I have now tried several times to grow this species from seed
Last year I sowed seeds and grew 2 plants of the species with blue flowers ...unfortunately no flowers - overwintering did not work out .
This year I ordered new seeds (blue and white flowers)
The blue-flowered ones germinated quite well ( 4 seedlings ) of the white-flowered seeds I only got one seedling to germinate ... the plants all grew well ( in the greenhouse ) but the flowers were poor ... maybe the seeds were already old ?
At least the white-flowered plant flowered ...the blue-flowered ones: nothing ( although the plants were much bigger )
I pollinated the flowers and they even set some fruit ...
I disposed of the blue-flowered plants as they didn't survive the winter last year ... I brought the white-flowered plant indoors so that the fruits could ripen ... I was able to harvest some seeds in the last few weeks.
If you are interested I can give you some of the seeds
Hans