|Damage from flowerbeds raised around the base of a tree:
If it is a small bed that only covers a small percentage of the root zone, the damage is limited to keeping the bark wet and leading to rot and other diseases. If the bed covers a large portion of the root system, there is the added injury of smothering the feeder roots, causing oxygen deprivation. For the tree's benefit, build no raised beds under trees. If it must be done, limit the area and add little to no additional soil.