If you look closely you can see black spots on the cotyledon and early leaves of the Shoo Flower plant. Thats how I always know what it is , even when only a cm high. My beloved Echium seedlings however have spots on their first but not cotyledon leaves and hairy leaves, very Jacob and Esau.
I have had a Shoo Flower plant in my various gardens since 1981 when I was given the first one to keep in the greenhouse because it kept white fly at bay , hence its silly name. The seed capsules (like Cape gooseberries) are very easy to store and filled with hundreds of seeds, like other members of the Potato family. So back-end I just fling the seeds all over the garden and wait for the spring excitement of seeing where they come up.
Whether it does repel white flies I don't really know ,as I always seem to get white fly eventually , especially here in the Frozen North as ventilation of the greenhouse is a delicate business. It might be 29 degrees in Brighton but it will be 21degrees in Filey. When the sun is out and the greenhouse reaches 29 degrees I am probably in Beverley and even forgot to open the door and have to do rescues when I get home.
I love this plant. Mine are all about 4'high now so I only have a few.
AsideWe have a tiny garden and I have half a dozen 'Only the lonely ' Tobacco Plants, already each is 2'across. I have dozens of Echium pininana x wildpretii plants all growing inches over night it seems , tall and sturdy . I want to get them through the winter, well at least one of them so that I can brag about it on my Facebook Site. I have 6 different varieties of Echium at the moment, . Only one is hardy, my E. lusitanicum spp polycaulon.
Back to my Nicandra , My best Shoo Plant. If I am very careful and manage to dry it properly it will be tall enough and branched enough and interesting enough and light enough to be the Christmas Tree substitute in the downstairs sitting room .