Trees and Woodlands | Woodland Heritage | Tree Species in the British Isles | Woodland Grant Schemes | Trees and the Law | Woodland Crafts | Pests and Diseases

There are a large number of pests, diseases and disorders that affect our trees. These include insects, fungi, bacteria, viruses, mammals, genetics, weather, chemicals, pollution and people. With all of these adverse factors working against them, it is a wonder that they survive at all.

Fortunately, trees have in-built genetic defences that have allowed them to survive the rigours of the world since pre–history. On the other hand, with the onset of the human population and our disruption to the living cycle, trees are having to work harder still. Unfortunately, they are not always winning.

The biggest pests to trees are humans – yes, we're scarier to a tree than all of the creepy crawlies that are associated with them. We pollute them, build around them, sever their roots, throw de–icing salt at them, vandalise them, set fire to them, prune them improperly, compact and contaminate their soil, drive nails into them, remove them without thought, plant them in the wrong places, plant them incorrectly, flood them, forget to water them and then damage them with grass cutting machinery.

Fortunately, there are a large number of associations, organisations, courses, professionals, organised volunteers and general enthusiasts who are striving to develop training, consultancy, advice, projects and initiatives to protect, prolong and enhance the health and safety of our trees.

Tree Care and Maintenance
Pests, diseases and disorders that are distressing trees are numerous, rarely simple to identify and even more difficult to treat or correct. However, at the end of the day, trees are a lot like humans – a healthy diet, a stress free environment, general care and support will allow trees the greater defences needed to battle pests and diseases and to live longer, healthier lives.

Possible Signs & Symptoms of an Unhealthy or Structurally Unsound Tree

• Fruiting bodies (toadstools and fungal brackets)
• Loss of vigour
• Early leaf fall
• Early autumn colours
• Brown or yellowing leaves
• Curling leaves
• Branch drop
• Deadwood
• Insect bore holes in the leaves or the stem
• Notches in the leaves
• Crown dieback
• Damaged bark
• Cavities
• Cankers
• Weeping wounds
• Insects
• Tree failure
• Windthrow
• Death of tree

These signs and symptoms do not automatically mean that your tree is unhealthy or dangerous and further investigation is often required. There are generally a number of factors to take into consideration and a full inspection of the tree and its environment should be carried out.

If you suspect that your tree is unhealthy or even dangerous, it would be prudent to consult a professional to determine the cause of the problem and the appropriate solution. This would consist of contacting a qualified, reputable and insured arborist (historically known as a tree surgeon) or arboricultural consultant. It is also prudent to ensure that they are members of affiliated associations and have recognised qualifications. These are currently found in the Yellow Pages under 'Tree Work', 'Forestry Maintenance Services' and 'Garden Services'.

Recognised industry associations include the ISA (International Society of Arboriculture) .

Qualifications in arboriculture can include the following:-

• NPTC competencies for chainsaw use and tree climbing (this is essential for contractors carrying out tree works)
• NC (National Certificate)
• HNC (Higher National Certificate)
• ND (National Diploma)
• HND (Higher National Diploma)
• BSc (Honours)
• MSc
• Certified Arborist (ISA)
• Techicians Certificate (AA)
• RFS Professional Diploma

Any professional consulted or making any recommendations on trees should carry Professional Indemnity Insurance and any professional carrying out tree works should carry Public Liability Insurance.

Before any works on a tree are carried out, it is advisable that you know your legal rights and obligations in respect to ownership of trees. Please see Trees and the Law for further details.

There are a range of organisations that can provide advice on tree pests, diseases and disorders. There are also a number of e-mail forums where questions can be posted for advice. For further links, please click here.