Help the development of the site, sharing the article with friends!

Black-eyed Susanne is one of the best-known climbing plants from south-eastern Africa. The pretty flowering plant is quite undemanding and can be easily cultivated by beginners. Due to its easy cultivation and long flowering period, it is popular in private gardens and as a container plant on balconies and terraces. Since it is an annual plant, the process is repeated annually. With the right approach, sowing Thunbergia alata becomes child's play.

Sowing: time

Before you can start sowing Black-eyed Susan, you need to choose the right time. The acanthus plant (bot. Acanthaceae) does not come from Central Europe but from warm Southeast Africa, which makes it impossible to sow outdoors. You must prefer the attractive climbing plant in the house. There are two dates for this very purpose, depending on the availability of a mini greenhouse:

  • Mid to late January with mini greenhouse
  • Beginning of March without a mini greenhouse

The species is one of the plants that must be preferred in the house over a long period of time in the local latitudes. The reason for this is the low temperatures in spring and the risk of late frosts, which would severely affect the young plants. That is why a black-eyed Susanne is kept as an annual in most cases, but inspires with its blooms until autumn. It takes a proud four months until the flowers form, which explains the early sowing.

Notice: Alternatively, you can sow the seeds directly outdoors after the Ice Saints if you can wait much longer for the flowers to flower. In this case, it does not show its flowers until late summer, but keeps them until the beginning of winter.


Black-eyed Susanne needs an optimal location so that the seeds can germinate effectively after sowing. Since the plant is a dark germinator, the seed does not depend on light in any way, which makes it easier to grow in many forms. After preparation, you can place the culture vessels in a dark place, ideally at 20°C. As soon as the first seedlings can be seen, the location must be adjusted somewhat. From this point on, the place at a bright window without direct midday sun is necessary until you plant out the young black-eyed Susanne. Make sure that the seedlings are not draughty, as the species does not tolerate these circumstances.

Cultivation: procedure

Once you've decided on a date, you can start sowing the seeds in planters. The procedure is not complex and can be easily implemented even by beginners, since the black-eyed Susanne is undemanding in terms of the substrate. You need:

  • planters
  • high-quality growing soil
  • sand
  • cling film or mini greenhouse
  • spray bottle

When choosing the planters, you should consider the following points:

  • Material: clay, plastic
  • Diameter: 10 to 12 cm
  • not too high

Since the individual seeds need some space, you should not use pots that are too small. Black-eyed Susan develops an extensive root system, through which she can build up enough strength to grow tall. If you have all the necessary materials and utensils at hand, you can start growing. The procedure succeeds in the following way:

  • Fill pots with potting soil
  • Potting soil up to 2 cm below the edge
  • max. 5 seeds per pot
  • Place seeds on the substrate
  • Maintain spacing between seeds
  • 1 cm sand or substrate layer on the seeds
  • this corresponds to the sowing depth
  • press gently with fingers
  • Cavities are thereby compressed
  • moisten with a spray bottle

But the sowing of the black-eyed Susanne is not over yet. Depending on whether you have a mini greenhouse or not, you have to proceed in different ways. If you have a mini greenhouse, place the seed pots in it. If you don't have one, cover the pots with cling film. The film prevents the seeds from drying out and not germinating due to low humidity. In the next two to three weeks it is now important to keep the soil sufficiently moist. To do this, check the substrate daily for dryness and moisten it as necessary.

Tip: You can either buy seeds for the black-eyed Susanne in stores or collect them from your own specimens that you or your friends have. To do this, leave the withered flowers and ripen into seed pods, which you can then harvest.

Prick out and plant out

The first seedlings should appear after a maximum of three weeks. Don't be surprised if the number of seedlings is low, Black-eyed Suzanne is notorious for germinating very erratically. As soon as the seedlings appear, separate them. A maximum of three seedlings should be used per pot, otherwise there will be a lack of space. Use high-quality uniform soil for this, as the little plants do not yet need as many nutrients. When transplanting, select only the strongest specimens. During the time leading up to after the Ice Saints, you must observe the following points:

  • Use trellis
  • keep soil moistured
  • protect from midday sun
  • pinch at regular intervals
  • give liquid fertilizer after about 8 weeks

From mid-April, the plants are hardened off. This means that you put them on the balcony or terrace when the weather is good so that the little plants can get used to the outside world and become more robust. Planting out or repotting into the final containers is possible after the ice saints. One of the following soils is used in the pot for black-eyed Susanne

  • plant soil
  • geranium soil
  • potting soil

Here too, make sure that the quality is high, as the Thunbergia alata will grow much better this way. In the field there should only be sufficient humus-rich soil. It is also important that the location is protected from the wind, as the climbing plant is quickly caught by the wind.

Tip: There are different climbing aids for Thunbergia alata that you can use to support the plant. Sturdy strings, rose sticks, bamboo sticks or even branches that have to be fixed well in the ground to give the plant enough support are particularly suitable.

Help the development of the site, sharing the article with friends!