Fasciation affects many plants, including alyssum, aster,
carnation, chrysanthemum, geranium, impatiens, Marguerite
daisy, nasturtium, petunia, and primrose. Fasciation is an
abnormal flattening of stems, often appearing as if several
adjoining stems have fused. Fasciated
plants have short, swollen clumps of distorted shoots. Leaves
growing from distorted stems are abnormally abundant and
undersized. Distortion often develops at the plant
base, and crowns may appear galled. Sometimes only
new terminal growth is affected. The cause of most
fasciations is not understood. Some may be genetic
and others may be caused by bacterial or viral infections. Fasciation
bacteria survive on infected plants and debris. They
spread in water and through wounds.
Control bacterial fasciation primarily through good sanitation and use of pathogen-free plants. Avoid injuring the base of plants, especially when plants are wet. Keep the base of plants dry. To control fasciation to all potential causes, do not propagate or graft symptomatic plants. Remove and dispose of infected plants, or prune and dispose of distorted tissue and do not propagate from those plants.
Snapdragon stem and blossoms damaged by fasciation