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Community members planting trees. Photo credit: Alex Indigo, CC BY 3.0 DEED
What is an Urban Heat Island?
Cities are really, really hot! Picture this: you are walking across a parking lot downtown in the summer. The sun is out, there is barely a breeze, and you are feeling the heat. That heat isn’t just from the sun! It radiates from all the concrete of the roads, sidewalks, and buildings around you. Then, you see a park with large canopy trees shading the walkway; maybe walking through it will provide some relief. As you enter the park, you can feel cooler temperatures wash over you - more than just from escaping the sun. In fact, trees can lower air temperatures underneath their canopy by 20–45°F through shading and an additional 2–9°F by moving water up through their roots and releasing it through their leaves through a process called evapotranspiration. This can make a big difference in cities, which experience higher temperatures because of all the concrete and asphalt surfaces. These hotter temperatures in cities are part of what is called the urban heat island effect, and it can cause adverse health impacts for residents. Trees are one answer to this problem.
Street and median strip trees growing in downtown Baltimore, Maryland. These trees provide cooling benefits! Photo: K. Burghardt
Trees in cities also do other essential things for residents. They take up stormwater to reduce flooding, prevent erosion, and improve residents' mental health and well-being. They can provide habitat for birds and pollinators! Read more about the benefits of planting trees and considerations for climate change here.
Unfortunately, tree cover is rarely equally distributed across city neighborhoods. Many places within Maryland cities need more trees to approach the canopy cover goal of 30-40% cover, which will provide maximum cooling benefits.
The urban trees grant program
The Maryland General Assembly passed historic legislation HB 991 during its 2021 session.
The bill establishes that it is the policy of the State to support and encourage public and private tree-planting efforts, with the goal of planting and helping to maintain 5 million sustainable native trees in the State by the end of calendar 2031
It also stipulates that at least 500,000 of those trees be planted in an “underserved area,” defined as an urban area as delineated by the US Census Bureau that also meets one or more of the following criteria:
Historic disenfranchisement: A neighborhood that was, at any point in time, redlined or graded as “hazardous” by the Home Owners’ Loan Corporation; OR
Unemployment: A census tract with an average rate of unemployment for the most recent 24-month period for which data are available that exceeds the average rate of unemployment for the state; OR
Household income: A census tract with a median household income for the most recent 24-month period for which data are available that is equal to or less than 75% of the median household income for the state of Maryland during that period; OR
Housing project: A housing project as defined in Section 12-101 of the Housing and Community Development Article.
The Chesapeake Bay Trust (those “Save the Bay” license plate folks) runs the grant program for the State of Maryland. You can find the request for proposals (pdf) and explore the portal to apply here. Applications can be for planting and maintaining any number of trees from 25 to 6,000. Community groups, churches, and non-profit organizations are all eligible to apply.
This is a fantastic opportunity if you have a corner, vacant lot, park, church, community space, or even private property where adding trees would enhance the neighborhood for all!
Is my community eligible to apply?
The state has put together a handy interactive map where you can search your address and see if your community qualifies for the program. We’ve added a screenshot from the site below, but you can zoom into your neighborhood from the website.
The orange neighborhoods above are the urban areas in Maryland eligible to apply for money to plant trees through the Urban Trees Grant Program. Photo credit: Maryland DNR
How do I know what trees to plant?
Chesapeake Bay Trust provides substantial guidance on its website. One key idea is that when you choose the trees you want to plant, try to choose many different tree species for your neighborhood rather than just choosing one. By choosing a variety of tree species, you are following the diversification principle of Integrated Pest Management (IPM), which means it is less likely that the entire tree canopy will be damaged or killed when a pest or disease inevitably arrives. In other words, you will still have a tree canopy that benefits residents! This is becoming increasingly important as cities lose trees to introduced pests like the Emerald Ash borer, which has been attacking and killing ash trees all over the eastern half of the United States. Communities that planted all ash trees in the past now have more significant expenses - and many trees to replant.
To make selecting tree species easier, our lab, working on behalf of the University of Maryland Extension (UME), put together an interactive list of eligible Maryland native tree species for planters. These species are known to do well in various challenging urban conditions, and there is a lot of information to allow you to put the right tree in the right place. You can choose trees based on fall leaf color, flowers, habitat for pollinators, edibility for humans, and more! We can’t wait to see what you pick!
Screenshot of a downloadable interactive tree species selector tool for choosing trees to plant in urban areas of Maryland.