Caring for Ash Trees/Managing Forests

Long term management of emerald ash borer in New Hampshire involves actions by homeowners, forest landowners, communities, and state and federal agencies.

Ash Tree Treatment Options

A licensed pesticide applicator can be hired to treat your ash trees.  When seeking the help of an arborist, you can ask if they are licensed by State of NH Division of Pesticide Control or contact the State of NH Division of Pesticide Control at (603) 271-3550  to find licensed applicators in your area. Resources for selecting an arborist in NH and a link to the NH Arborists Association can be found by clicking below.

VISIT NH DIVISION OF PESTICIDE CONTROL
Find an Arborist
Tree Work Contract
Selecting Trees for EAB Treatments

Management zones, based on current known infestations, are established for all of New Hampshire.

Know your zone. See map.

  • Generally infested area - PINK zone
  • Potential expansion area (within 10 miles of the infestation)- WHITE zone

Inventory your trees by species, size and value.

Evaluate ash trees for signs of EAB. Report suspect trees or insects.

Generally infested area - PINK zone

Landscape Trees

  1. You may remove all known infested trees near structures, cars and roads.
  2. Consider insecticide treatment for high-value ash. Ask three licensed pesticide applicators for quotes.
  3. Consider removing remaining ash trees while they’re still healthy—dying ash can be hazardous to remove.
  4. Use the material locally and follow best management practices when transporting logs.

Trees in natural settings

  1. When a stand is being harvested, cut all large ash. Encourage small sizes under 4 inches in diameters. Protect and encourage ash regeneration.
  2. Identify several large, mature ash in pairs of a male and female as a seed source. Treat with pesticide every three years using a licensed applicator.
  3. If the harvest area isn't heavily infested, girdle 20 to 30 sawlog-size ash in advance of the timber sale. These trap trees will attract egg-laying adults and the larvae will be destroyed when the trees are harvested. Girdle using hand tools in the early spring before the scheduled harvest.
  4. Follow best management practices when transporting logs. Consult the Legal transportation of ash wood products from NH & VT to ME, if moving ash into those states.

Potential expansion area - WHITE zone

Landscape Trees

  1. Consider removing ash trees while they’re still healthy—dying ash can be hazardous to remove. 
  2. Consider insecticide treatment for high-value ash. Ask three licensed pesticide applicators for quotes.
  3. Identify large, healthy ash trees and monitor them for signs of EAB regularly.

Trees in natural settings

  1. Identify forests with high volume ash and monitor.
  2. Harvest ash only during regularly scheduled management
  3. During regularly scheduled harvests, remove large diameter ash leaving small amounts of small diameter ash.

Management Zones

emerald ash borer map

PINK - Generally infested area
Emerald ash borer is in this zone, though not necessarily in all ash trees.

WHITE - Potential expansion area
Emerald ash borer isn't known to be in the area, but the area is within 10 miles of the outer limits of the known infestation. There is a high probability emerald ash borer will spread naturally to this zone within a few years.

Definitions

Diameter at breast height (DBH)- Diameter of a tree at 4.5 feet above the ground

High-value ash- A tree valued for economic, ecological, aesthetic or cultural reasons.

Trap tree- A low-valued ash girdled to attract EAB and monitored by the N.H. Division of Forests & Lands.