Returning from the grocery store on a recent evening, Richard Seaman was shocked to see about a half-dozen redwood trees near his home stripped of their branches.

The 55-year-old resident of Camp Meeker, a community of mountain shanties and rustic villas tucked in thick woods south of the Russian River, had expected Pacific Gas and Electric Co. to do tree work in the area. He even welcomed the pruning as a way to keep overgrown vegetation from toppling power lines and possibly starting another destructive fire.

But, like a growing number of Northern California homeowners, he wasn’t prepared for just how far the embattled utility company would go to cut back the forest.

“It’s mind-blowing,” Seaman said, craning his neck to look up at giant redwoods with no limbs for 60 feet up one side of their trunks, the result of a process he has taken to calling “radical” delimbing.

“This damage will take a couple of generations to repair,” he said. “In fact, it might not be possible to ever repair the damage.”

In places such as coastal Sonoma County, the Santa Cruz Mountains and the Sierra foothill towns of Butte County, many residents who fear the state’s worsening infernos are also frustrated with how many redwoods, old firs and landmark oaks are coming under the ax in the name of fire safety.

While PG&E is under pressure to chop trees to protect a power grid that has sparked some of California’s most catastrophic wildfires, critics say the work is not only environmentally harmful but counterproductive.

The trimmed trees may reduce the fire risk this year or next, they say, but the widespread slicing and dicing could take a long-term toll on the health of the forest. And an unhealthy forest is ultimately more likely to burn. Clearing bigger trees such as redwoods, critics add, also could bring more sunlight into the wildlands, boosting the growth of flammable grasses, brush and saplings.

It doesn’t help that the work is being done in a hurry and by contracted tree companies that sometimes have little understanding of California’s forests. A report last week by a court-appointed monitor who has been evaluating PG&E’s safety practices found that crews were failing to identify hazardous trees, track progress and train personnel.

“The clearing is so random, so inconsistent,” said Kellie Anderson, a resident of Angwin in rural Napa County, who worked with her neighbors to stop PG&E contractors from cutting “centennial” oaks, among other trees, but with little success. “What you get depends on the mind-set of these crews.”

Anderson said she has counted contractors from 24 states, based on license plates, including Maine, Florida and North Dakota, and few have been receptive to her requests.

“Each day a new mean, ratty, hostile crew appears in Angwin, hell-bent on taking more trees and making more money,” Anderson wrote in an email.

PG&E officials acknowledge that not everyone is happy with the tree clearing. But after the company’s power lines were blamed for starting 17 of the blazes in the Northern California firestorm in October 2017, as well as last year’s unprecedented Camp Fire in Butte County, officials say they need to ensure that trees don’t interfere with electrical infrastructure.

“We understand our customers’ love of trees, and we appreciate the value of trees,” said PG&E spokeswoman Brandi Merlo. But, she said, “Given the wildfire conditions we’ve seen in recent years, this is important work.”

The company also has begun to proactively shut off electricity during periods of warm, windy weather, a move proponents say is crucial given the escalating fire danger but has similarly come under attack.

The increase in tree trimming kicked off last year as part of an enhanced vegetation management program that calls for more clearing around power equipment in areas of high fire risk.

In addition to meeting a longtime 4-foot clearance target — which generally means cutting vegetation 12 feet around wires so it doesn’t quickly grow back — crews are pruning all overhead branches and removing any tree at risk of falling. Such work is being done along 25,200 miles of distribution lines between Bakersfield and the Oregon border.

About 40 prime contractors have been hired for the task, according to PG&E, with more than 3,500 people on the job. The employees include trained arborists and foresters, the company said. By the end of the year, the utility expects to prune or remove roughly 305,000 trees along power lines, almost twice as many as last year.

Bill Stewart, a forestry specialist at UC Berkeley, said the aggressive tactics are generally a smart way to reduce fire danger, even if they ruffle some communities.

“PG&E was probably too lax over the past few decades when homeowners wanted less clearance,” he said. “The contractors (now) are often having to make up for decades of branch infringement.”

Stewart acknowledged that tree clearing can increase vegetation growth and add combustible fuel to a forest’s floor, but he said a tree toppling an electrical line poses a greater fire risk.

Critics of PG&E say the utility should harden its electrical equipment so that even if a branch, animal or balloon strikes a line, it shouldn’t spark. Covering wires with insulation material and running wires underground lower fire danger, but neither strategy is widely embraced by the company. Bare, overhead wires have been the industry norm.

“Trees are their whipping boy,” said Robin McCollum, a Chico resident who formerly worked as Butte County’s tree foreman and is concerned about excessive clearing in his area. “They’re not fixing the wires, so they cut the trees.”

In Santa Cruz County, where PG&E has met resistance for its trimming, Boulder Creek resident Nancy Macy was stunned to see a cluster of Douglas firs removed from her neighbor’s property. She believes the power line could have simply been swapped out with a safer one.

“They cut down 25 trees to protect a single strand of wire,” Macy said.

PG&E officials say the cost and time involved in putting up insulated power lines or undergrounding wires is often prohibitive, though they’ve committed to the upgrades in a few high-risk areas.

The town of Paradise, which was largely destroyed in the Camp Fire, is being rebuilt with underground lines. Putting in such lines typically costs $2 million to $3 million a mile, experts say, at least three times as much as running wires overhead. The work can take years to complete.

PG&E also plans to insulate 150 miles of power lines this year. The cost of such “covered conductors” is much less than undergrounding wires but more than installing bare lines. Within the decade, the utility hopes to have 7,100 miles of covered wire in place.

Critics say insulation work and undergrounding should be happening much more quickly.

“It’ll be 30 or 50 years before the wires are replaced,” Macy said. “In that time, with global warming and all the windstorms and heat, we’re looking at our area suffering catastrophic fires like we’ve seen elsewhere.”

In Camp Meeker, criticism of PG&E’s focus on tree cutting goes beyond Seaman’s home. Some of his neighbors have posted handwritten signs on fences or in lawns instructing PG&E crews to stay away from their trees.

Regardless of a homeowner’s wishes, though, the utility has the right to remove hazardous vegetation around its equipment. Conflicts have emerged between PG&E crews and residents over trees that may be dozens of feet from power lines but are considered by the company to be risky.

Some people in Camp Meeker and elsewhere report being “threatened” with lawsuits if they protest the tree cutting. PG&E officials say they only seek to inform landowners of their legal liability should a wildfire start on their property.

Seaman, who heads up the local Fire Safe Camp Meeker but speaks for himself, keeps a list of what he sees as PG&E’s problematic tree work.

He pointed to more redwoods that have been pruned and now allow sunlight to nourish dry brush in the forest. He noted several bay trees that have been cut and left alongside the road, which he sees as potential fuel for a fire, and downed branches from pruned redwoods and firs that could present a similar hazard.

Seaman plans to use his wood chipper to clean up after the crews.

“I’m not saying I want PG&E to stop what they’re doing,” Seaman said, stressing he’s appreciative of much of the company’s thinning efforts. “But this climate of fear is making things happen far too rapidly. I want them to pause until experts can do an investigation: Is limbing redwoods really going to help fire safety? Or is it going to hinder it?”

Kurtis Alexander is a San Francisco Chronicle staff writer. Email: kalexander@sfchronicle.com Twitter: @kurtisalexander