For years, trees are highly valued by the people of Hong Kong who love and care about them. The Greening, Landscape and Tree Management Section of the Development Bureau (DEVB) has been working to foster a culture of love of plants and trees through diversified community participation activities, and by encouraging public participation in tree risk assessment and enhancing public education and community surveillance on the health of the trees, in order to ensure public safety. To allay the worries of the public and foster a better understanding of the Government's tree management policies, we have compiled a list of common concerns and responses as follows:

General Situation

Q1: What are the duties of the Tree Management Office (TMO)? Arr
The Government adopts an "integrated approach" for the management of trees. Under this approach, the different departments responsible for the maintenance of an area or a facility are also responsible for the maintenance of trees there, so as to optimise the use of resources. The duties of the TMO are to co-ordinate the tree management work of different departments, enhance public education and community involvement, provide regular training, promulgate best practices, conduct relevant researches and resolve complex cases, etc., so as to facilitate the departments to manage the trees under their care in a more effective and professional manner.
Q2: How many trees have been planted by the Government in recent years? Arr
Please visit the Planting Records.
Q3: Do the TMO staff have the expertise to carry out their duties? Arr
Currently, the TMO has a total of 22 posts responsible for tree management. Most of these post-holders possess international professional qualifications in arboriculture, such as the International Society of Arboriculture (ISA) Certified Municipal Specialist, ISA Certified Tree Risk Assessor, ISA Certified Arborist, holder of Certificate in Professional Tree Inspection (LANTRA Awards UK) or honorary bachelor degree in arboriculture, etc.
Q4: Do the tree risk assessment methods adopted by the TMO comply with the international standards? Arr
We developed our tree risk assessment methods by mainly referring to the guidelines of the ISA, the U.S. Department of Agriculture and the relevant professions in the U.K. Thus, we follow the commonly-used international standards.
Q5: What would the DEVB do to enhance professionalism of management staff? Arr
The DEVB endeavours to improve training arrangements and works with tree management departments to formulate training plans to ensure that there are adequate professionals to take on management, supervision and frontline work and properly perform various tree management duties, and to uplift their academic standard, professional qualification or vocational skillsets, with a view to enhancing the tree management capabilities of tree management departments. The DEVB will sponsor tree management and tree care personnel to undertake tree management programmes offered by local or overseas academic and training institutions, and identify departmental personnel who meet the programme entry requirements to undertake the Preparatory Course and Examination for Certified Arborist offered by the International Society of Arboriculture and the Professional Tree Inspection Certificate offered by the Lantra Awards. Regarding vocational training, the DEVB will make reference to the six core job functions of the Specification of Competency Standards for the arboriculture and horticulture industry to draw up a variety of training courses, seminars or technical meetings for departmental management and frontline personnel.
Q6: What would the Government do to ensure that the tree risk assessment is effective in preventing injury arising from tree failure? Arr
Like other living things, trees undergo the life cycle of growth, ageing, sickness and death. Tree risk assessment allows departments to duly manage potential tree risk. Much effort is devoted to minimizing risk of tree failure at areas with high pedestrian and traffic flow. Notwithstanding that the health of a tree is subject to change over time and weather conditions (especially during inclement weather), we give our best endeavour at tree risk management.
Q7: Has the TMO made public details of the old and valuable trees? Arr
The publicly accessible Tree Register was established in July 2010. It contains such information as the distribution and overall conditions of Old and Valuable Trees (OVTs) and stonewall trees. The Tree Register is updated regularly. Departmental inspection officers assess the health and structural conditions of the trees on the Register and work out remedial actions and inspection timeframes (from several days to several months); while the TMO reviews the relevant risk assessment reports and conducts site inspections. Public can access the Tree Register website.
Q8: How would the Government ensure the performance standard of horticultural contractors? Arr

The Government attaches much importance to the performance of horticultural contractors, and diligently monitors their work performance in accordance with the service contracts.

The Government states clearly all necessary work requirements for compliance in horticultural and tree management contracts. If the performance of a contractor cannot meet these service standards, departments concerned will, depending on the situation and according to the contract, take action against the contractor.

Meanwhile, the TMO has already issued guidelines on proper pruning practices and irregularities that should be avoided (available here).

Q9: What are the procedures for tree removal (tree transplanting and/or tree felling) on private or leased land? Arr

If the tree concerned is located on leased land with tree preservation clause(s), removal (inclusive of tree transplanting and/or tree felling) of such tree is controlled by the relevant lease clauses.

Prior to any tree removal, the lot owner or his/her representative shall submit a tree removal application to the respective District Lands Office of the Lands Department for approval. The application shall include tree information, reasons of tree removal and compensatory planting proposals. No tree removal is allowed until written approval is obtained from the Lands Department.

