AUBURN, Ala. -- In the aftermath of the poisoning of the Toomer’s Corner oaks, Stephen Enloe, an assistant Auburn professor of Agronomy and Soils, tried to stay composed while giving his grim prognosis of the 130-year-old trees.
“It’s just an incredible travesty to see this kind of malicious act occur and it breaks my heart to see somebody so willfully destroy such an incredible cultural landmark for the city of Auburn, for Auburn University,” he said.
School horticultural experts gave the school’s famed trees little chance for survival Thursday, the same day police arrested 62-year-old Harvey Almorn Updyke Jr. for allegedly using the herbicide Spike 80DF to poison the soil.
The herbicide is used in areas where tree control is needed, such as industrial areas, near electrical or pumping stations and, most commonly, along fence lines. It works by inhibiting photosynthesis, essentially starving the tree.
Enloe said Spike 80DF is not a restricted use product, but it is not widely available. Someone would have to go to an agricultural cooperative or pesticide distributor to purchase it. Use of the herbicide in a manner other than how the label directs is a direct violation of federal law, Enloe said.
The soil surrounding the Toomer’s trees had traces of Spike 80DF between .78 parts per million and about 51 parts per million, Enloe said.
Evidence exists that the herbicide can be toxic to some species of oaks at 100 parts per billion.
“Every expert I’ve talked to around the country in mentioning rates up to 51 parts per million, they were very discouraged and did not offer up a lot of hope (for survival) due to the extremely high concentration,” Enloe said.
Gary Keever, the school’s Professor of Horticulture, said Spike 80DF has never been used routinely by Auburn workers and that the presence of the chemical could not be an accident.
Enloe said the trees will take up the herbicide in the soil as the temperature gets warmer.
The leaves will turn yellow and brown and fall off, but it doesn’t mean the tree is dead. He said many species of trees “leaf out” after the initial uptake of Spike, but since the herbicide is in the soil, it will uptake again and repeat the death cycle. This can happen several times before the tree actually dies.
Spike 80DF presents little risk to humans. Enloe said someone would have to consume several pounds of dirt around the Toomer’s trees to see a negative effect, and Tom McCauley of the Department of Risk Management and Safety said it is extremely unlikely to reach the drinking water well, which is 150-200 feet below ground.
But it is lethal to vegetation, especially if it comes in contact with the root zones of other trees. The extent to which the herbicide has spread won’t be known until soil samples are received in 7-10 days.
Keever said the substance is likely to be in the soil for 3-5 years and can inhibit growth for up to 7 years.
The school is looking for solutions. It has already treated the tree beds with a liquid charcoal, which is an absorbent that binds to the herbicide and inactivates it.
Keever said he has gotten many suggestions from across the country for how to remedy the situation, most of which involve replacing the soil (one includes adding a liquid to the root zone and using an excavator vacuum to remove soil from the root zone). He said that will be difficult to do, however, because of the dense roots and granite curbing around the trees.
Keever said if the trees die, the soil could be excavated and replaced, creating an environment for future trees to grow.
For the time being, the trees have been cordoned off by police barricades to prevent further trampling near the base. Although a “Tree Hugging” event has been scheduled by students for Saturday, it won’t be literal.
“The less impact below the trees right now would be the best thing for them,” Enloe said.