Caring for Trees

About this pattern

For the first five years after a project delivery, the development organisation and residents are responsible for existing public trees and new ones, after which local government authorities take over caring for them. Those first five years are vitally important if the trees, planted and existing, are to be healthy and long-lived. During this time, the community and development organisation can establish policies and strategies for site trees, so that local government can continue with the foundational tree management afterwards, including the on-going appointment of a respected arboriculturalist.

Often people are afraid of big trees in public spaces or private gardens because they may drop branches or fall on cars or houses in severe storms. This can be addressed by consistent arboriculture care (for instance visit the Arboriculture Australia website in resources section). Trees can be encouraged to grow in particular shapes to remain amenable to social commoning. There are various stages to caring for trees so that branches do not fall, and trees remain healthy.

First, trees need deep friable soil, air and water. For trees in open space, start with the Keyline method of preparing planting areas (see the KEYLINE pattern). This will ensure healthy soil and water for good growth. Tree planting in streets and public space need adequate areas and depth of soil (see the pattern SELECTING SHADE TREES FOR PUBLIC OPEN SPACE)

Second, check and manage trees for insect pests Providing the proper cultural care in accordance with climate and needs of a tree species is the best way to prevent insect infestations. Eucalyptus trees, for instance, appreciate supplemental irrigation during prolonged dry spells and experts at the University of California Integrated Pest Management Program suggest watering eucalyptus plants once a month with a drip hose until the top 12 inches of soil become moistened and performing maintenance pruning when pests are waiting out the winter season, in order to avoid attracting insects into freshly cut wood tissue (see Kelsey [n.d.] in the references below).

Third, prune and maintain branch and trunk health to keep structural soundness to withstand storms and strong winds. This can include reducing the weight of the canopy by selectively pruning the ends of the branches.

Cable and brace where branches need more support or have been damaged. Cabling keeps tree branches from splitting at their junction. This involves attaching various types of cables to stronger branches, the trunk, the ground or other anchors. Cabling can also be used to support unusually long limbs or reinforce weak-wooded species.

Dynamic Cabling (or ‘Cobra’) allows the limbs to sway, putting less stress on trunk and branches. Thus, tree continues to produce reaction wood (special cells) in response to wind or other stresses. Dynamic systems generally use synthetic ropes instead of cables, and they usually wrap rubber around the branches being supported, rather than relying on metal hardware that has been screwed into the tree. Cobra system is a dynamic tree support system specially designed to be flexible and shock-absorbing with different benefits:

• Gentle to trees, self-adjusting to the diameter growth of tree, requires practically no tools, and incorporates a shock-absorbing unit;
• Avoids defective growth, the ‘karate effect’, abrasion and constriction, wounding;
• Encourages trees to grow reaction wood.

Cobra system components include cobra rope, anti-friction hose, expansion insert, shock absorbers (Arbor Culture Pty Ltd, n.d.)

Crown thinning and lifting allows more sunlight to pass and air to flow through the canopy. This is done by removing some secondary branches. Crown lifting raises the height of the crown and allows more space underneath for lawns and gardens.

Good Arboriculturalists can undertake these procedures and maintain your trees with annual inspections. 

Pattern Conditions

Enablers:

• Undergrounding powerlines means trees can grow full mature form. Streets can become signature avenues.
• Assisting local government to lobby for TAFE course on Arboriculture.
• Establishing a caring for trees community group is a positive step.
• Tree care gives opportunities for residents and children to learn to be ‘citizen scientists’ by monitoring specific trees (see Australian Citizen Science Association in the resources section).

Constraints:

• On-going cooperation with local government during and beyond the five-year period.
• Protocols required to prevent storage or emerging structures within canopy drip-line.

Commoning Concerns

Canopy Trees are one of the most effective ways to cool commons. ‘Cool commons’ are spaces and places offering cooler temperatures than surrounding areas.  Such commons are used by, and are accessible to, a community of commoners who, to some degree, care for, take responsibility for, and benefit from this coolness.

Access: Unrestricted access and involvement; restricted when undergoing care

Use: Recreation, Biodiversity, wildlife corridors

Benefit: Environmental benefit, carbon capture, amenity of public space

Care: Developer; Local Government; Body Corporate; community; arboriculture consultancy.

Responsibility: Developer; Local Government; Body Corporate; community.

Ownership: Body Corporate; community.