What is interesting is his research work is backed by years of extensive studies and experiments and is not merely based on a few isolated experiments. It shows the amount of forward and detailed planning that was done before he launched into executing the projects. There were a lot of take home messages and I have summarized the key ones briefly as follows:
- A recommended root system has roots that grow straight out. Such a root system has a more desirable wide network of fine roots and root hairs and gives the tree more stability to withstand external forces e.g. strong wind, that may damage it.
- When re-potting a tree in the nursery or planting a potted tree out into the site, it is pertinent to shave away the roots on the outside to remove root defects e.g. turning roots, to enable the roots to grow properly.
- Laying gravel and adding reinforced bars above a tree's surface roots before installing a concrete footpath over it reduces the incidence of the roots lifting up the footpath compared to just merely installing the concrete footpath over the surface roots.
- Laying mulch on the rootball does more harm than good to trees. Mulch should be laid outside the rootball instead.
- The desirable attributes of a tree include a single dominant leader, distinct root flare with straight growing roots, right-angled branches and an even distribution of leaves throughout the crown.
- Formative and structural pruning to remove co-dominant trunks, included bark union, girdling roots, upright branches, lion's tailing and to reduce the branch-trunk aspect ratio is essential to achieve the above desirable traits and to maintain the tree's longevity in the landscape.
- Horizontal branches are stronger than upright branches.