Heartwood and Sapwood

Transfers

In wood anatomy, the distinction between heartwood and sapwood is fundamental to both the tree’s biology and the carpenter’s craft. Sapwood is the outer ring of living cells that actively transports water and nutrients from roots to canopy. As the tree grows, inner layers of sapwood die, their cells fill with resins, tannins, and other extractives, and they become heartwood — denser, darker, more durable, and structurally rigid. The heartwood no longer participates in the tree’s active metabolism, but it is what keeps the tree standing.

Key structural parallels:

• Dead tissue as structural backbone — heartwood is literally dead. It has stopped growing, stopped transporting, stopped adapting. But removing it would collapse the tree. This maps onto the core competencies, institutional knowledge, and proven processes that an organization relies on but no longer actively develops. The metaphor names the counterintuitive principle that the most load-bearing parts of a system may be the parts that have stopped changing.

• Living periphery as metabolic engine — sapwood is where the action is: water moves, sugars flow, new growth happens. It is also the most vulnerable layer — insects, fungi, and rot attack sapwood first. When organizations distinguish core from peripheral activities, the sapwood mapping highlights that peripheral activities (business development, experimentation, customer-facing adaptation) are both the growth engine and the attack surface. Cutting sapwood to protect heartwood starves the tree.

• Proportion determines viability — a healthy tree maintains a specific ratio of heartwood to sapwood appropriate to its species and environment. Too much heartwood relative to sapwood means insufficient nutrient transport; too much sapwood means structural weakness. The metaphor transfers the principle that the ratio of stable core to active periphery is itself a design parameter, not a fixed ideal. Different environments (fast-growing startups vs. mature firms) require different proportions.

• Grain and working properties differ — carpenters know that heartwood and sapwood behave differently under the blade. Heartwood is harder, more dimensionally stable, and more resistant to decay. Sapwood is softer, absorbs finish differently, and is more prone to warping. The metaphor warns that core and peripheral activities require different management approaches: the tools and techniques that maintain heartwood (documentation, standardization, compliance) are not the same ones that nurture sapwood (experimentation, flexibility, rapid iteration).

Limits

• Heartwood is dead; core competencies should not be — the most dangerous transfer from this metaphor is the implication that the core should be static. In a tree, heartwood’s death is permanent and beneficial — it frees resources for the sapwood. In organizations, a core competency that stops adapting becomes a core rigidity (Leonard-Barton’s term). Companies that treat their core as heartwood — unchangeable, load-bearing, finished — find that the environment changes around them while their core cannot respond. Kodak’s film chemistry expertise was heartwood that could not become sapwood again.

• The concentric model is too clean — in a tree, the boundary between heartwood and sapwood is a physical ring you can see in cross-section. In organizations, core and peripheral activities are not concentrically arranged. Customer support (seemingly peripheral) often generates the insights that reshape core product strategy. R&D (seemingly core) sometimes produces nothing of structural value. The metaphor’s clean geometry misleads about the messy topology of organizational knowledge flows.

• Trees do not choose their proportions — the heartwood-to-sapwood ratio is determined by species genetics and environmental conditions, not by the tree’s decisions. Organizations, by contrast, can and must deliberately allocate resources between core maintenance and peripheral growth. The metaphor naturalizes a ratio that should be a strategic choice, potentially leading managers to accept their current core/periphery balance as inevitable rather than designed.

• The metaphor privileges preservation over reinvention — because heartwood is valorized for its density and permanence, the metaphor subtly argues that the oldest, most established parts of an organization are the most valuable. This can discourage the kind of radical reinvention where an organization deliberately dissolves its heartwood to become a different kind of tree entirely.

Expressions

• “That’s heartwood — we don’t touch it” — protecting core systems or processes from change, framing stability as structural necessity
• “We need more sapwood” — arguing for investment in growth activities, experimentation, or customer-facing functions
• “All heartwood, no sapwood” — diagnosing an organization that has ossified, maintaining legacy systems while starving new growth
• “The sapwood is rotting” — warning that peripheral but vital functions (sales, support, developer relations) are deteriorating
• “You can tell by the grain” — the carpenter’s assertion that material properties are visible to those who know what to look for, transferred to organizational diagnostics

Origin Story

The heartwood/sapwood distinction is one of the first things taught in woodworking and forestry education. The terms themselves date to at least the 17th century in English, derived from the observable difference in color and density when a log is cross-cut. Carpenters have always known that heartwood and sapwood serve different purposes: heartwood for structural members, sapwood for applications where flexibility or absorbency matters.

The metaphorical application to organizations appears in management literature from the 1990s onward, particularly in discussions of core competency (Prahalad and Hamel, 1990) and core rigidity (Leonard-Barton, 1992). The heartwood/sapwood framing adds biological specificity to the otherwise abstract distinction between “core” and “periphery” — it names the mechanism by which cores form (accumulation and death of previously active tissue) and the consequence of losing the periphery (metabolic starvation).

References

• Hoadley, R. B. Understanding Wood (2000) — definitive reference on wood anatomy including heartwood/sapwood formation
• Prahalad, C. K. and Hamel, G. “The Core Competence of the Corporation,” Harvard Business Review (1990) — the management framework this metaphor enriches
• Leonard-Barton, D. “Core Capabilities and Core Rigidities,” Strategic Management Journal (1992) — the warning that heartwood can become pathological
• Schwarz, C. The Anarchist’s Tool Chest (2011) — practical carpentry perspective on working with different wood tissues