Four Ways Philly can grow its tree canopy

The City’s ambitious Tree Plan will need an all-out effort to accomplish. Here are some ideas we could steal from elsewhere.

Philly will get a ton of benefits if its first-ever Tree Plan succeeds.

Right now, our trees store 99,000 tons of carbon dioxide each year. That number will increase as the canopy grows. Our hottest neighborhoods — currently 22 degrees warmer than those with more tree coverage – could cool down, making it easier for residents to enjoy summer, lower utility costs and save $20 million per year due to the environmental benefits.

The plan would create 1,000 jobs. It could reduce crime by 12 percent because green streets are safer streets. It can also create wealth for residents: Homes with trees are between seven percent and 19 percent more valuable.

To reap these benefits, the plan needs to succeed, something the City’s past greening efforts have struggled to do. Other cities around the globe have successfully greened their streets with smarter planting, taking control of sidewalk plantings and paying residents to tend trees. Here are four ideas we could bring – or double down on – in Philly.

1. Plant trees in every available spot

New York has made headlines for its tree planting and tending efforts. In 2007, their parks department launched MillionTreesNYC — an effort to plant one million trees by 2017. They finished by 2015. They increased their canopy by two percent in recent years. Now, they’re trying to plant another million.

One way NYC is getting there: they don’t wait for resident requests or landlord permission to plant trees. Instead, if a tree pit is available, the City will plant a tree there. Here in Philly, our street trees are planted by request. Residents can contact the City for a free street tree or they can contact the Pennsylvania Horticultural Society (PHS) for up to three free trees. We don’t plant without the property owner’s permission, which has drawbacks. Renters, who make up 48 percent of the City, can’t request trees without convincing their landlords. 

NYC’s approach allows them to plant more trees, but it also allows them to offer more predictable customer service to residents. Before, the waiting list for trees by request was long. Planters had to move throughout the city. Now, they can take a more predictable block-by-block planting approach.

“We were finding that we weren’t able to respond to the service request with any sort of predictability. It was like we hear you, we want to get you a tree, and we will get there as soon as possible. But we weren’t providing a date,” says Jessica Einhorn, NYC Parks’ chief of forestry programs. “Now we can say, we hear you, we want to get your tree and we will be there in X year, and that’s determined by the map that we’ve put together.”

New York has just started this approach. They’re planting in the most heat-vulnerable neighborhoods first and plan to have a tree in every pit by 2027. They have a network of volunteers that help care for these street trees to help ensure their survival. (Einhorn says she’s been in touch with the Philly’s Parks team.)

Right now, Philly doesn’t have plans to plant street trees without resident permission. But they do engage in “opt-out” plantings, where Parks will plant trees in each available spot on a block unless a property owner refuses a tree. During opt-out plantings, Parks conducts outreach through letters and door-to-door visits to ensure that residents want trees and can properly water them for the first two years. Parks doesn’t have plans to plant without property owner permission, but they do want to grow opt-out planting efforts. They need more staff to help with this.

There are also efforts here to engage with landlords and property management companies to get trees in front of their buildings — which can span blocks — and around city properties, like public schools.

“We’re actually engaging property owners, property management companies and landlords, to make sure that we’re amplifying the voices of their tenants and saying, Hey, these folks live in these places where there are no trees. You’re a landlord. You’ve got six available pits. Can we plant some trees?” says  Dominique London, director of the nonprofit Tree Tender group UC Green. “And it’s working.”

2. Give trees a better chance to grow

Urban environments are punishing for trees. Concrete sidewalks prevent them from getting enough water. Their roots don’t have space to grow and they’re often not growing in the most nutritious soils. Cars hit them, causing structural damage. Then add in environmental factors like litter and dog pee and it makes it difficult for a newly planted tree to survive — much less reach the age where their branches and leaves are large enough to give shade and add to the tree canopy.

Even with these challenges, Philly has had success with its street trees. The average lifespan of our street trees is 19 to 28 years. That’s a lot better than the average in other cities, which is between seven and 13 years.

Still, whatever we can do to improve the chances of street tree survival helps our canopy. Stockholm has somewhat solved for these problems. Their planting method involves digging pits that are 500 square feet and are filled with 3- to 5-inch-diameter stones, compost and biochar, a carbon-rich material. This mix aerates the soil, allowing water to get through and roots to grow, while being strong enough to support the concrete above. Trees planted using this method grew from 30-35 centimeters to 70-83 centimeters between 2004 and 2013.

