil.

The Thunbergia alata, is a fast-growing perennial and voluble climbing plant that can only tolerate light frosts. It is a species native to tropical regions of East Africa, usually grown as an annual in our climates. The Black-eyed Susan reaches a height of approximately 2m (7ft) in just a few months, up to 3m (10ft) in open ground. Its slender, quadrangular, hairy, and purplish stems wrap around their support. They are adorned with lush, dark green foliage, consisting of evergreen (except in frost) hairy leaves with serrated edges, heart or arrow-shaped, measuring 4 to 8cm (2 to 3in) long. They are attached to the stems by an axillary petiole. Flowering occurs from June-July to October. The 3-4cm (1-2in) flowers, surrounded by a hairy calyx, are borne on peduncles in the axils of the leaves. The corolla is tubular at the base and extends into five flared lobes. The flowers are an intense and pure yellow, very warm in colour. In the centre of this flower shines a beautiful and characteristic dark purplish eye, whose role is to attract pollinating insects.

The Black-eyed Susan is suitable for both container and open ground cultivation, in sunny locations. A voluble climber, but lightweight, it pairs well with a perennial climber such as Clematis heracleifolia 'Côte d'Azur' and can also be used as ground cover. You can combine it with summer-flowering bulbs, such as Crocosmias and gladioli: it will twist around the leaves and bloom in the most unlikely places, adding whimsy to somewhat rigid borders. It will also have a great impact in a large container or hanging basket.

Green plug plants measuring 4 to 8cm (2 to 3in), in packs of 5 small plugs, 3.6cm (1in) in diameter and 4cm (2in) in height. Our plants are at least eight weeks old and strong enough to be planted in open ground.

Note: Please be aware that our young plug plants are professional products intended for experienced gardeners: upon receipt, repot and store them in sheltered areas (conservatory, greenhouse, cold frame etc) at a temperature above 14°C (57.2°F) for a few weeks before planting them outdoors once the risk of frost has passed.