Question: Some of my bulbs were disappointing this spring. They produced flower stalks, but the flowers themselves either never opened or were misshapen. I examined some of the buds and found that they were brown and dry inside. What can I do to get better results next spring?
Answer: What you have observed is flower "blasting," in which blossoms abort or emerge deformed. It can be caused by a number of conditions, including improper storage of the bulbs, late planting, inadequate or excessive moisture, sudden temperature changes, or viruses.
Storing bulbs at high temperatures often leads to flower failure. To prevent this, you should try to plant newly purchased bulbs shortly after they arrive in the fall. Storing bulbs in the refrigerator will not necessarily prevent this problem, since ethylene gas generated by fruits in a refrigerator can also cause the flowers to blast.
Late planting also leads to flower blasting because the bulbs do not have time to develop a sufficient root system before they bloom. This is a common cause for failure in tulips, daffodils, crocuses, and Dutch irises.
In daffodils, bud blast is most common in late-blooming and double-flowered cultivars.
It has been speculated that late freezes, inadequate moisture, and wet autumns are responsible, though studies involving irrigation, mulching, and shading have not eliminated the problem. There are blast-resistant double-flowered daffodils such as ‘Meeting’, ‘Sir Winston Churchill’, and ‘Tahiti’. In addition, ‘Baby Moon’, ‘Grace Note’, ‘Geranium’, and most of the poeticus varieties are late-blooming daffodils that are also blast resistant, according to the American Daffodil Society (www.daffodilusa.org).
Finally, viruses can also cause flower distortion and a characteristic streaking or "breaking" of the normal color. With virus infection, the leaves also typically exhibit streaking or yellowed areas. Virus-infected plants must be lifted and destroyed immediately. However, virus is highly unlikely to be your problem. Thanks to careful control in bulb-growing regions, you can assume that the spring-flowering bulbs you purchase are virus free.