Here’s a look inside SF’s urban forest plan as it works toward planting 3,500 trees over 5 years

SAN FRANCISCO (KGO) — Nearly two years ago, ABC7 News told you about a comprehensive project to add trees in San Francisco streets.

The city, which has one of the smallest urban tree canopies among big cities, set a goal to plant 3,500 trees over five years. We checked in to see what the progress was for this project.

On a foggy, cold San Francisco day, tree planting crews were placing an olive tree in its designated location.

“OK, we’ll get the ladder there and let’s get the stakes,” said Leo Torres, instructing the three-man crew from the San Francisco Department of Public Works.

You think planting a tree would be a simple process. But, it takes more than just digging a hole and sticking the tree in the ground.

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First, you know what they say about location, location, location.

“We want the more bare side to go toward the sidewalk, because we want the tree to grow out. We don’t want it to necessarily grow into the sidewalk, because then it protrudes as pedestrians walk by. And what this is, once we water the tree since it’s so young, it keeps the water in the berm here,” Torres said.

Stakes around the tree provide stability, especially when it’s windy.

“This is called the gator bag. It takes 20 gallons of water,” Torres said.

From this moment on, regular maintenance done by Public Works crews is essential.

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This newly planted olive tree now located in the Mission District is ready to face both people and the elements. The Mission District is known for its sunny and warmer climate, so, in this case an olive tree is fitting.

“I choose an individual species based on the site location, the width of the path of travel, all those sorts of things,” said Alegra Mautner, an arborist with SF Public Works.

Each tree is thoughtfully selected and planted based on San Francisco’s micro climates.

“I have developed a spreadsheet that I use that has about 150 different species on it, and I have about 50 columns on it. So, based on the light requirement, is it on the North side of a building where you get a lot of shade or so you need certain species to be able to be tolerate of the shade. Does it get a lot of wind, do you have sandy soil or clay soil? These are the things that are very site specific in San Francisco,” said Mautner as she gives us a tour of the Public Works nursey.

San Francisco is expected to plant 3,500 trees within five years to improve its tree canopy, which covers only 13.7% of the city. The national average is just over 27%. A $12 million federal grant will help plant trees in neighborhoods like the Mission, Tenderloin, the south of Market area and the Bayview-Hunters Point District, where temperatures tend to be higher because of the lack of trees and green spaces.

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To meet the 3,500 goal, DPW would have to plant 700 trees a year.

“So, in the first year we’ve completed 250 trees in San Francisco, and we’ll finish those by about the end of June, and then the next year we’re standing with 1,250 trees,” said Jon Swae with Public Works.

It begs the question, why does a city so environmentally concerned have so few mature trees?

“Our landscape is mostly sand dunes and scrub vegetation with just a few trees and also we have a very built out urban environment. So, where in other cities you have buildings that are set back from the sidewalks, in San Francisco, our buildings are all close together and come right out to the sidewalk, so there is less room for trees,” Swae said.

DPW admits it’s real goal is to plant an ambitious 30,000 new trees by 2040, adding greenery along medians and every sidewalk in the city.

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“Our work will not be done. We will need to maintain trees, and we do occasionally — reluctantly — have to remove trees. And so, we’ll continue to replace trees that get removed. But, if we can get to that additional 30,000 trees, we will be at about 155,000 street trees, and that should represent full stocking for us,” said DPW Director Carla Short.

The source of that funding is anyone’s guess. But, one advantage Public Works has is this nursery under the freeway, near the Bay Bridge. It’s being leased from Caltrans. It’s a staging area where DPW grows trees and allows those newly arrived saplings from the Central Valley to acclimatize to San Francisco’s harsher climate.

By the way, anyone in San Francisco can request a tree be planted in front of where they live.

“You don’t have to own property to get a tree planted in the front of your building, because the right of way in San Francisco is owned by San Francisco, so it’s a public benefit for all of us,” Swae said.