What is arboriculture?

The science and practice of the cultivation, establishment and management of amenity trees for the benefit of society.

Arboriculture refers to the care of trees grown or maintained for their amenity value – for the environmental, social and economic benefits that they bring – rather than for the value of their timber or fruit. It also involves tree safety and tree risk management, as many of the trees looked after by arboricultural professionals can be found in close proximity to people.

There are many different roles and careers in arboriculture. This includes nursery workers, groundspeople, tree surgeons, tree officers, consultants, researchers, trainers, policymakers and more. 

There are close connections and links between arboriculture and other tree-related and environmental professions and disciplines such as woodland management, forestry and horticulture. However, despite some overlaps arboriculture is a profession in its own right, distinct in many ways from these other sectors. 

Young Tree Maintenance

Video Guide

Arboricultural Association Technical Director John Parker runs over some important basic young tree maintenance.

Acute Oak Decline Oak

Acute Oak Decline –
Acute Oak Decline (AOD) is a disease affecting several thousand native oak trees in Britain. It is considered to have first occurred in Britain 30-35 years ago. It mainly affects pedunculate oak (Quercus robur) and sessile oak (Quercus petrea), however other species of oak can also be affected.

Emerald Ash Borer Agrilus planipennis Ash

Emerald Ash Borer – Agrilus planipennis
Emerald Ash Borer (Agrilus planipennis) (EAB) is an exotic beetle which causes significant damage to ash trees (Fraxinus species). A native of eastern Asia, it is not known to be present in the UK.

Asian Longhorn Beetle Anoplophora glabripennis Many

Asian Longhorn Beetle – Anoplophora glabripennis
Asian Longhorn Beetle (ALB), Anoplophora glabripennis, is a native of China and the Korean peninsula, and poses a serious threat to a wide range of broadleaved trees. It has caused extensive damage to trees in the USA and Italy since being accidentally introduced there in recent years.

Elm Zig-Zag Sawfly Aproceros leucopoda Elm & Others

Elm Zig-Zag Sawfly – Aproceros leucopoda
The Elm Zig-Zag Sawfly, Aproceros leucopoda, has now been confirmed in Britain following a rapid expansion across Europe from eastern Asia. This page briefly describes the biology of the species, the risk it poses to elms in Britain, and its identification. To report a sighting of this species, please use Tree Alert.

Oak Wilt Ceratocystis fagacearum Oak

Oak Wilt – Ceratocystis fagacearum
Ceratocystis fagacearum (C. fagacearum) is a destructive fungus which causes wilt in oak trees in eastern and mid-western states of the United States. It causes extensive damage, particularly to species in the ‘red’ oak group (Quercus section Lobatae; syn. Erythrobalanus), but it can also damage ‘white’ oaks (Quercus section Quercus).

Canker Stain of Plane Ceratocystis platani London Plane

Canker Stain of Plane – Ceratocystis platani
The ascomycete fungus Ceratocystis platani causes canker stain, also known as plane tree wilt, on several plane species, including London plane (Platanus x acerifolia) and its parents, P. orientalis and P. occidentalis.

Sweet Chestnut Blight Cryphonectria parasitica Sweet Chestnut

Sweet Chestnut Blight – Cryphonectria parasitica
Sweet chestnut blight is caused by a fungus of Asian origin called Cryphonectria parasitica. Several cases of the disease affecting sweet chestnut trees have been found in England since 2011.

Red Band Needle Blight Dothistroma septosporum Pine

Red Band Needle Blight – Dothistroma septosporum
Dothistroma Needle Blight (DNB) (Dothistroma septosporum), also known as Red Band Needle Blight because of the colourful symptoms it shows on pine, is an economically important disease of conifers. It causes premature needle defoliation, resulting in loss of yield and, in severe cases, tree death.

Chalara Dieback of Ash Hymenoscyphus fraxineus Ash

Chalara Dieback of Ash – Hymenoscyphus fraxineus
Chalara dieback of ash is a disease of ash trees caused by a fungus called Hymenoscyphus fraxineus. It is particularly pathogenic to European ash, fraxinus excelsior.

