Posted: 06/11/2014 at 16:18
Fatsia japonica seeds need to be fresh to germinate. They need 20C for a few weeks and light, so surface sow. I find a large batch of seed results in only a few seed...mainly as I tend to forget my own advice and leave the seeds lying for weeks or longer. They grow quickly.
They are hardy outside in most of the UK as long as they have drainage and a sheltered spot. They do better on the ground than in pots and they get bigger faster. Vine weevil grubs can really go for Fatsia's thick roots in pots. Not fun when you see a dropping plant give it a tug and the whole plant comes out sans roots.
Flowers appear when they like and on any sized plant. I have seen them on quite small plants, perhaps a sign of stress as I would expect them not to flower until 3+ years old.