Let a Tree Grow in L.A.

Half of America’s street trees are missing.

Fifty percent of all our cities’ potential sites for street trees are vacant. And cities are planting only 27% of the trees needed to maintain the existing tree population. Los Angeles is better than average, but still lacks 31% of the street trees it could have. And the city’s tree budget is so low that most of the trees we do have are trimmed only once every 10 years.

What can be done about missing and neglected trees? The City Planning Department is considering an ingenious method to cultivate the urban forest: The city would require residential property owners to plant street trees at the curb before they sell their property. This proposal has several important advantages, for both the city and its property owners.

For single-family homes, studies have found that trees increase sale values by 3% to 19%, so the trees should more than pay for themselves. Nothing has to be done until the property is sold, and the sale would provide the cash to cover the cost of the trees, typically less than $200 each.

How long would it take for this plan to fill out the urban forests? In Los Angeles, half of all properties change ownership within 10 years, so planting at sale will affect neighborhoods quickly.

Paradoxically, this swift turnover suggests why there are so few trees in many areas. Many people do not own their property long enough to experience the benefits of planting trees. Therefore, few people will plant one unless the city pays for it or--as in this proposal--requires it.

Planting trees raises the question of who will maintain them. With the same reasons given for planting at sale, a city can require owners to have street trees trimmed at sale. Trimming at sale will shift onto property sellers some of the city’s maintenance costs, and will accelerate the frequency of trimming.

Trees are not a luxury or merely a middle-class concern. The poorest neighborhoods will gain the most, because they have the fewest trees. A recent survey of three low-income neighborhoods in Los Angeles asked residents what they would like to see more of, and the most frequent response was trees, well ahead of community services, parks and transit lines.

Many landowners would be willing to plant a single tree if they knew all their neighbors would do so too, but organizing the necessary cooperation has been difficult. Requiring trees at sale is a pragmatic, low-cost way to foster this cooperation.

In this simple way, a city can lead its property owners to promote their private interests by requiring them to promote the public interest when they leave.