Street tree abuse – Part 1

Street tree abuse is all too common in many cities. Here, a tree was planted to high, leaving its roots exposed on the surface. This would not be a serious problem – it is better to plant too high than too low – if it weren’t for subsequent damage by mowers. Every exposed root of this tree is severely damaged. The tree is unlikely to survive for long.

street tree

Improperly planted red maple with root ball above the ground level.

Poor practices in street tree planting and maintenance are costly. The cost of planting to the city for planting a street tree, including purchase of the tree and labor and material for preparing the site and planting the tree, is around $800 in Lexington, KY, where this tree is located. The benefits of a street tree are well known and quantifiable: increase in real estate value, reduced house energy costs, improved air and water quality, and carbon storage. It takes 10 to 20 years for the cumulative benefits of the tree to exceed the cost of planting. So, when a tree is improperly planted and does not live to a reasonable size and age, its net benefits (benefits-planting cost) are less than zero – the tree is a liability.

street tree

Chronic mower damage of the woody roots of the red maple.

If we assume that half the street trees in our city are improperly planted or maintained, it is difficult to make a case that they are worth the cost. The only reasonable solution is to improve tree planting and management, and to include tree maintenance in the planting budget. There is no reason whey many street trees cannot live long enough to recoup their planting costs, but only if our current practices change.

street tree

Upper surface of root damaged by mower, bark on lower surface cracked due to bending stress (e.g. from stepping on it or rolling a trash cart over it).

Woody roots grew out from the root ball to anchor the tree. Without chronic mower damage, the tree would survive incorrect planting.



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