For details and enquiries regarding tree removal applications, please refer to Lands Administration Office's Practice Notes Issue No. 6/2023 or contact the respective District Lands Office of the Lands Department.

Q10: Why doesn't the Government put the fallen trees or dead branches collected into the planters nearby for use as soil cover or compost, but send them to the landfills instead? Arr

Due care must be taken when using broken branches or tree trunks as mulch or compost. As these broken branches and tree trunks may be infected with diseases, using them as mulch may spread the diseases to other plants.

As a typhoon hits Hong Kong, a huge number of branches or trees may be damaged in a short time. The departments concerned will first clear or remove the trees that may endanger our lives or property. Then they will clear the trees that block the traffic in order to open up major highways and carriageways at the earliest instance to minimise the impacts on the public. Therefore, it is not practical to require the departments to inspect a huge quantity of fallen trees and broken branches to identify pest and disease in a short period of time right after the typhoon.

However, for the routine vegetation maintenance work including grass cutting, pruning in which disease parts are not involved, departments are encouraged to reuse and recycle yard waste.

Q11: Has the Government considered other more environmentally-friendly ways to process the dead plants in order to relieve the pressure on the landfills? Arr

Within the country park areas, the Agriculture, Fisheries and Conservation Department will turn plant waste into country park facilities, or stack them up at suitable locations to create suitable habitats for wildlife, and allow natural decomposition to occur.

As to the handling of plant waste, the departments concerned are studying how to make effective use of the compost or organic mulch as fertilisers in order to recycle plant waste. The DEVB will support the Environment Bureau"s work on the treatment of plant waste. The DEVB has also worked in conjunction with the tree management departments to launch a pilot programme with requirements to enhancing sustainability, such as the use of local compost and recycling felled trees, in a number of horticultural maintenance works. The Guidelines on Yard Waste Reduction and Treatment can be available here.

Q12: What should a private property management company do if poisonous plants are found inside a private property? Arr
In general, planting of plants with known toxicity is not recommended in areas easily accessible to the public. If poisonous plants are already planted within a property, warning signs should be erected next to those plants to discourage the public and vegetation management workers from direct contact with the poisonous parts of the plants. When opportunities arise, the property management company should consider replacing the poisonous plants with non-toxic ones for public safety's sake.

Brown Root Rot (BRR) Disease

Q13: From time to time, OVTs have been found to be infected with BRRD. Is there extensive infection in the territory? Does the GLTMS have any ways and means to tackle it? Is massive tree felling necessary to contain the spread of the disease? Arr
Although there is as yet any effective way to cure BRRD, we have some knowledge of its modes of transmission. The disease is caused by the aggressive fungal pathogen Phellinus noxius and can be spread through root contact, contaminated soil, ground water, surface water, and even through the air by dissemination of basidiospores. BRRD has devastating impact on our landscape. Once a site is infected, it must be completely disinfected. International best practice and policy position is to limit the spread to other trees and remove the infected tree as soon as practicable, including the root system of the infected trees and other plants and associated soil within the infection area.
Q14: Are the frontline staff qualified to treat trees infected with BRRD? Arr

To enhance the knowledge of frontline and management staff on the control of the pests and diseases of plants and trees, the GLTMS has organised a number of courses on their control, including the control of BRRD.

In addition, the GLTMS issued the Manual on the Management of Brown Root Rot Disease (the Manual) in 2019 to provide the proper removal procedures of and follow-up requirements for BRRD infected tree (available here). The steps are clearly illustrated for better understanding by operating personnel. A short video and a sample method statement on the same are also available here. The GLTMS has also commissioned researchers and consultants from local universities to conduct a number of studies on topics that include genetic diversity and population structure of Phellinus noxius in Hong Kong. The findings, which ascertained the prevailing control and management strategy, have been shared among the tree management departments and members of the industry.

Q15: Did the GLTMS make reference to overseas experiences in the treatment of BRRD? Arr
The GLTMS has been meeting the Urban Forestry Advisory Panel, which is made up of local and overseas experts, on the control and treatment of the disease and to explore ways to tackle it. In 2011, we shared and exchanged views with Dr C.H. FU and Dr B.Y. HU, two visiting experts in phytopathology from Taiwan, and conducted joint site visits to infected trees. Since 2011, the GLTMS has been working closely with tree management departments once suspected cases of BRRD infection were identified. The GLTMS will continue to collaborate with research institutions to conduct fungal surveys, and BRRD diagnosis and prevention studies on aspects such as resistant species and cure.
Q16: How to identify trees infected with BRRD? Arr

Identification of BRRD infected trees can be carried out through field diagnosis or laboratory diagnosis or the combination of the two. Typical symptoms of BRRD infection that could be identified by visual assessment of the tree crown(such as sparse foliage density, abnormal foliage size and colour, dieback twigs) and the entire lower trunk, root collar and individual roots (such as fruiting bodies, mycelial crust and nets, soil aggregates). A pictorial guide for identification for infected trees is available here.

