I am regularly asked to provide advice on how to rehabilitate trees after pest or disease attack.
The following article guides gardeners through the process of diagnosing common problems and developing strategies to resolve pest issues in trees.
Note that in previous articles we’ve discussed soil compaction and tree root diseases, which also affect tree health.
TRIAGING AN UNWELL TREE
The most common problem appearing in sick trees is defoliation or dieback. This is evident when branches die in patches or large areas of the tree become devoid of leaves, as shown.
Dieback may be due to any of the following causes or a combination of them:
• Insect attack
• Soil compaction
• Waterlogged soils
• Fungal or mould diseases such as Phytophthora, which are sometimes associated with poor soil conditions or lack of airflow
This article focuses
