Q.after care of lilies
When do you cut back the lilies after they bloom, and how deep do you plant the new bulbs?

It is best to leave the plant alone while leaves are rebuilding the bulb. Flowering is hard work for a plant! When the leaves start to fade or turn yellow, it is OK to dig the bulbs. You will notice there are new "bulblets" that you can allow to remain with the main bulb for a larger plant or separate and replant to increase numbers. It will need at least one whole season on its own to reach blooming size. More info here: https://www.gardeningknowhow.com/ornamental/bulbs/lily/propagating-an-asiatic-lily-plant.htm