Tree diseases and pests - Woodland Trust

Tree pests and diseases

Trees and woods are crucial. They provide homes for wildlife, clean air and water, food and fuel.

But they're under threat.

60 million trees have been taken by Dutch Elm disease

We will lose at least 80% of ash trees from our landscape in the coming decades

At least 20 introduced pests and diseases are attacking our native trees, six have reached epidemic levels. And at least 11 more diseases are nearing our borders.

These are the main pests and diseases affecting the UK's native trees

Acute oak decline

Acute oak decline is thought to have been affecting our native oak species for around 20-30 years.

Ash dieback

Ash dieback, also known as Chalara dieback of ash, is a serious disease that is killing ash across Europe. Ash is a very important tree in the UK both...

Asian longhorn beetle

Originally from China, this beetle poses a serious threat to a wide range of our native broadleaved trees.

Emerald ash borer

Not yet present in the UK, this wood-boring beetle, native to Asia, has been found in Russia and North America, where it probably arrived in imported ...

Horse chestnut canker

This disease was first reported in the UK in the 1970s but was relatively uncommon until around five years ago.

Horse chestnut leaf miner

In the UK, this was first found in London in 2002. While it does not affect tree health, it does afflict the appearance of horse chestnut trees, and c...

Massaria disease (Photo: Wikimedia Commons)

Massaria disease of plane trees

Plane trees are common in parks and other amenity planting, and are a particular feature in London.

Oak processionary moth

This non-native moth has been found in London and Berkshire. It causes a risk to human health as well as seriously damaging trees.

Phytophthora austrocedri

Phytophthora austrocedri is a damaging plant pathogen that was first seen in the UK in 2011.

Trees with Phytopthora ramorum (Photo: WTML)

Phytophthora ramorum

Phytophthora ramorum is a fungus-like pathogen first discovered in the UK on a viburnum plant in Sussex in 2002.

Red band needle blight

Also known as Dothistroma needle blight, this disease affects conifers, most commonly pine, with Corsican, lodgepole and our native Scots pine all aff...

Sweet chestnut blight

Chestnut blight has now been confirmed in areas of England on sweet chestnut trees. It was first discovered in in 2011, then again in early 2017 at ni...