The Treaty Oak was once poisoned and a whole nation almost lost hope

In the spring of 1989 John Giedraitis, arborist for the city of Austin, noticed some dead grass under the 500-year-old Treaty Oak. At first, John thought that a city employee just sprayed a mild chemical on the spot. Only after a period of heavy rain swept through the area was the extent of the damage known. The Treaty Oak’s leaves were yellowing and dropping at an alarming rate. The tree had been poisoned.

The Treaty Oak is the only surviving member of the Council Oaks. According to popular local folklore, this is the location in the 1830s where early Texas pioneer Stephen F. Austin met local Native Americans in the grove to negotiate and sign Texas’ first boundary treaty. The tree is a beloved landmark for the city of Austin. Before the poisoning, the crown spread nearly 130 feet wide.

Lab test showed that the Treaty Oak had been poisoned by a powerful hardwood herbicide called Velpar. The test also indicated that the amount used was enough to kill 100 trees. Almost every expert agreed that the Treaty Oak was doomed. The news reached the nation and people came from far and wide to pay their respects to the dying tree.

Texas industrialist Ross Perot wrote a blank check to fund efforts to save the tree. DuPont, the herbicide manufacturer, established a $10,000 reward to capture the poisoner. 

Police ultimately arrested Paul Stedman Cullen after reportedly bragging about poisoning the tree. Prosecutors said he used the herbicide in an occult ritual to kill his love for his counselor at a methadone clinic, protect her from another man and pay back the state for outdoor work he was forced to do while he was in prison.

Cullen was convicted in 1990 for criminal mischief. He was sentenced to 9 years in prison and a $1000 fine.

Intensive efforts were made to save the Treaty Oak. They included applications of sugar to the root zone, replacement of soil around its roots and the installation of a system to mist the tree with spring water. Despite overwhelming odds, the oak did survive. Two-thirds of the tree did die and more than half of its crown had to be pruned.

In 1997, the Treaty Oak produced its first crop of acorns since the poisoning. Today the tree is thriving although it is only one-third of its original size.