Over time, this can cause wilting, stem dieback, and in severe cases, shrub death. To date, there is no effective treatment for forsythiagalls. ForsythiaGallTreatment. Since the phomopsis gall fungus doesn't overwinter in debris like many fungi, instead hanging out in the galls as an active infection, there's a risk of transmitting... The treatment for Forsythiagall is consistent across Extension publications though. If they do have galls present, you should remove these branches as soon as possible. Forsythia stem galls may be caused by a Phomopsis fungus or, as Oregon State University Pacific Northwest Nursery IPM asserts, by the bacteria Pseudomonos savastanoi.Treatment. Take care of your forsythia for better bloom! Learn how to plant, grow, and care for forsythia bushes—including tips on when to prune. ForsythiaGallTreatmentTreatinggalls on forsythia isn't possible; the only thing you can do once they arise is to remove them cleanly. The galls on forsythia, viburnum, highbush blueberry, American elm, hickory, maple, oak, and privet are believed to be caused by a fungus, Phomopsis sp. Cause The OSU Plant Clinic has isolated the bacterium Pseudomonas savastanoi from galledforsythia tissue from several locations. This bacterium is also involved with... Forsythia intermedia Lynwood Variety. The classic Forsythia which is less likely to suffer from gall compared to others. Masses of bright yellow flowers are almost guaranteed every year. Unsightly galls developing on forsythia not only detract from the appearance of the trees but weaken and eventually kill affected branches. Symptoms and Signs.
