Are you referring to Cardiocrinum Giganticum? In which case once the bulb has flowered it dies and you have the bulblets that take 3 - 5 years from forming before they flower. You don't need to do anything to them just leave them where they are and they'll do there own thing.

I don't think they are Cardiocrinum Giganticums as I have some tree lilies and they flower each year and get bigger.

Pot the smaller bulbs up in multipurpose compost keep frost free over winter and when they leaf up next year give them regular feeds. that way they will continue to get bigger and will take 2-4 years before they flower.

Thanks to all of you.
You have confirmed what I thought was correct.
Regards Garth