Home > Tree structure basics > Structural defects > Trunk bends or leans > Soft soil and bad pruning
Soft soil and inappropriate pruning caused the lean
Roots
were not cut on this leaning tree. The soil became soft when 15 inches of rain
fell in less than 24 hours. The top heavy canopy combined with the soft soil
in a hurricane resulting in the tree rotating in the soil.
Structural pruning on elms and other shade trees is important because it helps reduce this damage in storms. Structural pruning would have removed the upright portions of many of the larger stems, thus reducing the overturning moment (force) on the base of the trunk. This increases the likelihood of trees remaining upright in storms.
Treatment: These trees could be righted and staked for a couple of years in hopes that roots would develop enough to hold the tree firm in the soil. Enough root structure might develop to keep the tree erect for a number of years. However, these trees are more likely to fall over in future storms than trees that did not blown over. We really do not know for sure how large a tree should be righted after a storm. Probably trees larger than about 4 inches trunk diameter will be less likely than smaller trees to develop strong roots.
