Mature Carrotwood Slime Flux: Arborist Drilling Plan Questioned

Case

40-yr-old carrotwood (LA): black sap oozing from conical hole 2 ft out on major limb. Arborist: slime flux, drill vertically through limb to dry it. Owner approved. Asks if correct.

Expert Validation

• Certified arborist + seen tree = trust his assessment.
• Symptoms match slime flux (wetwood): bacterial fermentation → gas pressure → sap flux.
• Carrotwood = known slime flux host.

Slime Flux Science

• Bacteria enter wound → create anaerobic, high-pH wood (wetwood).
• Wetwood = defense against decay fungi (undesirable pH for them).
• Fermentation → methane → pressure → sap oozes.
• Sap darkens, may smell (yeast), attracts insects.
• Won't kill tree. Longevity depends on original injury extent + stress.

Drilling Controversy

Modern arboriculture: drilling/drain tubes outdated. Risks: spreads bacteria, creates new wounds for decay fungi. Better: monitor, maintain vigor, flush with water if odor/insects problematic.

Follow-Up: Severe Pruning History

Owner: crew over-pruned 2 yrs ago (few leaves left). Tree recovered fully. Expert: Pruning didn't cause slime flux (cause unknown). Hire only ISA-certified arborists (isa-arbor.com).