Heritage canopy. Concerning surface defects. The decision runs through the resistograph.
Haddonfield is one of the storied tree towns of South Jersey. Camden County borough, designated arboretum status, heritage canopy along Tanner Street and around the historic district that some of the residents have known since childhood. When a heritage oak in Haddonfield shows surface defects that worry the property owner, the conversation isn’t casual.
View from the Field · Haddonfield NJ · Tree Awareness
The borough sits at the heart of one of the most tree-aware municipal regions in the state. Haddonfield’s street-tree program, the historic district’s heritage canopy, and the residents’ long-standing relationship with named individual specimens all push toward keeping mature trees on the landscape whenever it’s safe to do so.
It also matters that Haddonfield’s street and yard trees are predominantly mature hardwoods — oaks, maples, sycamores. Species that compartmentalize wounds aggressively, that often hold structural integrity past what visible symptoms might suggest, and that reward the resistograph protocol because the data picture inside the wood is often better than the surface picture predicts.
Visual reading first. The surface symptoms drive the targeted assessment. Where on the trunk is the suspected decay? What does the bark look like? Are there indicator fungi? Is the root flare normal?
Sounding. Hammer or mallet against the trunk. The tone tells you what’s under the bark — solid wood vs. detached bark vs. internal cavity.
Targeted bark exploration. Where the sounding suggests a problem, gentle bark removal to see what’s underneath. Live cambial tissue inside what looked like a decay zone is a major positive signal — the tree’s compartmentalization machinery is working.
Resistograph drilling. The data-grade examination. A small drill bit advances into the wood and the resistance gets logged across the depth of the bore. Solid wood reads high. Decayed wood reads low. Voids read near-zero.
Baseline and re-assessment. Photographs of the wound. Measurements. Resistograph traces filed. The tree gets a follow-up visit on a defined cadence.
The pattern that often shows up on a properly-functioning hardwood: surface decay limited to the outer few inches, with progressively more solid wood behind it as the bit advances inward. The tree had been compartmentalizing the wound for years — building barrier walls of denser, chemically defended wood inside, isolating the decay from the structural cross-section.
The arboricultural literature has a name for this: CODIT (Compartmentalization of Decay in Trees). Mature oaks are particularly good at it. The visible decay on the surface is often a fraction of what the tree has functionally walled off.
For this Haddonfield oak: keep, monitor, prune for safety, re-assess in 12 months. Not what the surface visual suggested at first glance — but what the data, properly collected, supported.
The flip side is the case where the resistograph reveals the problem is worse than the surface suggested. On those trees the data justifies the removal call that the visual evaluation might have missed. Both directions matter.
Heritage trees are not replaceable on a human timescale. A 200-year-old oak that comes down can’t be re-grown in 50 years. Every heritage specimen we keep standing through proper assessment and proper care is canopy that the next two generations of property owners will live under.
The protocol Paul walks in this video is the work that justifies keeping trees. It’s also the work that justifies removing them when removal is genuinely the right call. Either direction is defensible when the data supports it.
For TRAQ + resistograph on a heritage tree in your part of South Jersey, request a Tree Risk Assessment →
