Shasta Drive resident Karen Rosson knows about trees. She worked at the Genoa Tree Farm, so she knew that when the leaves on one side of the 14-year-old pin oaks in her backyard turned yellow, that was a bad sign.
"Oaks require acidic soil so I pumped that up, but the leaves kept turning yellow," she said.
This spring, when the leaves came out they were green until the big rainstorm hit on July 8.
"After the big dump, the leaves turned daffodil yellow," she said.
On the other side of her back fence is the easement maintained by the Gardnerville Ranchos General Improvement District.
The trees are just a few feet from her back fence and Rosson said she sees that several of the trees along the fence line behind homes on Shasta and Purple Sage are either suffering from yellow leaves or have already died.
She contacted the Gardnerville Ranchos District Manager Bob Spellberg to ask about what they spray to keep down the weeds in the right of way.
Spellberg said the district uses a herbicide called Krovar, which is produced by Dupont.
When Rosson did an Internet search on the product she learned that it enters root systems and then turns plant leaves yellow, leaching out the chlorophyll that allows them to manufacture food using photosynthesis.
Rosson said she called Dupont and they agreed that the herbicide could be affecting her trees.
"I told her I lived adjacent to property that had been sprayed with Krovar, and my trees along that property line are in trouble," she said. "Before I could even explain, she offered that the side of the trees facing the sprayed area were turning yellow."
The Dupont representative told Rosson that there was little she could do to save the trees.
"She sadly informed me that flooding the area will do no good and that I will probably lose the trees that already have the yellowing," she said. "If not this year, surely by next year they will be gone."
Rosson said the oaks are 30-feet tall and are irreplaceable.
Spellberg said the district stopped spraying Krovar behind Rosson's Shasta Way address.
He said the area is treated with a pre-emergent between January and March in the winter.
"We stay 1 foot away from the fence line," he said. "It's a pre-emergent, it kills everything in its sight that's not already grown. We spray it in the winter and when the rain comes, it soaks in. We might do some touch-up using Round-up later in the spring."
Spellberg said he's familiar with the neighborhood and there are a couple of dead trees and some others that are turning yellow.
Rosson lives in Unit 5, which was built in the early 1990s. There were some public utility easements that some neighbors asked the district to abandon, which it did. But residents of Purple Sage asked the district to leave the open space behind their homes, saying they would be happy to keep it clear of weeds.
"After a few years when no one cleaned it up, we started treating that open space with spray," he said.
Spellberg said the district uses the same chemical on the shoulders of Ranchos streets that don't have curb and sidewalk.
"What do we do?" he said. "Do we just let it overgrow. I feel really bad."
Rosson said she wanted the district to study the products it uses before applying it to the right of way.
"The Krovar information sheet clearly states, 'Do not apply Krovar IDF in locations where it may be washed or moved into contact with desirable vegetation,'" she said.
Rosson said desirable vegetation surrounds the area.
"Rain or melting snow is all it takes to move it beyond the original spray borders and to the roots of nearby desirable vegetation."
She said that even if the district stops spraying Krovar, it will remain in the soil for the next 6-18 months.
"We won't spray it anymore," Spellberg said. "We have to figure out something else to do."
Rosson asked if the district will take responsibility for removal and replacement of her trees if they die.
"I'm not sure if the district is going to take responsibility," Spellberg said "If she goes before the board and asks for something then that's between her and the board."