In certain situations or tree species where the symptoms and signs of BRRD infection may not be obvious and field diagnosis will not be effective enough to confirm the infection, laboratory diagnosis involving fungal isolation and molecular diagnosis will be utilised to confirm the species of the fungi in the sample.

The Tree Management Practice Note No. 4 entitled "Management of Brown Root Rot Disease Infected Tree" was promulgated in 2020 to further promote the knowledge on BRRD to the general public and the industry, which is available here.

About Maintaining Trees for Private Properties

Q17: Is prior approval from the Government required for tree removal within private lots? What are the application procedures? Arr
In granting a plot of land, the Lands Department ("Lands D") executes a lease with the grantee who is required to comply with the lease conditions after becoming the owner of the land. Leases executed at different times contain varying conditions. Private lot owners have to check and comply with the lease conditions. Where there is no tree preservation clause in the lease of a private lot, the lot owner can employ qualified professionals to attend to the trees within the lot. Regarding the employment of qualified professionals, private lot owners can refer to the tree website of the Development Bureau for the list of contractors or professional bodies providing tree management services. Generally speaking, where the lease of a private lot contains a tree preservation clause, the lot owner has to, except in an emergency situation, make a prior application to the District Lands Office (DLO) of Lands D and obtain a written consent before removing or pruning trees within the lot. To apply for tree removal or pruning, the private lot owner is required to submit a report prepared by a professional meeting the requirements specified in the Practice Notes Issue No. 6/2023 available at Lands D's website, providing sufficient justifications and evidence for consideration. In granting a written consent, DLO may impose conditions on transplanting, compensatory landscaping or replanting as deemed appropriate. For application procedures for tree removal or pruning and guidelines on report preparation, please refer to the Practice Note Issue No. 6/2023 of Lands D. Further enquiries can be made to DLOs, the contact details of which can be found at the website of Lands D.
Q18: What action will the Government take if a private lot owner carries out tree removal or pruning within his/her property without approval? Arr
Where the lease of a private lot contains a tree preservation clause, if the lot owner carries out tree removal or pruning within the lot without DLO's written consent, appropriate action will be taken by DLO upon detection. Such action includes issuing warning letters to the owner, requiring the owner to carry out compensatory planting or pay a premium if retrospective approval is given.
Q19: Can tree removal or pruning be carried out by private lot owners in emergency situations? Arr
For the sake of public safety, tree pruning or removal can first be carried out by the owner of a private lot if the tree within the lot is considered to pose an immediate danger to the public after assessment by a professional employed by the lot owner meeting the requirements of the Practice Notes Issue No. 6/2023 and even though the lease of the lot contains a tree preservation clause. But the lot owner or his/her representative has to submit a detailed report prepared by the professional to Lands D within 21 days after the pruning or removal of the tree. The report should contain the justifications and evidence for tree pruning or removal, photos taken before and after the pruning or removal works, and the required compensatory planting proposal.
Q20: What action will the Government take if a private lot owner fails to properly maintain the trees within his/her property? Arr

Regardless of whether the lease contains any clause requiring the owner of a private lot to properly maintain the trees within his/her lot, it is the responsibility of the owner to properly manage his/her property including the trees planted on the lot. Private lot owners may be held liable for any casualty or property loss arising from their failure to properly maintain the trees within their properties.

In addition, if the lease contains clauses requiring the owner to properly maintain the trees and the owner fails to comply with the lease conditions, Lands D will, upon detection, take lease enforcement action in the capacity of the grantor of a government lease. Such action includes issuing warning letters to the owner concerned.
Q21: Apart from the "Handbook on Tree Management", how does the Government assist the private property owners to manage trees within their properties? Arr

The DEVB has been proactively organising seminars and field demonstrations for property management personnel to enhance their knowledge of tree risk assessment and proper tree care. To assist more private property owners to properly manage trees, the GLTMS speaks on the "Handbook on Tree Management" and the importance of proper tree care in the building management workshops organised by the Home Affairs Department for private property owners from time to time, and answers property owners' questions on tree management.

Every year before the wet season, the DEVB will organise "Public Talks on Tree Care before Wet Season" for property management personnel and the public, in which the contents include common tree problems, tree inspection and general tree care, etc. The key objective is to remind property owners the need to arrange qualified arborists to conduct tree risk assessment for the trees within their premises and implement necessary mitigation measures, such as pruning, removal of dead branches or removal of trees at risk, to protect the residents' and public safety.

To further enhance the awareness of private property management personnel on proper tree care, the DEVB has organised tree management workshops specifically for property management personnel since 2019.