Bacterial Canker of Poplar (Xanthomonas populi)

What it affects

All Poplar varieties

Symptoms

Dead branches and twigs throughout the crown.

What to do

In isolated trees, remove infected branches.

Scab Diseases

What it affects

Sorbus & Malus Species (Mouantain Ash, Whitebeam & all Apple Spp) Poplar Spp, Pyrus (Pear) & Willow.

Symptoms

Brown leaf blotches, Spots on fruit. Leaves die off but remain on shoot

What to do

Spray fungicide where appropriate.

Witches Broom

What it affects

Birch, Hornbeam, Cherry and Fruit Trees

Symptoms

Thick, dense clusters of live or dead twigs. Blooms flush earlier than rest of tree

What to do

Remove blooms

Peach Leaf Curl

What it affects

Cherry, Poplars and Alders

Symptoms

Whole leaves are distorted, blistered and discoloured. Leaves can fall early. Dead Twigs.

What to do

Remove host.

Coryneum Canker

What it affects

Cupressaceae macrocarpa, Leylandii & Western Red Ceder.

Symptoms

Scattered yellow brown foiliage in crown, top of tree dead.

What to do

Remove recently infected branches. If badly diseased, remove.

Tar Spot on Sycamore

What it affects

Sycamore

Symptoms

Large bituminous blotches with yellow outer rings on leaf surface.

What to do

On small plants, spray with a Bordeaux mixture, Rake and remove fallen leaves.

Bacterial Canker of Ash

What it affects

Ash

Symptoms

Dark, thick cracks on Stem. Dead Branches

What to do

Remove host.

Bacterial Canker of Cherry

What it affects

Cherries and Fruiting Trees

Symptoms

Yellowing leaves, Tree never flushing

What to do

Apply bactericide on fruiting trees where possinle.

Phytophthora Root Diseases

What it affects

Spanish Chestnut, Yew, Beech, Malus, Lime and Cherries Rarely oak and Leylandii.

Symptoms

All or some lower branches on one side die. Tree may die suddenly or even slowly. Tree will not fruit. Oftan occurs on wet sites.

What to do

Do not over water. No cure for diseased tree.

Phytophthora Blight of Holly

What it affects

Holly varieties

Symptoms

Small black spots on leaves, falling and turning black. No berries. Black patches on twigs.

What to do

Remove host if infected.

Phytophthora Bleeding Canker

What it affects

Horse Chestnut, Lime, Oak, Maple, Willow, Birch

Symptoms

Red/ Black, Yellowy brown gummy ooze on bark. Cracked bark with growing fungi.

What to do

Cut out all dead, dying bark and a 2’ strip of healthy bark with sterilised blade. Treat wound with paint on fungicide.

Wooly Beech Aphid (Grylloprociphilus imbricator)

What it affects

Beech Trees

Symptoms

In late spring, fluffy white patches appear on the underside of beech leaves. This covers pale yellow aphids that are sucking sap from the foliage and young stems. The aphids excrete a sugary substance called honeydew that coats the upper leaf surface and makes the foliage sticky

What to do

Control with pesticides is only feasible on beech trees and hedges that are small enough to be sprayed thoroughly. Affected plants can be sprayed in April-May when infestations begin. It is not worthwhile spraying later in the summer, as by then any damage has already occurred and the infestation will be past its peak and in decline.