Environmental Threats

The Department of Public Works Parks & Greenery Division is responsible for caring for the parks, recreational areas and natural environment within city limits. This includes the 10,000+ trees in Portsmouth's urban forest.

Caring for the urban forest includes pruning, treating injured trees, removing trees as directed by the vote of the Trees & Public Greenery Committee and an ongoing program of planting new trees each year. The Arbor Day Foundation has awarded its Tree City Award to Portsmouth for more than 20 consecutive years and has also identified Portsmouth as one of its distinctive Tree Growth Award cities.

The ongoing efforts of the City Arborist and the Parks & Public Greenery Team mean Portsmouth residents enjoy the benefits of their urban forest: a green canopy, shade (reducing summer energy costs), recreational opportunities in beautiful surroundings and a habitat for song birds and other wildlife.

These benefits require vigilant attention to the dangers of storm-damaged trees or those at risk of interfering with electrical wires, invasive species and diseases.

Current concerns include:

• Emerald Ash Borer -- 

  Emerald Ash Borer (EAB) is an invasive pest originating in Asia and was first observed in NH in Concord in 2013. The EAB was discovered in Portsmouth in spring 2023. All ash trees are at risk and most City-owned trees will be removed before they become a risk to public safety.  

  Residents who own an ash tree should treat or remove it before it becomes a hazard, as limbs become weak and break off, causing damage, injury or even death. After removing an ash tree or tree limbs, please dispose of the wood only at the City Recycling Center (680 Peverly Hill Road) to limit the spread of EAB. For more information, call 603.427.1530.
• Asian Longhorned Beetle
• Hemlock Wooly Adelgid
• Gypsy Moth ("Spongy Moth") Caterpillars

Additional resources:

UNH Extension Invasive Plants & Pests

​​​​​​​NHBugs.org