The Princeton Shade Tree Commission serves to protect and manage our community forest and shade trees. Trees and shrubs are a natural resource that provide aesthetic, economic, ecological, environmental, and health benefits to the municipality of Princeton and its inhabitants. The treatment of trees and shrubs on individual properties can have significant impact not only on those individual properties but also on neighboring properties, the streetscape, the tree canopy, and the entire municipality. Princeton’s trees and shrubs ordinance establishes rules and regulations for the stewardship of this resource within Princeton, on both public and private property.

(NOTE: The Princeton trees and shrubs ordinance currently accessible on this website was revised and strengthened in 2016 and is now in effect. It will be added to this website when the codified version becomes available. In addition, an amendment concerning management of ash trees on private property was added to the ordinance. This amendment concerning ash trees is now in effect and can be linked to from the menu on the left-hand side of this website.)

Pest Alert

The Emerald Ash Borer (EAB), a non-native insect pest that kills all species of Ash trees, has now been found in Princeton as well as in surrounding counties. This highly destructive insect has killed millions of Ash trees in Michigan, where it was first found in 2002, and has killed tens of millions of additional trees in the twenty-three other infested states and two Canadian provinces. Princeton is currently formulating an EAB management plan for its approximately 2,000 Ash street trees.

The NJDEP State Forestry Services recommends:

  • IDENTIFY Ash trees. Ash species have opposite branches and leaves and a compound leaf with 5-11 leaflets. The bark on older trees has a unique diamond-shaped ridge bark, but younger trees may have smoother bark. Click here for images of an Ash tree and Ash tree look-alikes. 
  • MONITOR your Ash trees for the Emerald Ash Borer. You will know when the risk of mortality becomes urgent. Look for dying branches at the top of the tree, woodpecker damage, galleries under the bark, d-shaped holes, bark splits, sprouting at tree base and along trunk, and green adult beetles.
  • USE TRAPS to detect the Emerald Ash Borer in your community or woodlot. If the Emerald Ash Borer is in the area, it will be attracted to these purple prism traps.
  • SPREAD THE MESSAGE: DON'T MOVE FIREWOOD. Visitors who bring infested firewood to second homes or campgrounds near you put your trees at risk. Use only locally sourced or certified firewood.  (More information on firewood.) 

To determine the health of your Ash trees, consult Assess Ash Trees for Emerald Ash Borer.

Click here  To view the STC criteria that will help you decide whether to remove an ash tree or treat it.

Click here  To consult the Managing Emerald Ash Borer Decision Guide for treatment options.  

Click here   For a list of certified tree experts in Mercer County. Following the list is a key to the final column, labeled "services."

Click here  For FAQs regarding potential side effects of EAB insecticides.

Click here  To view the 2016 amendment to the Princeton Trees and Shrubs ordinance that exempts ash trees from some requirements of tree removal permits. 

Click here  To watch the STC's June 23, 2016, public information session on the Emerald Ash Borer, videotaped by and courtesy of Princeton TV.

Click here  To view an interactive map of municipal Ash trees in Princeton.

For more information, the following websites are helpful:


Arbor Day

In Princeton, we usually combine our Arbor Day celebration with Communiversity, the outdoor festival which generally falls each year on the last Sunday in April, from 1 to 6 pm. In 2017, Communiversitywill take place on Sunday, April 30, from 1 to 6 pm.

We hope you stop by our booth on April 30, where we will once again be distributing information and answering questions about trees and their care.

Our Arbor Day traditional community tree planting will take place at Princeton elementary schools on Tuesday, April 18 (Princeton Charter School), Thursday April 20th (Littlebrook School), Thursday April 27 (Community Park School), and Friday, April 28 (Johnson Park School). Princeton's arborist, Lorraine Konopka, will talk to third graders about how trees are planted and maintained.

This year we will be handing out Eastern redbud saplings.

The Easter redbud (Cercis canadensis) is a medium-size tree which grows along the edges of woodlands and forests where it stretches towards the sunlight often becoming irregularly shaped and leaning with age.  The tree is native to the Eastern and Midwestern United States. The Eastern redbud has pink-lavender flowers, prominently displayed in April before the foliage emerges. The tree has alternate heart-shaped leaves and flattened green pods that occur in clusters on the twigs.