Story and Photos by Brad Bowman

A Kentucky Division of Forestry (KDF) nursery in the hills of Morgan County — with some key partners — could be essential to stemming a looming blow to the bourbon boom’s future. 

Growing in the nursery are rows and rows of white oak seedlings — a species crucial to the production of bourbon barrels that soon could be in short supply.  

As the current white oak population ages over the next 50 years, there’s not a sustainable source of new seedlings to supply the unprecedented demand from bourbon production and other timber-related industries. The worst case projections could be as much as a 77 percent decrease in regional mature white oak. 

In response, the White Oak Initiative has brought together stakeholders from throughout the region to promote and ensure the sustainability of white oak forests. A key part of this effort is a first-of-its-kind program called the White Oak Genetics and Tree Improvement Program, which is working to improve the white oak genetic makeup in Kentucky and the rest of the white oak range in the eastern U.S. Those with ideal genetic qualities, such as a faster growth rate and a straight profile, could one day become the charred barrels legally required for aging bourbon. 

 “With white oak, there’s a glitch,” said Darren Morris, an extension forester with the Department of Forestry and Natural Resources at the University of Kentucky. “It’s not that we are cutting more than we are growing, it’s that we are not reproducing those young seedlings to replace them in the forest.” 

It takes at least 75 years for a white oak to grow to the right size and quality to become a stave log, said Morris, who also serves as the southern region coordinator for the White Oak Initiative. 

“Tree improvement at this scale for a hardwood species has rarely been attempted before,” said Laura DeWald, a tree improvement specialist at UK’s Department of Forestry and Natural Resources, who is implementing the White Oak Genetics and Tree Improvement Program. “No other state is doing this at the scale we are … This idea of a tree improvement program was created at the University of Kentucky and the Kentucky Division of Forestry was involved in the very beginning.” 

Improving the White Oak 

The White Oak Genetics and Tree Improvement Program is attempting to find and replicate white oaks which have “superior genetics,” or traits desirable to cooperages and lumber producers, said Kentucky Division of Forestry Environmental Control Manager Charlie Saunders. 

Such quality white oaks were once naturally abundant in Kentucky and the rest of the region. But now as they compete for sunlight above the forest canopy — with species like red maples and hickory that create too much shade and stunt the growth of white oak seedlings — state forests are left with low quality trees to repopulate the area.  

The program will eventually create a seed source for KDF, which will plant the seeds at its nurseries and sell the resultant seedlings to the public.  

The idea is to “help turn the curve of poor quality white oak dominating our forest to quality oaks providing Kentucky with superior products,” Saunders said. 

Jeff Stringer, chair of UK’s Department of Forestry and Natural Resources, developed the idea for the project, which was initially funded by KDF, UK’s Department of Forestry and Natural Resources, Kentucky Agriculture Experiment Station and the USDA Forest Service Southern Resource Station.  

Stringer said the program provides a vital piece of the puzzle needed to tackle the white oak problem.  

“We were seriously lacking in our basic knowledge of white oak genetics, and we certainly did not have a robust tree improvement program for white oak,” Stringer said. “Both are needed for us to have the ability to provide solutions to help with the sustainability of our natural populations and certainly to help provide solutions for future threats.  

“Our White Oak Genetics and Tree Improvement Program is building these critical components, with the ultimate goal of improving the sustainability of this cornerstone species that provides significant economic and ecological value to Kentucky and states throughout the region.” 

Since the program began in 2019, KDF foresters, various state agencies, non-profit organizations and volunteers have collected more than 17,000 white oak acorns — and counting — from nine states, representing 91 parent trees, and planted them at the Morgan County nursery. Out of those, 64 parent trees produced enough seedlings to move on to progeny testing, where 1-year-old seedlings will be planted to evaluate parent tree traits of interests to stakeholders, DeWald said.  

The progeny tests will take several years and take place at several sites throughout the region, with the largest “master” progeny test occurring in Kentucky. “We’ll pick the best 30 seedlings from each parent tree,” DeWald said. “We want seedlings that will invest their energies in growing straight up without multiple branches and have a large diameter at the root collar, where the stem turns into the root system.” 

Acorns collected in 2019 are now seedlings growing in the nursery and will go to progeny test sites in March of 2021, she said.  

As the best quality seedlings are identified, they will be sent throughout the eastern U.S. to other state’s nurseries and to any interested landowner who wishes to have a white oak seed orchard on their property. These seedlings can be planted back into their appropriate, native environments and climates for replenishing white oak forest systems and allow nurseries to harvest the acorns to create the next cycle of quality white oak trees. 

Throughout the process, select white oak twigs will be grafted to conserve genetic material of the parent trees for creation of future seed orchards. Earlier this year, more than 50 successful grafts were made for two replicated white oak clone banks. These banks will save and establish the superior white oak genetic material needed to produce future orchards. 

Eventually, DeWald hopes to be able to mix pollen from selected parent trees to breed white oaks with ecological and economical traits such as insect and disease resistance.  

Sustainable Industry, Healthy Forests 

Distillers have taken notice of this work and signed on as partners in the program, offering land for the growth and research of genetically superior trees. Those partners for now remain private.  

Since the turn of the century, bourbon production has increased 360% and is an $8.6 billion signature industry that accounts for more than 20,000 jobs in Kentucky. In January of this year, the Kentucky Distillers’ Association reported 9.3 million bourbon barrels in Kentucky.  

In 1963, bourbon was the top-selling liquor in the U.S., and Congress declared bourbon “America’s Native Spirit,” requiring that it can only be made in the U.S., with a grain mixture of at least 51% corn and must be aged in new, charred oak barrels, among other provisions.  

“It really gets your attention in this industry, about the need for … the young white oak,” Kentucky Distillers’ Association Senior Director of Governmental Affairs Bryan Alvey said during a 2019 presentation. “We hope people are going to start taking more initiative and that it’ll be around for a long time, for the grandkids to make barrels and the grandkids to run the cooperages.” 

Overall, the endgame is sustainability — not just for the sake of bourbon but for healthier forest ecosystems. 

White oak trees provide not just pulpwood, veneer, staves or saw timber, its acorns produce the most digestible food of any oak species and  an important habitat for the numerous wildlife living in its forests. 

“It’s more than white oak can produce barrels,” DeWald said. “A forest is a giant, complex, beautiful entity … We want to make sure the forest remains functional the way nature intended it.” 

The Kentucky Division of Forestry operates two seedling nurseries for the purpose of planting on public and privately-owned land. Read more about those nurseries here. Learn about the Division of Forestry’s other initiatives here.