In a high-density city, transplanting is one of the mitigation measures to strike a balance between development and conservation. In Hong Kong, transplanting is a common option apart from direct removal if a tree conflicts with a permanent structure.

Tree transplanting means digging, taking away and replanting of trees from one location to a new location.

A decision to transplant should be based on different factors: tree conditions (e.g. form, health and structure), size, species, conservation status, amenity value, environmental and cultural factors, public opinions, engineering considerations and cost-effectiveness.

To increase the trees' survival rate, careful planning and preparation before the transplanting are necessary. The brief procedures are as below,

• Design and Planning

The sites and tree conditions shall be fully evaluated by a tree specialist. Preparation works shall be well prepared and studied. For example, the number of root cutting phases, the extent of root cuts, size of root ball during transplanting, hoisting and transportation requirements, method statement, tree monitoring and post transplanting maintenance procedures. Besides, safety precautions, locations of surrounding utilities and receptor site conditions shall also be taken into consideration.

• Transplanting operations

When preparation completed, transplanting shall be operated under the supervision and guidance of tree specialists. The process including preparing tree root ball with suitable dimensions, excavation in phases and root pruning. Sometimes, crown pruning is carried out in the operations to remove unhealthy, damaged, diseased, dead and crossed branches. If the tree is transplanted off-site, sometimes the tree has to be crown reduced to fulfill road traffic requirements. Tree lifting and planting shall only be operated once the receptor is ready.      

Before uplifting, tree trunk and main branches shall be properly protected to prevent injury during the transplanting operation. The root ball should be properly wrapped until the uplifted tree is transplanted to its new location.

During planting, the root flare cannot be covered. Proper planting depth shall be maintained. The backfilled soil shall be lightly compacted and filled by layers to prevent future subsidence. It shall not be compacted to a density that inhibits root growth too.

• Post-planting Care

Because the tree is root cut significantly, transplanting has an adverse effect on tree structural stability and health. It is termed as transplanting shock. Regular tree risk assessment and proper maintenance shall be conducted after transplanting, especially checking the growth of new tree roots. A well regenerated root system confirms the recovery of tree health and anchorage.

Tree transplanting service from Tak Tai:

• Making assessment and monitoring by a certified arborist, transplanting specialist and registered safety officer.
• Giving professional advice, formulating and executing tree transplanting based on customer requests and actual situations.
• Providing a one-stop service including tree protection, tree risk assessment and tree maintenance service.