Daffodils, also known as narcissus or jonquils, grow from underground root stems called bulbs and are one of the easiest spring flowers to cultivate. Depending on the variety, they grow well in USDA plant hardiness zones 3 to 9. Fortunately, with just a little bit of care -- and sometimes without any care at all -- they will reward you with some of the first signs of spring: large, beautiful, trumpet-shaped blooms.
Provide daffodils with soil that drains water well. If your daffodils sit in water a lot, and they are not thriving, then you need to dig them up and either move them to a better location or build a raised garden. You can also till the area about 12 inches deep and mix in 4 to 6 inches of coarse sand, compost or another organic matter.
Fertilise daffodils lightly in the spring when you first see new growth. Sprinkle a handful of bulb fertiliser around the base of your plants. Do not get any fertiliser on the foliage. If you do, wash it off with your hose. At planting time, however, mix in 0.907 to 1.36kg. of fertiliser with an N:P:K ratio of 1:4:4 or 1:3:3 for every 100 square feet.
Water daffodils in the spring to keep the soil slightly moist. Other times of the year, you don't usually need to water daffodils.
Cover the planting bed with 2 to 3 inches of mulch, such as wood chips or pine needles, to help the soil retain moisture and to keep the soil temperature consistent.
Avoid cutting off the foliage while it is still green, even after it's done blooming. The foliage is still active, soaking in the sun and converting it into energy. This will help next year's plants thrive.
Tie the green foliage into bundles if you consider the daffodil bed unsightly after blooming. This step is optional, but will allow room for you to plant flowering annuals around your daffodil planting bed to liven the area with some colour.
Prune back daffodils when the leaves finally turn yellow, usually after the first frost. You can cut them all the way back to the ground now. The daffodils will return in the spring.
Divide bulbs every five to 10 years in the fall, when the daffodils stop blooming as much and look overcrowded. Chances are, there are just too many bulbs now competing for the same water and nutrients. Dig the bulbs up, dry them on trays for a couple of days and separate the bulbs with your hands. Replant the bulbs 6 to 12 inches apart and 6 inches below the soil. Plant smaller bulbs near the back of the planting bed or in between larger bulbs. They may not bloom for the first year or two.