Thunbergia Black-Eyed Susan Vine

Thunbergia Black-Eyed Susan Vine — variety description

Thunbergia Black-Eyed Susan Vine (Thunbergia alata) is an annual flower of the Acanthaceae family. The twining stems will reach 6-8 cm and are covered with triangular leaves that have winged stalks and are evergreen for almost the whole year.

It comes from South Africa and, although similar to its tropical African relative, the orange clock vine, this plant is easily recognised by the dark-centred eye of the flower and the winged leaf stalks.

Thunbergia ("black-eyed Susan") is a climbing flower with orange or yellow blooms and a dark centre, for balconies and fences.

Key features

• Measured germination rate of the batch: 80%
• Seeds per packet: 9–13 pcs (0.3 g)
• Seed origin: Poland
• Sowing: February – April; seedlings
• Flowering: April and May
• Position: sunny spot

When to sow Thunbergia Black-Eyed Susan Vine

Thunbergia Black-Eyed Susan Vine seeds are sown in February – April. The plants flower in April and May. The months are a guide for a temperate climate — in warmer areas sow 1–2 weeks earlier, in cooler or upland areas, later.

How to sow and grow Thunbergia Black-Eyed Susan Vine

• Sowing method: seedlings
• Depth: 0.5–1 cm
• Spacing: 30 cm, next to a support
• Germination: 10–20 days at 20–25 °C
• Position: sunny spot

The seeds germinate easily in a moist mixture of fine, humus-rich soil with a little sand. A sheet of glass on top helps keep the soil moist while letting a little air circulate. Mature plants may have seedlings underneath, ready for transplanting. Use a light, humus-rich soil with good drainage and add a little superphosphate. Water the plant frequently at first, then moderately throughout the year, but especially in summer. Add compost at planting time and again 2 or 3 times during the summer as a mulch. Give an occasional feed with a flowering-plant fertiliser or a general fertiliser (ratio 2:3:2). Black-eyed Susan grows quickly and starts flowering at an early age. It can be pruned if it gets too large, but generally it behaves well. Light pruning in spring will encourage flowering. If frost is a problem, cut the plant back hard and it will probably shoot again.

Sow in February–March; plant outside after the last frosts.

Flowering and uses

Flowers from June until the frosts.

Frequently asked questions

When should Thunbergia Black-Eyed Susan Vine be sown?

The recommended sowing months are February – April. Sowing method: seedlings.

How many seeds are in the packet?

The packet contains 9–13 seeds, pack size 0.3 g.

What is the germination rate of the seeds?

The measured germination rate of this batch is 80%. The test was carried out under controlled laboratory conditions; in the field, emergence depends on soil, temperature and moisture.