Plant dormant bulbs in a sunny area of your yard in fall in loose, well-draining soil. If the bulbs are already planted, but are in a shaded area, then transplant them to the full sun area at this time. Daffodils prefer at least six hours of direct sun each day.
Spread granules of a 5-10-10 fertilizer over the ground after planting. Plan to feed again in late winter to early spring once leaves have appeared above ground and then a second time in spring when the plants actually bloom. Repeat feeding twice every spring.
Water the daffodils with 1 inch of water a week once leaves emerge. Don't provide extra water when rainfall is sufficient. Continue to water weekly through the bloom period and for six weeks after blooming is complete, as the bulb forms and absorbs nutrients to store.
Trim away the dead and dying leaves from the daffodils with hand pruners once they begin to turn yellowish brown about six weeks after blooming. The dying leaves signal the bulb is forming for the following year and the leaves are no longer necessary.
Divide clumps of bulbs every one to two years after the leaves turn to keep them out of competition with one another for water and nutrients as this can stop blooming. Space the divided bulbs 6 inches apart and always in a sunny, well draining area. Wait to water the divided bulbs in fall.