Street trees beautify a neighborhood. Few would argue that it’s more enjoyable to walk down a tree-lined boulevard than a concrete corridor. On Friday, April 27 we celebrate Arbor Day, and it’s a great time to consider planting a tree in front of your home. And with the passage of Proposition E in San Francisco in 2016, care of street trees reverted back to the city government.
When Native Americans inhabited what is now San Francisco, the landscape consisted of large swaths of grasslands, sand dunes, and salt marshes, with only six species of trees and three types of bushes that can grow to tree size. More species of trees were eventually introduced to Mission Dolores, and after the Gold Rush there were between 400 and 500 tree species in the area. That number is now more than 500. San Francisco’s tree canopy is at approximately 13.4 percent, which is actually quite low compared to many other cities. There are approximately 669,000 trees in the city, with the most common being the London plane tree (you’ll recognize these as the distinctive trees at the Civic Center), the Indian laurel fig, and the New Zealand Christmas tree. Of the total trees, about 125,000 line the streets of San Francisco, with the rest being in backyards and parks.
Besides the obvious aesthetic quality trees bring to a neighborhood, there are a plethora of additional benefits. Street trees increase the curb appeal of a house, therefore increasing the property value. A study of home sales in Portland, Ore., found that on average, street trees add 3 percent to the median sale price of a house. Traffic noise is absorbed and trees create a sense of privacy.
Trees produce oxygen, clean the air, and reduce global warming. Two medium-sized, healthy trees can supply the oxygen required for a single person for a year. By absorbing greenhouse gases, trees clean the air by storing carbon dioxide in their stems and leaves. Airborne particles such as dirt, soot, and dust are also captured by trees.
Sidewalk gardens and trees reduce flooding by capturing rain. During heavy rainstorms, large amounts of water can overload the city’s combined storm-sewer system, causing polluted runoff containing dangerous chemicals into the street to get dumped in the bay. A mature tree can store 50 to 100 gallons of water during large storms. The average tree in San Francisco can intercept more than 1,000 gallons of rainwater a year.
The presence of trees has a calming effect on traffic, reducing the speed of drivers. Trees and sidewalk gardens increase revenues in shopping districts, with some studies showing consumers have a 12 percent higher willingness to pay for goods and services in retail areas with streetscaping. Street trees also provide a natural habitat for birds and insects.
Are you interested in getting a tree planted in front of your home? Friends of the Urban Forest (FUF) makes it easy and affordable for San Franciscans to get new trees in front of their properties. They pay most of the costs and even offer a limited number of free trees.
When you sign up for a tree, FUF will provide these services: Check utilities to ensure no interference; cut and dispose of concrete from the sidewalk; species recommendations by their arborist; the tree itself; hardware to support and protect the tree; a volunteer crew to help with the planting; new tree owner’s manual; and three years of tree care service.
The only thing you have to do is to commit to watering the tree for the first three years. FUF will plant trees in any San Francisco neighborhood where at least 30 trees are requested. Plantings are community events that include neighborhood residents, volunteers, and FUF staff. Most of the tree planting costs are covered by grants and donations, with property owners making a co-payment on a sliding scale.
Sidewalk garden landscaping projects are smaller scale and require just 8–10 homeowners on a block requesting greenscaping. A typical FUF garden includes California native and drought-tolerant plants, giving the garden a great chance at survival.
If you are interested in learning more about the urban forest of San Francisco or would like to volunteer to lead tree or sidewalk garden plantings, consider taking the Friends of the Urban Forest Community Forester training program. The six-week program is designed to help individuals become the best volunteer arborist possible.
Topics include San Francisco ecology and street tree identification, proper tree planting procedures, street tree biology and structural pruning, fruit tree biology and structural pruning, community advocacy and volunteer leadership, and plant data collection with citizen science projects. Classroom lectures take place Wednesday evenings in FUF’s office in the Presidio, and each lesson is accompanied by a field session the following Saturday morning.
Visit fuf.net to request a tree or street garden or for further information on Friends of the Urban Forest.