Now, U.S. cities — and others worldwide — are using this method. Montpelier, Vermont, started the process with four newly planted trees in 2021. One of the trees they planted using the method grew 42 inches in one year.

“[Before,] you’d plant the tree, five years later, it dies, and you take it out, and you see the roots have not expanded at all,” says Alec Ellsworth, parks director and tree warden, for Montpelier. “What we’re trying to do is create better subsurface conditions for tree roots to spread.”

Ellsworth says it costs about $10,000 per tree, but about $7,000 of that is fixed costs like creating the pits and putting iron grates around them. The iron grates are not essential to the method, however. Montpelier uses them to maintain ADA compliance with their sidewalks. Philly Parks and Rec estimates it will cost around $71,000 to plant the 90 trees on the street tree waitlist.

When people request a free street tree from the City, they’re responsible for making sure that they already have a tree pit and that any stumps from dead trees have been removed. If you request a free street tree from PHS, they’ll have a contractor come cut a pit for you. Residents are still responsible for removing stumps. London says the cost of having a tree pit cut can range from $250 to $300.

3. Pay residents to tend trees

Amongst the Philly Tree Plan’s many goals are hiring urban forest community organizers in the short term, hiring more Parks and Rec arborists and street tree inspectors in the mid-term, providing stipends for volunteers, expanding same-day work and resident employment programs and expanding paid community tree care programs.

In other words: we should pay the people who are planting and caring for our trees. We have some job training programs for this, notably Power Corps PHL, which trains people to work in urban forestry, but there’s more we could do.

After losing trees to deforestation for decades, Freetown, Sierra Leone, started paying its residents to grow and care for trees. Using a digital platform, residents can sign up to plant, tag and tend trees. They fund the program with tokens sold on carbon markets — basically when a person or a company buys a carbon offset, they could purchase one that supports these plantings. So far, the program has reforested around 2,500 acres and created more than 1,000 jobs.  

“The City of Freetown creatively tackled a widespread problem—deforestation—with a solution that both improves its environment and expands economic development,” says Aparna Ramanan, leader of the Bloomberg Philanthropies Mayors Challenge program, which supported Freetown’s efforts when they won in 2021.

There might be potential for an application like this to exist in Philly through a public-private partnership. The Philly company Glitter uses a similar, app-based approach to cleaning up litter in the City. Neighbors can purchase a subscription to have their block cleaned and Glitter workers will clean them. A digital platform helps manage everything. Some blocks have their Glitter cleanings funded by grants and government support programs. Maybe we could do something similar for trees? Our Tree Fund law already requires developers to pay fees when they cut down trees and that money is intended to be used to help implement the tree plan.

4. Make sure the Tree Plan doesn’t lose its way

It’s always good to look to other cities for innovative ideas, but experts say that if Philly achieves all of the goals set out in the Tree Plan and actually equitably increases its tree canopy that will be a feat. We need to ensure the Tree Plan remains a continuous funding and policy priority.

“I’m sometimes hesitant to apply one policy that was effective in one city to a city like Philadelphia, because I think it’s unique,” says Hamil Pearsall, professor of geography, environment and urban studies at Temple. “The Philly Tree Plan is very progressive, and it could potentially become a model for cities around the country.”

Other cities, like New York, are already taking steps to craft similar plans of their own. Einhorn says they’re working on the City’s first urban forestry plan. The goals — and the process — are similar to Philly’s: equitably increasing canopy, working with property owners, city agencies and community stakeholders to achieve planting and tending goals. The first plan will last 10 years and it will be revisited at that time to ensure the city makes progress.

“It’s not just Parks’ jurisdiction,” Einhorn says. “I’ve been working hard with the mayor’s office of environmental justice.”

To make sure the Tree Plan stays on track, the partners have created the Philly Tree Coalition, an organization, housed within PHS, that will help with long-term planning and fundraising from both public and private sources so we can implement the plan. They’ll also work to foster collaboration amongst the Tree Plan’s many partners.

A steering committee comprised of PHS and various city agencies, including Philadelphia Parks and Recreation, Public Health Management Corporation (PHMC), the School District of Philadelphia, Fairmount Park Conservancy, the Sustainable Business Network of Greater Philadelphia and PowerCorpsPHL will lead the coalition. The director of the Philly Tree Coalition will be an employee of PHS.

PHS says they’re in the final stages of interviewing candidates and deliberating with partners to hire the director of the Philly Tree Coalition. They do not have a date for when the announcement will be made at this time. 

Cover photo: Claudia Salvato Photography

This article is published in collaboration with the Philadelphia Citizen as part of a project series for the Philadelphia Journalism Collaborative.