I think "it depends".
Are they growing in the ground or in containers?
Is the soil or soilless mix rich, highly organic and fertile, or mostly sand, bark, or Perlite?
Are they in their growing season or dormant where you live?
What kind of lily are they? I see 9 "Divisions" and many genuses (genera?).
Are they already dark green and growing well? Or are they yellowing and hungry when they should be growing rapidly?
You might look here, at the "plant parent page" and see if it helpss to narrow down yourquestion:
Lilies (Lilium)
Someone who knows more than I do about lilies and peonies would know what parts of their life cycles are heavy feeders and which are best left lean.
"Starve a cold but stuff a fever" has analogies in the plant world.
For example, and these are just guesses:
- they might want more fertilizer including nitrogen when fairly young
- but no fertilizer as tiny seedlings and while getting ready for cold weather
- they might want extra phosphorus but less nitrogen right before blooming.
