The best time to plant daffodils is in fall, as the bulbs are dormant but still have enough time before winter to develop root systems. If you must move daffodil bulbs soon after they flower or from a potted arrangement and into the garden in spring, you should try to wait until the foliage has dried and died before doing so. In those cases where you have no choice but to move daffodils that still have green, wet foliage, doing so with as much care as possible for the existing foliage helps ensure the bulbs survive the process.
Remove the flower stem if it is still in place. Cut it off at the base with a clean pair of shears. This allows the bulb to focus its energy on its remaining leaves and in setting new roots instead of on flower or seed production.
Prepare the garden bed for planting. Remove any weeds or old plant matter from the bed. Lay a 2 inch layer of compost over a full-sun bed, then till it in to the top 6 to 8 inches of soil.
Loosen the soil between the daffodil bulbs with a small spading fork, taking care not to damage any of the bulbs. Slide a trowel under the bulbs, and lift them from the soil. Leave the foliage in place.
Plant the daffodil bulbs so that the bottom of the bulb sits 6 to 8 inches beneath the soil surface. Keep the leaves as upright as possible when refilling the planting hole, but it is fine if some of the green foliage is buried at replanting. Space the bulbs 4 to 6 inches apart in clusters.
Apply 2 lbs. of 5-10-10 analysis fertilizer to every 100 square feet of daffodil bed. Apply the fertilizer to the soil between the plants, as fertilizer on the foliage can cause burning or damage.
Water thoroughly immediately after planting and fertilizing so the nutrients in the fertilizer leach down to the root zone. Water until the top 6 inches of soil feels moist, then cover the daffodil bed with a 2-inch layer of mulch to help preserve the moisture between waterings.