Larch Tree Disease Phytophthora ramorum Larch & Others

Larch Tree Disease – Phytophthora ramorum
Phytophthora ramorum (P. ramorum) is a a fungus-like pathogen called a water mould. It causes extensive damage and death to a wide range of trees and other plants.

Shoot Blight of Cedar Sirococcus tsugae Cedar

Shoot Blight of Cedar – Sirococcus tsugae
In recent years severe shoot blight and defoliation of Atlantic Cedar has been reported from a range of locations in Britain. In late autumn 2013, samples from affected trees were received by Forest Research and the fungus Sirococcus tsugae was identified as being consistently associated with these symptoms.

Pine Processionary Moth Thaumetopoea pityocampa Pine

Pine Processionary Moth – Thaumetopoea pityocampa
Pine Processionary Moth (PPM), Thaumetopoea pityocampa, is not currently known to be in the UK. PPM has been extending its range across Europe, moving northwards through France since the 1990s.

Oak Processionary Moth Thaumetopoea processionea Oak

Oak Processionary Moth – Thaumetopoea processionea
Oak processionary moth (Thaumetopoea processionea, OPM) was first accidentally introduced to parts of South East England in 2005. European Union legislation was introduced in 2014 that recognises unaffected areas of the UK as being a ‘protected zone’.

Phony Disease of Peach Xylella fastidiosa Many

Phony Disease of Peach – Xylella fastidiosa
Xylella fastidiosa, also known by Pierce’s disease of grapevine, is a bacterium which causes disease in a wide range of woody plants, such as citrus and olive trees and in grape vines. Whilst not known to be present in the UK yet, it has the potential to infect several species of broadleaf trees.

KEY: (As of Autumn 2018)

  Not Currently Present
  Already Present

More information

The Forestry Commission has also produced the following information about pests and diseases and associated biosecurity. Click a link below to find out more.

For more information on pests and diseases and how we can help reduce their spread, take a look at their website: www.gov.uk/guidance/prevent-the-introduction-and-spread-of-tree-pests-and-diseases

Information contained on this page are © copyright of the Forestry Commission and are used with their permission.

Tree Selection, Planting and Maintenance

Selecting the right tree for the right place

Planting a tree in your garden is a decision requiring forethought and planning. Consideration must be given to the surrounding landscape and buildings, space available, soil type and location of the particular site.

Careful thought will help to ensure that an appropriate species is selected for the particular location, so giving the tree the best chance of successful establishment and future growth.

The Trees and Design Action Group (TDAG) offer comprehensive guidance with their resource Tree Species Selection for Green Infrastructure: A Guide for Specifiers, which includes information for over 280 species on their use-potential, size and crown characteristics, natural habitat, environmental tolerance, ornamental qualities, potential issues to be aware of, and notable varieties.

Further advice and information can be obtained from the Help & Advice section of this website as well as an AA Registered Consultant.

Tree planting

It is essential that young trees are given every opportunity to survive planting. Poor planting practices can result in long-term problems and even the death of the tree.

Information on how to plant your trees can be obtained from a competent Arboricultural Consultant, a competent Arboricultural Contractor, Specialist tree planting contractors or Tree nurseries.

Maintenance in the first few years following planting is crucial to ensure establishment. Young trees need TLC:

Tree maintenance

Most trees do not require regular pruning but there are occasions when tree work is necessary. You must take great care in deciding who you will take advice from.

Trees can suffer ill health from pests and diseases and or as a result of climatic or environmental changes.

If your tree looks unwell, appears different to normal or you consider that tree works might be required, you can obtain guidance and advice from the following sources:

How can I get a Tree Preservation Order made on a tree that I think is at risk of being felled or damaged?

Your local council is responsible for making Tree Preservation Orders (TPO). You should contact your local authority and speak to the tree officer or someone in the planning department who should determine whether the making of a TPO is appropriate.

