Filbert Blight - Anisogramma anomala

Filbert Blight is one of the most serious diseases affecting Hazelnut trees – especially the European varieties. Caused by the fungus Anisogramma anomala, it can go unnoticed for over a year before symptoms appear.

It starts with sunken, oval-shaped cankers on branches – usually at the base of new shoots. Look closely and you’ll see small rows of black dots (the fungus’ fruiting bodies) embedded in the bark. Eventually the shoot above the canopy will wilt and die back. Left unchecked, entire limbs or trees can be lost.

Spores are released in the spring during wet weather and infect young shoots. The tricky part is that the infection remains hidden for 12-18 months. Here’s how you can manage it:

·         Prune out infected branches in the late summer to winter when the fungus isn’t actively releasing spores.

·         Always cut well below the canker – at least 3 ft.

·         Burn or dispose of infected wood off-site.

·         Apply fungicides early in the growing season.

·         Plant resistant Hazelnut varieties when possible.

Filbert Blight doesn’t have to spell the end of your trees – but it does require attention and care. If you’re unsure how to spot it or where to prune, consult with an Arborist. We’re here to help our trees stay healthy, productive, and blight free.