Water Easter lilies in their pots while they are still blooming regularly. An Easter lily's soil should always be moist, and never let the lily wilt.
Clip the dead flowers off the Easter lily after it has stopped blooming, and place it in a sunny window until conditions are right for it to be planted outside.
Dig a hole in a garden location that receives full sun. Loosen the soil in the hole.
Remove the Easter lily from the pot and work through the soil by hand to gently separate the roots and bulb from the soil.
Place the bulb, root side down, into the hole and fill it with the soil you removed.
Water the bulb well and mulch the top with wood shavings, bark or hay.
Clip the remainder of the plant off the bulb if it has not yet died.
Mulch the plant with at least 4 inches of straw to encourage it to survive the winter. The Easter lily is not reliably hardy, however, so you can dig it up in the fall and store it through the winter in a cool but frost free location to replant in the spring.