More detailed information on TPOs: www.gov.uk/guidance/tree-preservation-orders-and-trees-in-conservation-areas#Flowchart-1-Making-and-confirming-TPO

Can I stop my neighbour building close to my tree?

You may be able to depending on the importance of the tree, the nature of the building proposed and distance between the proposed building and the tree in question.

If the building work proposed requires planning consent, all trees which could potentially be affected by the development (including those on adjoining property) should be assessed by an arboricultural consultant in accordance with British Standard BS5837:2012 Trees in relation to design, demolition and construction – Recommendations, and details of this assessment submitted with the planning application. The Local Planning Authority should consider how the proposed development will affect trees in accordance with the same document and, if the process works correctly, this should prevent unacceptable damage from occurring to your tree. If you are concerned, you should instruct an arboricultural consultant to assist and if necessary, make a formal objection to the planning application within the statutory timeframe.

If the work proposed does not require planning consent, it may be less easy for you to influence. If your tree is protected by a Tree Preservation Order (TPO) or is located within a conservation area, legislation relating to tree protection overrides that of permitted development rights, and developers will risk prosecution if protected trees are damaged. If you consider that your tree provides sufficient public amenity value to warrant protection by a TPO, you can make a formal request to the Local Planning Authority to place a TPO on your tree. An arboricultural consultant can advise you on these matters.

Further information:

Distancetpotree preservation orderlocal planning authoritybuildingconstructionneighbour

Find a Professional
If you need advice or tree management services - always use an Arb Approved Contractor (Tree work) or a Registered Consultant (Arboricultural consultant).

Choosing your Tree Surgeon

Good Climbing Practice

Good Climbing Practice

Bad Climbing Practice

Bad Climbing Practice

If tree work is not done properly it could lead to:

  • INJURY to people*
  • DAMAGE to property*
  • SERIOUS HARM to your trees that have taken many years to grow…

All through ill-advised and badly executed tree work.

*Potentially you may be liable is a 3rd party is affected.

Questions you should ask an arborist

Stage 1
Ask for a quote**

(a reputable arborist will always give a positive response)

  1. Are you insured?
    If YES. please show evidence of insurance – Employers’ Liability & Public Liability (recommended minimum of £5 million).
  2. Do you work to a British Standard?
    If YES, which one?
    Should be BS3998: 2010 ‘Tree Work – Recommendations’.
  3. What qualifications do you and your staff hold? (ask to see copies)
    Compulsory: MIUST have NPTC/Lantra Awards*** certificates for chainsaw use.
    Recommended: Certificates for other skills and machines. Arboricultural knowledge e.g. National Certificates and Diplomas in Arboriculture.
  4. Will you provide a written quotation?
    If NO, reject the contractor.
  5. Are you a member of a professional organisation?
    Membership does not guarantee work standards but does show a degree of commitment.
  6. Can you provide me with the phone number of a referee who can show me some of your work?
    If YES, follow up the reference.

**Obtain more than one quote, ideally 3.

***NPTC and Lantra Awards are national organisations that assess competence of people using chainsaws and other arboricultural equipment. Competent arborists will be able to show you an A4 sized certificate or plastic ID card if requested.

Tree work operations (arboriculture) require a high degree of technical competence, supported by training and experience. For these reasons tree work should only be undertaken by well-trained, competent arborists experience at the type of work being undertaken, e.g. tree pruning/tree removal.

Stage 2
Choosing the quote that suits you

When you receive your quotations check they include the following before deciding which one to accept:

  • Reference to BS3998: 2010 ‘Tree Work – Recommendations’
  • Clear and full details of the work to be undertaken (the specification).
  • What will happen to the timber and brushwood?
  • What will happen with the tree stumps?
  • Whether VAT is included.
  • Who will be responsible for obtaining permission if the trees are protected?
  • What steps will be taken to protect you and your property (the risk assessment)?

Be aware that there may be a limited quote validity period.

Stage 3: Consumer protection

If problems arise you can get help and advice from industry bodies such as the Arboricultural Association, International Society of Arboriculture or TrustMark.

