Fairbanks Experiment Farm, Georgeson staff begin weeding out chokecherries

On Monday, another step was taken in the long process of weeding out popular but invasive chokecherry trees on the University of Alaska Fairbanks Troth Yeddha’ Campus. 

Seven chokecherry trees (Prunus padus and Prunus virginiana) were removed from Georgeson Botanical Garden and the Fairbanks Experiment Farm, including a tree planted in 1993 in honor of Arbor Day. Georgeson Directing Manager Lacey Higham said two of the trees were already dead and the others were in rough shape.

The trees will be replaced with “Thundercloud” cherry plum (Prunus cerasifera), a flowering plum with dark purple leaves and “Meteor” cherry, a dwarf tart cherry tree, Higham said. 

“Both trees have exquisite blossoms, are hardy and produce edible fruit,” Higham said. 

They are noninvasive and were sourced from a local greenhouse. 

It's a process that will be followed across campus: Chokecherries won't be targeted for removal, but when they die, they will be replaced with noninvasive species.

Staff members from the UAF Cooperative Extension Service, the farm and the garden cut the trees close to the ground and then painted herbicide on the fresh-cut stumps to kill the root systems and keep the trees from resprouting in the spring. 

“Fall is an ideal time to remove chokecherries because it can take several months for the herbicide to completely kill the root system,” said Gooseberry Peter, an integrated pest management research technician with Extension. The root system must be neutralized prior to removing the stump or digging holes for planting new trees, or a new generation of chokecherry “suckers” will emerge where there was only one tree before, he added.

“If you don’t apply herbicide immediately after cutting the tree down, you’ve created an even bigger problem than what you started with,” Peter said. 

Chokecherries have been widely planted for decades in Alaska and are attractive plants with showy, sweet-smelling flowers in the spring and edible berries, Higham said. That sentiment has changed in the last decade, as the trees spread aggressively into a variety of habitats, replacing native plants and impacting natural food webs.

Peter said the trees’ spread is likely due to changing conditions and the sheer number of the trees. 

“When people were planting them originally, they weren’t expected to go feral,” he said. “Now they’re known to be extremely feral. There are more plants, and as there are more of them where they shouldn’t be, we’re more aware of the impact.”

These aren’t the first chokecherry trees that have been removed on campus. In fall 2023, Extension worked with UAF facilities and the Fairbanks Soil and Water Conservation Service to remove chokecherry trees around its state office at 1751 Tanana Loop. Those trees have been replaced with saskatoons, also called serviceberries (Amelanchier alnifolia).

049-25