WSU Extension

Hortsense

Viburnum : Leaf spot
(revision date: 10/11/2016)


Biology
Various fungi cause leaf spot symptoms on viburnum. The spots are typically necrotic brown spots of varying sizes. At least one bacterial leaf spot is also common.
Management Options

Non-Chemical Management
  • Plant in full sun.
  • Space plants and prune to provide good air circulation.
  • Remove and destroy infected leaves and shoots.
  • Rake and destroy fallen leaves.
  • Leaf spot diseases should be accurately diagnosed before further action is taken. Consult your county Extension agent or WSU Master Gardeners for assistance.
Select non-chemical management options as your first choice!

Chemical Management

Fungicides may be applied to protect new growth or at first sign of disease. Homeowners should not make foliar applications to trees over 10 ft tall. Consult a commercial pesticide applicator for treatment of trees and shrubs over 10 ft. tall.

Listed below are examples of pesticides that are legal in Washington. Always read and follow all label directions.
  • Bonide Copper Fungicide Spray or Dust RTU [Organic]
    Active ingredient: basic copper sulfate  |  EPA reg no: 4-58
  • Bonide Fung-onil Multi-Purpose Fungicide Conc
    Active ingredient: chlorothalonil  |  EPA reg no: 60063-9-4
  • Bonide Liquid Copper Fungicide Conc/Organic Gardening
    Active ingredient: copper octanoate  |  EPA reg no: 67702-2-4
  • GardenTech Daconil Fungicide Conc
    Active ingredient: chlorothalonil  |  EPA reg no: 67572-82-71004
  • Monterey Liqui-Cop Copper Fungicidal Garden Spray
    Active ingredient: copper-ammonia complex  |  EPA reg no: 54705-7
  • Ortho Max Garden Disease Control Conc
    Active ingredient: chlorothalonil  |  EPA reg no: 239-2522
  • This list may not include all products registered for this use.
Images
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Caption: Viburnum leaf spot
Photo by: J.R. Glass