Q&A: Urban Yard Waste in Hong Kong
| Dr. Law Man Yee, Caroline - Assistant Professor, Department of Environment Faculty of Design and Environment, THEi
1. What is the problem
with disposing yard waste in landfills?
Our urban forests provide many ecosystem services. However, when dead
plants are disposed of at landfills as yard waste, it does not just take up
resources and occupy landfill spaces. They also generate landfill gases, like
methane and carbon dioxide.
According to the "Monitoring of Solid Waste in Hong Kong Waste
Statistics for 2020 Report” published by the Environmental Protection
Department (EPD), food waste, paper waste and plastic waste (30%, 24% and 21% respectively)
accounted for the majority of waste disposed of at landfills in Hong Kong. Yard
waste only accounted for 2.1% (222 tons per day) .
Yard waste contributed merely 2.1% to Hong Kong’s solid municipal waste.
It sounds that it was just a scant quantity. But it does not mean that we can
continue to dispose these biodegradable materials in landfills. It is our top
priority to understand and address the root of the problem. In the last ten
years, the recycling rate of yard waste in Hong Kong was less than 3% (2,000
tons). There is a large room for improvement (60,000 to 70,000 tons was
disposed of at landfills each year in recent decade).
2. What are the developments
in recent years?
- EPD set up a Yard Waste Recycling Centre (Y·PARK) at Tsang Tsui, Tuen Mun, which commissioned on June 2021. Y·PARK converts wood
waste into usable materials, such as compost, biochar or for upcycling. Y·PARK does not
receive grass clippings, leaves and small branches (except those attached on
- The government is currently funding educational institutions and industries
to promote environmental protection projects. For instance, the THEi Bachelor
of Science (Hons) in Horticulture, Arboriculture and Landscape Management
Programme received funding support from the Environment and Conservation Fund
in November 2019 to promote the "ECF Yard Waste – Pilot Scheme for
Private Housing Estates" and
encourage the society to start yard waste recycling. The pilot provided equipment
for three private housing estates in Hong Kong, along with technical support,
to help the horticultural and property management staff make compost from their
yard waste and facilitate sustainable yard waste management. This project also
offered online workshops to educate the public.
3. What are the
reasons/difficulties for the low recycling rate of yard waste in Hong Kong?
- Landscape and property management industry and the public rarely have
the relevant knowledge and expertise. They have limited knowledge on proper
disposal of yard waste, and they are not familiar with "onsite composting”
or lack of equipment like shredders and
- Most of the grass clippings, leaves and small branches produced by green
space maintenance are transported to adjacent landfills for disposal, and there
is a lack of incentive to change such practices.
- When local arborists cut down urban trees, twigs and leaves are
separated for ease of transportation. However, detached twigs and leaves are
not accepted by Y·PARK. To avoid doubling transportation costs, these twigs and leaves,
along with the large trunk, will be disposed of at nearby landfills.
4. What is the way out
for yard waste?
- Although the government only has one remote yard waste recycling centre
at present, "on-site composting” to reduce waste at source is essential before
the implementation of the waste charging scheme. What’s more, Y·PARK currently does
not accept grass clippings, leaves or small branches.
- All sectors should compost their own yard waste, such as grass
clippings, leaves and small branches, as much as possible.
- Larger and high-quality trunks can be upcycled into woodcraft,
furniture, and more.
- Lower quality wood waste and chippings can be made into various
products, such as compost, wood chip and biochar. A variety of by-products can
be made, such as deodorant products, filtering products, and construction and
5. What urban settings
are suitable for "on-site composting”?
Housing estates, shopping malls,
schools and other venues with green space in Hong Kong can consider "on-site composting”, based on available space
6. What are the
considerations to start "on-site composting”? Is it cost-effective?
The following considerations are
applicable for small and medium-sized venues in urban areas. Large-scale venues
will require more investment.
Equipment: In order to process smaller tree
branches (<4 cm diameter), an electric shredder is a suitable choice for
small and medium-sized housing complexes. Three compost bins and an electric
shredder cost around HK$4,000. In the survey for the pilot, more than 70% of
respondents believe that this is an acceptable price, and that the equipment
will last for many years.
Space: Property managers usually want to reduce the impact of compost bins/composting
process on the surrounding landscape and will select inconspicuous spaces to
place them. As three compost bins take up limited space (less than one square
meter each), it is not difficult to find a space for them, even including the
workspace reserved for composting needs. If there is a lot of yard waste, there
is a need to increase the number of compost bins.
Manpower and Expertise: Normally, a
property management staff member can be deployed in charge of supervising the
on-site composting process, supported by two front-line workers (one
responsible, the other supporting). In the early stages, it would be ideal to
find a person experienced in this field to monitor the progress and provide
regular guidance. In the survey, respondents generally agreed that manpower
input of two to three hours per week is acceptable.
Hygiene: As long as the plant material ratio and moisture amount is properly
controlled and air circulation is maintained, on-site composting generally will
not lead to any hygienic problems. The housing complexes that participated in
the pilot mentioned that composting did not bring about adverse environmental
impacts to them.
If you want to know more, please view the programme summary
7. How to produce
Please refer to the video and booklet below:
Online classroom – How to make yard waste compost
Download [A guide to on-site composting of yard waste at housing estates]
8. How can various
sectors promote yard waste reduction and recycling?
- The government can subsidize more venues to purchase equipment and also
the course fee to support relevant personnel to participate in on-site
- Participation from different sectors of the society is essential.
Through practicing on-site composting, the private sector, such as residential
and commercial buildings, can enhance interaction between property
management/shopping malls and residents/customers and ESG performance. NGOs and
educational institutions can organize courses, workshops and neighbourhood
collaboration to realize yard waste management and compost production.
- As for the government, contractors for government greening maintenance contracts
should be required mandatory to make "on-site composting” using grass
clippings, leaves, and small branches (except medium and large branches),
subject to site conditions. It can be done step-by-step at the beginning of the
- The arboricultural industry can set up their own wood chipping and composting
equipment at their depots/nurseries, where site conditions allow.
- Wood crafting companies, landscape and horticultural companies, and NGOs
can cooperate to apply for grants or funds to establish an online matching
platform to connect wood log donors and users, preferably within the same
district to reduce transportation process. The matching platform can play a
coordinating role for the sorting and upcycling of large or high-quality
 Monitoring of Solid Waste in Hong Kong - Waste Statistics for
Yard Waste Pilot Scheme for Private Housing Estates Website: http://yardwaste3r.org
Yard Waste Recycling Centre [Y · PARK] Website:https://www.ypark.hk