Filbert: Eastern filbert blight

• Categories: Filbert Filbert Diseases Tree Fruits
• Last review date: 2026-05-05 01:51

Biology

Eastern filbert blightis a fungal disease found on both cultivated and wild filberts. The disease typically infects via wounds caused by mechanical or insect damage. Buds damaged by the filbert bud mite may be particularly susceptible. Buds, twigs, and stems may be infected.

The disease causes cankers, sometimes girdling and killing branches in summer to early fall. Cankers are typically somewhat sunken and may be surrounded by a ridge of callus tissue. The wood beneath the canker is stained dark brown.

The bark of infected twigs may develop rows of bumps or pustules which split open to reveal white fungal fruiting bodies. The sticky white spores are released during wet weather through winter and early spring.

The ornamental contorted hazelnut (Corylus avellana ‘Contorta’) may also be infected.

Management Options

See "Using Integrated Pest Management (IPM) in the Landscape" for successful problem management techniques.

Non-chemical Management

Select non-chemical management options as your first choice!

• Plant moderately resistant varieties such as ‘Hall’s Giant’, ‘Tonda di Giffoni’, or ‘Willamette’.
• Some varieties used as pollenizers are susceptible to infection, including ‘Butler’ and ‘Daviana’. The cultivars ‘Ennis’ and ‘Tonda Romana’ are also susceptible.
• Prune out and destroy cankered branches. Make pruning cuts at least 3′ below canker.
• Remove severely infected trees.
• Avoid overhead watering during the period spanning bud break through shoot elongation. Spores are spread by rain and splashing water.

Chemical Management

• A total of four (4) applications is recommended to adequately protect trees. Apply starting at budswell to bud break and continue at 2-week intervals to cover an 8-week period.
• Thorough coverage of all branches is essential. Alternate or tank-mix fungicides from different groups with different modes of action.
• The addition of a surfactant, if allowed by the label, will improve disease control.
• 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.

Approved Pesticides

If you choose to use a pesticide, some examples of products that are legal in Washington are listed below. Some products are labeled for just INDOOR or just OUTDOOR use, or may allow both uses. Be sure to choose a product appropriate for your situation. Always read and follow all label directions.

• Hi-Yield Vegetable, Flower, Fruit and Ornamental Fungicide
  Active ingredient: chlorothalonil
  EPA registration number: 60063-16-7401
• Monterey Liqui-Cop Copper Fungicidal Garden Spray
  Active ingredient: copper-ammonia complex
  EPA registration number: 54705-7
• This list may not include all products registered for this use.