In the City of Los Angeles, a tree planted in the parkway in front of a home doesn’t entirely belong to anyone. The homeowner is not allowed to remove it or even trim it in a manner the city deems improper, but is responsible for maintaining it and is legally on the hook if it wrecks the sidewalk or sewer pipes or topples onto people and things.
If deprived of water, trees tend to become diseased and unstable. If what’s around them is ground as hard as concrete or actual concrete, their roots disrupt pavement and sewer lines, which explains the predominance of broken sidewalks and pipes throughout the city.
Facing a lawsuit, the City of Los Angeles recently launched an aggressive $1.4 billion sidewalk repair program to fix its 11,000 miles of broken sidewalks and replace its root disrupting trees. The decision, in the short term, makes the City responsible for repairing sidewalks and planting new trees. But releases them from future liability and tree maintenance. After 3 years, homeowners are back to being personally responsible for what the city plants in the parkway, though the city may return for a one time repair and to prune trees over the years if funding allows.
Many homeowners are assured that the tree the city plants in front of their house won’t cause future root damage and will survive on its own after 3 to 5 years of watering. Of all the fictions that abound, none is as deceptive as that one. In truth, most trees, no matter the species, will eventually re-damage a repaired sidewalk or sewer line if they do not receive supplemental water throughout their life and if the soil is compacted. Not even winter rains offer much in the way of water for trees in hard soil parkways because the rain runs off far too quickly to build up a supply of water to last through our hot dry summers.
The city’s outdated planting practice of amending the soil in the planting hole is also problematic for the parkway trees. It seems logical that backfilling the planting hole with soft crumbly organic matter would improve the trees chances. And it does – in the beginning. But as young tree roots grow and encounter the interface between the planting hole and the hard native parkway soil, they react by circling the edge of the interface and growing back into the more hospitable fluffy environment of the amended planting hole. The roots do not establish, and therefore, they offer little in the way of support, eventually resulting in a toppling hazard in a wind or heavy rain event as canopy growth exceeds root ball diameter. Timber! As a last resort, some tree roots find their way to underground pipes surrounded by loose soil not fully compacted after construction. Here roots find room to breathe and grow.
At the end of the day, the lack of water and other stresses on the trees are so great that most of them die prematurely or are cut down for offending a sidewalk or underground pipe. Rinse repeat.