Toomer's Oaks' Update - Montgomery Alabama news.

Toomer's Oaks' Update

Eighteen months have passed since we learned the Toomer's oaks had been poisoned with Spike 80DF (tebuthiuron). The Task Force has worked closely with AU Landscape Services to remediate the deadly effects of the herbicide, while minimizing further injury to the trees in the process. This update includes a summary of measures taken, an assessment of the trees' current condition, an overview of the charge given to the University's Tree Preservation Committee related to tree replacement, and an acknowledgement of those involved in remediation and communication.

2012 Remediation Efforts.

  1. Spring. Landscape Services applied soluble fertilizer to each bed every 2 weeks for a total of 6 applications.
  2. Spring. Landscape Services applied a compost extract, EarthMAX (4 gal in 200 gal water to each bed), every 2 weeks for a total of 5 applications.
  3. Mar. Cortese Tree Specialists, Inc., Knoxville, TN, injected the flare roots of the College tree and the base of the Magnolia tree with 25 and 20 gallons, respectively, of a 1.5% sugar solution (2 glucose: 2 fructose: 1 sucrose).
  4. April. Faculty and a graduate student in Horticulture measured photosynthesis levels in the canopies and rhizomic shoots of the two trees on. Levels were extremely low in the canopies of both trees indicating the herbicide was present and active.
  5. May. Landscape Services pruned both trees to remove many of the larger dead branches to reduce the risk of branches falling.
  6. May. Landscape Services injected 10% sucrose (table sugar) into the trees using a macro-infusion system similar to that used in March. The College St. tree absorbed 23 gallons of solution over 5 hours, while the Magnolia Ave. tree absorbed 25 gallons over 7 hours.
  7. Mar.-Aug. Members of the task force inspected the tree crowns periodically for dead and/or dying branches using a ladder or bucket truck.
  8. June. Landscape Services applied trunk sprays and root drenches of insecticide to the trees to control Ambrosia beetles that had bored into the College St. tree.
  9. Aug. Trees were inspected for dead wood and weak branches. Because most of the smaller branches in the College St. tree were dead and decay was present in larger branches of both trees, both trees were pruned for safety reasons. 

The Trees' Current Condition

Both trees leafed out in spring 2012 with healthy foliage, but since then both have steadily declined.  The College St. tree is about 90% defoliated and bare branches show no signs of developing new leaves. The Magnolia Ave. tree has more foliage but most of the leaves exhibit signs of herbicide poisoning, and if they follow last year's pattern, will abscise before the end of summer. The long-term outlook for the trees is not good. Bare branches will die without refoliation and their removal will leave trees that are aesthetically dead if not actually dead. Replacement would be the next step; however, this process would probably not occur for 6 to 18 months, depending upon the size of the new trees. Rolling of the trees will be allowed this fall; however, trees will continue to be evaluated during this period for branches that may become hazardous; rolling may be temporarily stopped until these branches are removed.

What's to Come. The AU Tree Preservation Committee (TPC) will make a recommendation to the President in the near future whether to continue remediation or begin the process of replacing the trees. The TPC's  current charge is to:

  1. Determine and make a recommendation as to what species of oak should be used to replace the current Toomers' oaks. The replacement tree or trees will most likely be overcup oaks.
  2. Determine the size of the tree that should be transplanted to Toomer's Corner.   If the decision is made to use nursery-grown trees that have been root-pruned during production, replacement trees could be dug before they begin to form new leaves in spring 2013, typically around mid- to late March, and planted after all contaminated soil beneath the plaza and extending into Samford Park  is removed. If the decision is to replace the trees with one or more larger overcup oaks from the landscape, trees will be root-pruned eight to 12 months before they are dug.
  3. Once 1 and 2 are complete, identify or develop a process by which candidate trees to be transplanted can be identified. 
  4. Depending on the candidate trees, develop a plan for preparing the tree(s) for transplanting by root pruning or other appropriate methods.
  5. Monitor the health of the existing Toomers Oaks, and once dead, give some advice on how long the tree will remain structurally sound, so they can remain in place and continue to be rolled. 

 Groups Involved with the Remediation Who have Donated Either Services or Product.  

  1. AU Landscape Services
  2. AU Task Force comprised of scientists from several departments, schools and colleges in the University including the Departments of Horticulture, Agronomy & Soil Sciences, Chemistry & Biochemistry, and Civil Engineering, and the School of Forestry & Wildlife Sciences.
  3. AU Office of Communication & Marketing
  4. AU Risk Management and Safety
  5. Alabama Department of Agriculture
  6. Dow AgroSciences, Indianapolis, IN
  7. NewFields, LLC, Birmingham, AL
  8. American Plant Services, Sylacauga, AL
  9. Cortese Tree Specialists, Inc., Knoxville, TN
  10. Harrell's, LLC, Sylacauga, AL

The task force received countless emails and phone calls offering services, products, and encouragement. We are most appreciative of this support.

Copyright 2012 WSFA. All rights reserved.

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