Daffodils are among the first of the spring flowers, and grow from bulbs in a riot of blue-gray stems and yellow and white flowers. Gardeners plant daffodil bulbs in fall, in quick-draining, nutritious soil that gives the bulbs good support and food. Although daffodils can grow in shade, they do better in full sun and warm, slightly moist earth. To be truly successful, though, the daffodil bulbs need to be healthy and viable from the start.
Healthy daffodil bulbs are solid and somewhat moist, without any signs of obvious damage or rot. Bulbs that feel soft or have discolorations may be unhealthy and have outside growths, like mold.
Flower bulbs develop different molds during storage. Mold may be blue-green, gray or white, but always affects the bulbs negatively. This parasitic growth attacks the flower bulbs and lives off the growing material inside.
Growing Daffodils with Mold
The effects of growing bulbs with mold depend largely on the type of mold itself. In most cases, daffodil bulbs with mold put forth small, withered and unhealthy blooms. Because mold can overwinter in the ground, it's best to dig up damaged bulbs to store them cleanly and replant them in a different location the next fall.
According to Tulip Test Gardens, flower bulbs mold when they're stored improperly, in areas that are warm or humid and close to fruits or vegetables. If you plan to store daffodil bulbs before you plant them, do so in bags that encourage good circulation, and in a dry, cool location.
Healthy bulbs sink in water, while decayed bulbs float. Always test bulbs for viability before you plant. If you have moldy bulbs, rinse them in a solution of half bleach and half water to kill the mold before attempting to plant them.