What pests attack walnut?

Codling moth, San José scale, Scale insects, Leaf rollers

Walnut pests and diseases: how to recognise them

Q: Which walnut problems need quick action?

Honey fungus: Black or brown root-like cords ("bootlaces") on the roots and in the soil, mostly in the top 15 cm.

Juglans regia

The pests, diseases and disorders recorded for walnut in our library, each with a photo and its first symptom. Every page has the full list of symptoms, organic and chemical treatment and prevention.

At a glance

Problems in total	5
Pests	4
Diseases	1
Need quick action	1

How to grow walnut · All pests and diseases

Pests

Codling mothA hole in the side or the eye end of the fruit, often plugged with reddish-brown crumbly droppings.Also called: codlin mothPhoto: Simon Winkley & Ken Walker, Museum Victoria, CC BY 3.0 au, Wikimedia Commons
San José scaleGumming on the bark and dying twigs and branches.Photo: Zihao Wang, CC BY 4.0, Wikimedia Commons
Scale insectsSome species lay eggs under white, waxy, cotton-like fibres on stems or leaf undersides.Photo: BARAKAT2011, CC BY-SA 3.0, Wikimedia Commons
Leaf rollersBronze scars with a rough, net-like surface on the fruit skin.Also called: tortrix moths, leafroller mothsPhoto: Patrick Clement, CC BY 2.0, Wikimedia Commons

Diseases

Honey fungusBlack or brown root-like cords ("bootlaces") on the roots and in the soil, mostly in the top 15 cm.Photo: Stu's Images, CC BY-SA 3.0, Wikimedia Commons

Which walnut problems need quick action?

These spread or do lasting harm fast; check the plants and start treatment the day you see them.

Honey fungus: Clumps of honey-coloured mushrooms around stumps or over dead roots in late summer and autumn — not every year, and plants may die before any appear.

Plants with many of the same problems

Which plants each problem affects: sources

The links between these problems and the plant were checked against these pages.