Posted by Nathaniel Hardy on Mon, Nov 20, 2017 @ 7:49 AM
The Urban Forest and Urban Greening are increasingly being recognised as hugely beneficial to society. These benefits are so well understood that tree planting is a commonplace requirement of many building permits and development approvals.
Traditionally though, this has often been a half-hearted affair – with budgets dwindling at the end of the construction, subpar trees are chosen, and lowest cost planting methods are utilised. Let’s be clear, low cost is not the issue. Its low ROI and low lifetime value of the green asset that we are looking to improve.
Huge amounts of all tree maintenance issues are a result of a poor decision at design, poor planting methodologies or issues during early tree establishment.
That is the end of the rant… NOW…
Complaining about a problem without proposing a solution is called whining. Theodore Roosevelt
Some Ideas on the Solution
Handover inspections – Assess your trees before the contractor handover period ends
Inspection of trees should be conducted at least twice prior to handover of landscaping to any asset holder one of these should be in the growing season and well after planting to allow the trees to respond to planting treatments. These inspections should be completed by an urban forester, arborist, or soil scientist. If any concerns are raised nutrient testing of soil or leaf nutrient tissue should be done or a full arborist report should be completed if the trees are significant. This enables any issues to be identified and also allows time for the contractor to rectify these issues prior to handover. This is all about making sure the tree achieves its intended social or economic ROI for the community. This inspection also reduces risk of later issues with the tree and reduces cost of lifetime tree maintenance.
Review tree planting codes
If you are in the role of developing a planting guideline for urban trees then consider these things;
- Tree species – Assess what value trees are currently providing in your area. Remember that human habitat value is just as important as wildlife habitat value, because if residents value trees then the process is much smoother. Local trees can provide shade in summer, sunlight in winter (deciduous trees), visual amenity colours or flowers (tourist attraction), wind protection, high canopies that are natural or lifted to allow lines of sight to be maintained. These are just a few. Talk to your local Landscape Architecture Association, these designers carry a wealth of knowledge. #American Society of Landscape Architects #Australian Institute of Landscape Architects #International Federation of Landscape Architects
- Planting Details / Planting Requirement – Trees need their roots and their roots need soil to grow into. Just thought I’d let you in on that little secret. If you only give your trees a very small amount of root volume / Small tree pit you will have one of these.
Bonsai – tree or shrub that has been dwarfed, as by pruning the roots and pinching, and is grown in a pot or other container and trained to produce a desired shape or effect.
Urban Bonsai – A tree or shrub planted into compacted subgrade. Root growth is limited due to compaction and tree growth is stunted. Occasionally tree root balls are pruned to ensure it fits into is new home. Urban bonsai often results in conflicts between tree roots and pavement causing maintenance headaches.
Enforce the Codes
- Handover inspections – Inspect the green assets just as would be done for hard assets
- Use suitability qualified professionals to review tree planting compliance and tree health prior to handover
- Extend handover and maintenance periods for price significant or amenity significant tree plantings to ensure that trees are
- Hold bonds – Tree valuation is a science and accurate financial values can be placed on trees. This method can be used for both new plantings as well as protecting current tree installations.