Competent arborists

In the UK there are two recognised schemes certifying the competence of arborists through examination and regular re-assessment or Continuing Professional Development (CPD).

The ARB Approved Contractor Shield

The Arboricultural Association (AA) maintains an online Directory of quality assured tree surgery businesses. they are regularly assessed for their health and safety procedures, office and business practices, including customer care, as well as their quality of tree work. they will display the AA ARB Approved Contractor logo.

Check whether the contractor’s approval is current on the Arboricultural Association website via the ‘Find a Tree Surgeon’ link.

ISA Certified Arborist

Individual arborists may be certified by the International Society or Arboriculture (ISA). The ISA assesses the individual for their knowledge and ability. Certified arborists will display the ISA Certified Arborist logo.

Please check with the Society that the arborist’s approval is current, throught the ISA website www.isa-arbor.com/.

Other arborists may be equally competent. If they do not subscribe to either of the above schemes you should take more care to follow up the advice contained in Stage 1 & 2 above.


There is no shortage of people and companies offering tree work services, but how do you choose between them? The Health and Safety Executive says,

clients engaging contractors to undertake tree work need to carefully check they have the necessary skill and competence. Tree work is hazardous; to be done safely it requires properly trained and experienced people… Arboricultural trade associations can supply details of approved contractors and information to help you choose a competent tree work contractor…

It is equally important that advice given in respect to trees is correct and from reliable professionals. People and companies in this directory have satisfied the Arboricultural Association that they are competent to provide the consultancy and contractor services as described.

Recognising an ARB Approved Contractor

A great way to recognise a competent Tree Surgeon is to look out for the ARB Approved Contractor Shield. The shield is relatively new and chances are your local Tress Surgeon may still be displaying the old logo. Indeed, just because you see the old logo it does not mean they are not approved, just go to our directory page to check out a Tree Surgeon to give you peace-of-mind. We only show Tree Surgeons who have been approved and who have been assessed.

The ARB Approved Contractor Shield

People at risk:

Number 1No head injury protection (helmet)

Number 2No eyesight protection

Number 3No hearing protection

Number 4No fall protection (platform, rope and harness etc.)

Number 5No cut protection (chainsaw resistant trousers and boots)


Number 6No head injury protection (helmet)

Number 7No protection from traffic (high visibility clothing, road signing and traffic management)

Other people

Number 8Pedestrians and residents at risk of being hit by timber

Number 9Vehicles at risk of being hit by timber


Number 10Damage to fencing and other garden features

Number 11Damage to street infrastructure

Number 12Damage to a valuable tree

You could be at risk if you employ a tree surgeon or tree advisor who works like this and causes harm, injury or loss to yourself or anyone else.

Spot the difference

Spot the difference between these tree surgeons

Number 1No helmet

Number 2No eye protection

Number 3No hearing protection

Number 4No fall protection

Number 5No cut protection

Number 6Outdated chainsaw

Number 1Industrial chainsaw helmet

Number 2Full-face visor including eye protection

Number 3Ear defenders for hearing protection

Number 4Rope and harness for fall protection

Number 5Chainsaw trousers / boots for cut protection

Number 6Modern chainsaw with safety features

Choose carefully

By choosing tree surgeons from this directory you have the security of knowing that each person or company has passed the Arboricultural Association's rigorous and industry recognised standards of safety and tree care. All home/landowners have a responsibility* to engage competent people to work on their property. If you choose to use a contractor not listed in the directory the following checklist can help you establish the contractor's competence.

*Common law duty of care responsibilities and sometimes liabilities under the Occupiers' Liability Acts of 1957 & 1984.

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Arboricultural Association
The Malthouse, Stroud Green, Standish, Stonehouse, Gloucestershire GL10 3DL

Arboricultural Association Ltd. A company registered in England at The Malthouse, Stroud Green, Standish, Stonehouse, Gloucestershire GL10 3DL, UK. Company number 4070377.
+44 (0)1242 522152 | admin@trees.org.uk

The Arboricultural Association is a registered charity no. 1083845.

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