Aker said the biggest tree-killer is, by far, root damage by the owner. And tree-maintenance is mostly for the birds. Trees generally do not require water in addition to the amount they get from Mother Nature, except in times of draught, said Aker. Fertilizer and mulch are in the same category. Prune out dead branches for safety purposes and try not to disturb the root system.
Several factors can be at the root of a root problem.
Compacted soil can cut off the necessary oxygen supply to a tree's roots. A car parked under your tree. Digging can seriously damage roots as well. For example, planting a cable line or new drainage line can cut into tree roots and eventually result in the death of the tree. Certain trees, naturally prone to having shallow roots, lose oxygen and die when they are covered by thick flower beds .