Answer: Don't move your bulbs until the foliage dies down on its own at the end of the season. Moving them while they're in bloom or while they still have foliage can halt the process of carbohydrate storage into the bulb (which will produce next year's floral display). I agree, trying to remember which is which can be difficult. The best approach is to write the flower color on a tag and wire the tag loosely onto the stem of the plant. The tag will remain throughout the growing season and as soon as the foliage begins to yellow and wither away, you can dig the bulb, replant, then remove the faded foliage.
Best wishes with your lilies!
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