December 2025 Newsletter

Contents

  1. Cambridge’s Newest Canopy Report Now Available! 
  2. Store Gator Bags for Winter 
  3. Holiday Trees Around Cambridge 
  4. Species Highlight: American sweetgum 
  5. Stumped! Urban Forestry Treevia 
  6. Become a Cambridge Urban Forest Friend   
  7. Sign Up for a Tree with Green Cambridge   

Cambridge’s Newest Canopy Report Now Available! 

Public Works is excited to share the latest update to the City’s tree canopy assessment! The assessment was prepared by the University of Vermont’s Spatial Analysis Lab and analyzes changes to the tree canopy from 2018 through 2024. Our canopy experienced both loss and gains with an overall increase in Cambridge’s canopy by 5% from 2018 to 2024! 


The canopy report uses aerial imagery and LiDAR (Light Detecting And Ranging) data captured from airplane flyovers to determine canopy coverage and changes. Improved techniques in LiDAR refinement and harmonization have increased the accuracy of recently collected LiDAR data as well as data from past years.   


Canopy growth resulted from a combination of preservation of existing mature trees and their yearly growth as well as new plantings. Continued targeted plantings and protection of mature trees will help keep this positive trend going. Together we can support a thriving, resilient, and diverse urban forest.  


To view the Canopy Report online, please click here.

Excerpt from the newest canopy report showing an overall increase in tree canopy.

 

Store Gator Bags for Winter

As temperatures drop and the ground begins to freeze, trees enter dormancy and no longer need regular watering until spring. If you’ve been watering your tree (thank you!!) and it has a gator bag, now is a great time to remove it and store it for the winter. 


Leaving gator bags on during extreme winter weather can cause them to deteriorate. Over longer periods, bags left in place can even harm trees by trapping moisture against the trunk, which may lead to decay or trunk damage as the tree grows. 


Early winter is the perfect time to remove the bag, check it for large tears or holes, and save it for reuse next spring. 


Holiday Trees Around Cambridge


Have you spotted the holiday trees lighting up Cambridge? Public Works Urban Forestry crews and the Electrical Division recently installed and lit festive trees across the city. You can find them at: 


  • Public Works Main Office, 147 Hampshire St (pictured below) 
  • Police Station Island at Western Ave & River St 
  • Charles Sumner Statue at Mass Ave & Garden St 
  • DeGuglielmo Plaza at Brattle Square 
  • Porter Square Shopping Center 


Be sure to check them out while you’re out and about this season! 

Holiday tree at Cambridge Public Works

 

Species Highlight: American sweetgum (Liquidambar styraciflua) 

Stars are a common symbol this time of year, and sweetgum trees are full of them during the growing season. Their five-lobed, star-shaped leaves are easy to recognize and truly shine in fall. Sweetgum foliage can display a stunning mix of yellow, red, orange, and purple, sometimes all on the same tree, with colors varying from year to year. 


Sweetgums often hold their leaves later than other deciduous trees, which can increase the risk of damage from early snow and ice, especially when planted north of their native range. Their spiky, ball-shaped fruit is another notable trait, though cultivars such as ‘Happidaze,’ ‘Cherokee,’ and ‘Moraine’ are cold-hardy and produce fewer fruits. 



At maturity, American sweetgums can reach up to 60 feet tall and develop a neatly pyramidal crown, making them a striking addition to the urban forest. 



Cambridge has many beloved sweetgums, is there one near you? Check out our species map to find some in your neighborhood here.


A close up of colorful fall sweetgum foliage at Russell Field

Sweetgum Fruit

A mature sweetgum on Holworthy St.

Stumped! Urban Forestry Treevia


Learn a fun fact about urban forestry in Cambridge! 

How does salt affect trees?

The trivia answer will be revealed in next month’s newsletter! 


Last month's question was "Ginkgo trees have existed as a species, virtually unchanged, for how many years?” and the answer was "D. 200 million years". Did you get it right?  

Become a Cambridge Urban Forest Friend

We need your help to maintain a healthy, vibrant urban forest! Any Cambridge resident willing to regularly water the tree and provide some general care for the tree is welcome to become a Cambridge Urban Forest Friend.


How to Start

Questions?


For questions about the Cambridge Urban Forest Friends, please contact Kristen Kelleher, Community Relations Manager at 617-349-4825 / kkelleher@cambridgema.gov.


**Please let us know if you are no longer caring for your street tree and we will remove you from the database and future emails.**

 

Sign up for a tree with Green Cambridge

If you have space for a tree on your property, Green Cambridge can plant a tree to help expand Cambridge’s urban tree canopy! If you own your home in Cambridge, MA and would like Green Cambridge to plant a tree in your yard, visit https://www.greencambridge.org/canopycrew

Thanks for reading! 


If you enjoy the Cambridge Urban Forest Friends newsletter, you can spread the word about it with this sign-up link. With more sign-ups, more Cambridge residents can learn about how to best support our environment and communities.


To receive this newsletter in English, email Cambridgetrees@cambridgema.gov


Para recibir este boletín en español, envíe un correo electrónico a Cambridgetrees@cambridgema.gov


Pou resevwa bilten sa a an kreyòl ayisyen, voye yon imèl bay Cambridgetrees@cambridgema.gov


 
 
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