Could you please let us know if you're talking about one of the lilies known as 'Turk's cap'?

If you are - then you can probably leave them undivided and feed them with a generous serve of compost, perhaps with a side dressing of dried steer manure or sheep manure pellets. Old leaf mould is also good.

Yes - maybe I should have posted it somewhere else???? It gets to be about 40" tall with several blooms on the top