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.
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.
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.
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.