Once the seed are of species bananas (basjoo, itinerans, balbisiana, acuminata, laterita etc..) and were collected off fully developed ripe fruit; you'd likely have no problems germinating.
I soak dry seed for 1 week in 1 inch of water (frequent water changes) then sow in light soil and cover with 1/4 inch clean fine compost.
You can't be impatient. In the wild, bananas wait for treefalls and monsoons to trigger germination... they sometimes wait until they are "sure" nature isn't playing a trick on them (premature rains that sputter and fail, for example).
Some species (e.g balbisiana) start to push up coleoptiles within a month... other germinate sporadically after months.
Water generously, keep soil warm (85deg F is nice) and let some light shine on the tray of set seeds.
Be patient.
Keep conditions clean; don't over-water after germination - bacteria and fungi are lurking... and can make mush of your seedlings...
I like to prick out seedlings and transplant early - as early as the coleoptile stage. I use a spoon as a dibber so I can get the whole infant root system without breakage (a broken root or mangled leaf serves as an entry point for pathogens).
Believe it or not...I don't use fungicides etc... and my nursery operations are totally organic... but it works!
The hard part will be the first overwintering (caveat - I garden in the Tropics; so I'm not an expert at overwintering bananas)... because the young plant's corm system will be not as developed or as robust as one obtained from a sucker or pup planted out at the same time as a seedling.
Well, that's all!
shannon
shannon.di.corse@gmail.com