Many of the landmark trees that line Russell Boulevard to the west of Davis are being cut, due to a fungus known as thousand cankers disease that is killing black walnut trees across many western states.
“It is sad to see this happen, but it’s really inevitable,” said Eldridge Moores, an emeritus professor in the UC Davis geology department who has lived in a house facing Russell Boulevard since 1975. Moores has long appreciated the mature walnut trees: not only are they beautiful, they also provided shade for the bike path that leads to town. “And I’ve always looked on them as an insurance policy against errant drivers,” Moores added.
But Moores said that as some of the old walnut trees have become diseased and frail in the last few years, “they’ve started dropping limbs, sometimes 10 inches in diameter. We had one come down just a couple of weeks ago.”
Moores said that some of the remaining uncut trees along Russell may look like walnuts to casual observers, but they are actually ailanthus trees (sometimes known as “Tree of Heaven”) — a species from China planted in this region longs ago, now often regarded as an invasive pest.
Keith McAleer is executive director of Tree Davis, a nonprofit that has planted many trees on Russell (and elsewhere in town) since 1992. McAlleer said that county government informed Tree Davis of plans to cut the old walnut trees, “and we recommended that an arborist assess the health of the trees. The county did hire an arborist, and most of the walnut trees (now being cut) were (already) dead — though walnuts will send up shoots from their roots indefinitely.”
McAleer said that the walnut trees along Russell within city limits “are much better cared for … there are only a handful of dead ones. Tree Davis would like to save these walnuts if possible. They are iconic, many over 120 years old.” He said that mistletoe has been a problem for years, and Tree Davis is assessing whether it is feasible to treat the surviving walnut trees for thousand cankers disease. Tree Davis is also working with neighbors in the Russell Boulevard/Patwin Road area to plant new trees replacing those now being cut — ideally “a more diverse canopy” less susceptible to a particular pest or disease.
Roger and Ann Romani have lived on Russell Boulevard for more than 50 years, in a historic home built in 1887 for Hugh LaRue, an early resident in this area. LaRue owned much of the land fronting Russell between Highway 113 and Cactus Corner (Highway 98 and Russell Boulevard). Ann Romani, a devotee of local history, said that LaRue and his sons planted many of older walnuts — at that time, the state subsidized planting trees alongside country roads, and photographs of Russell Boulevard were featured in state highway publications. Russell Boulevard became part of the Lincoln Highway — the nation’s first transcontinental highway for automobiles, designated in 1913.
Roger Romani, a professor emeritus in the plant sciences department at UCD, said that the walnuts along the county portion of Russell “have not been taken care of very well,” but added “some of the trees (in city limits) are doing exceptionally well.”