Douglas Fir: Yellow-green mottle syndrome
categories: Conifers Douglas Fir Douglas Fir Diseases Ornamentals
last review date: 2025-08-15 12:32
Photo by: G.A. Chastanger
Biology
- The cause of yellow-green mottle syndrome is unknown but may be genetic.
- Needles of all ages are affected by yellow-green mottle syndrome. Yellow-green blotches may be small or may cover the entire needle, but the midrib is never affected.
- Mildly affected needles have small or large blotches on only one side of the midrib.
- Severely mottled needles are entirely yellow with a dull green midrib.
- Affected needles usually fall off the trees, sometimes causing severe defoliation.
- Trees sometimes grow out of the syndrome in two or three years.
Management Options
Use Integrated Pest Management (IPM) for successful plant problem management.
Non-chemical Management
Select non-chemical management options as your first choice!
- Give affected trees a chance to outgrow the mottling.
- Remove and destroy trees that are affected every year.
Chemical Management
IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.
- None recommended
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Evidence of noncompliance may be reported through your local Extension office.