Contact Us

Email us
Phone: +1.678.367.0981
Fax: +1.240.547.1795

Mailing Address

International Society of Arboriculture
PO Box 191
Annapolis Junction, MD 20701
United States

Physical Address

International Society of Arboriculture
270 Peachtree St NW, Suite 1900
Atlanta, GA 30303
United States

Order Delays Due to Physical Inventory

Due to ISA's annual physical inventory, orders placed between
2 p.m. EDT, Thursday, 20 June 2019, and 11:59 p.m. EDT, Friday 28 June 2019, will not ship until the week of 1 July 2019

Please plan your ordering accordingly.

We will resume regular turnaround times
1 July 2019.

Thank your for your patience.

Questions? Please call the customer service team at (678) 367-0981.

    Climbers' CornerTree Academy

    Retrenching Hollow Trees: An International Practice


    As trees age, outer branches are shed as inner crowns emerge. We will examine this phenomenon in many trees around the world.  Sustained routing after pruning overextended branches  results in retrenched and rejuvenated landscape trees. Even clients with low risk tolerance are willing to retain hollow trees when reasonable specifications are communicated and carried out. Hollowness occurs naturally, as taproots and heartwood are shed. Buttresses and adaptive growth provide needed support. The TRAQ form will be used with several species to document response growth, specify mitigation options, assessing and managing residual risk. Vital parts include the flare, the forks, and the vascular pathways in the living tree. Dr. Kevin Smith’s review of the US version.   

    Conference Proceedings Documents


    Guy Meilleur is an ISA Board-Certified Master Arborist, and a Municipal, Tree Climbing, and Utility Specialist.  He is a former staff arborist at University of North Carolina, Instructor at Duke University, and sometimes writes as Detective Dendro.

    Historic Tree Care provides diagnosis, soil improvement, pruning, support and lightning systems, report writing and community education services.


    Climbers' CornerTree Academy

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