The Conejo Valley, includes Thousand Oaks Westlake Village and Newbury Park  Agoura Hills and Oaks Park

Arborist continues to expand urban forest he and father created

The Midwest had Johnny Appleseed.

Thousand Oaks has Davy Oak Tree or Morty Acorn.

Dave Mortimer, certified arborist and Thousand Oaks resident, is still working on his pseudonym.

"I think about that all the time," Mortimer said, laughing. "I'm throwing acorns all over the place."

Appleseed, the prolific planter of yore, covered swaths of America's Midwest with apple trees. Mortimer has covered 15 acres with 1,000 oaks in a decade.

He gets a kick out of being able to answer yes when asked if there are 1,000 oaks in Thousand Oaks. And they are all in one place, viewable by thousands traveling north on Highway 23.

"I love trees," said Mortimer, who owns a tree service. "This was a dream of mine, just to create a forest."

Mortimer's forest was started with 100 trees on city-owned land in 1998 as part of Thousand Oaks' Arbor Day celebration. The land, called La Jolla Open Space, is at the end of a quiet cul-de-sac in a residential neighborhood, past a chain-link fence and down a dirt road.

Following the road down a hill, a visitor comes upon young, spindly oaks, irrigated with water from white PVC piping. Where the hill slopes into a valley, the trees are older, bigger and denser.

Most of trees are indigenous

Most of the trees are indigenous to the area coastal oaks with dark green crinkled leaves with tiny pointy ends, and valley oaks, whose multilobed leaves are lighter. But there are a few other types of oaks, too, and a handful of native pepper trees.

"A lot of credit goes to the city, too, for having the foresight to say, 'Let's let this guy go out and build a forest,'" Mortimer said. "The city of Thousand Oaks believes in this kind of thing."

'One-of-a-kind guy'

A living labor of love, maintenance and planting are done for free by Mortimer and his crew. Mortimer also gladly takes volunteers to help with the forest. It ensures future generations know what it's like to walk in a dense grove of plentiful oaks, he said.

Jana Covell, an associate analyst for the city, praised Mortimer and his work.

"He's just a one-of-a-kind guy, I think," Covell said.

Mortimer takes the top off his Jeep and drives it into the valley to tend to the trees on sunny days. But a recent morning was overcast, so he opted for his mammoth Ford 250 super cab truck, which he inched down narrow dirt paths he had bulldozed for hikers and horse riders.

"Isn't this kind of cool?" Mortimer asked, as oak branches scraped the truck's side view mirrors. "You've got trees on both sides where there used to be nothing."

When the 58-year-old grandfather talks about trees, there is liberal use of the word "cool," and his words move fast with an inspirational enthusiasm reminiscent of a sports coach.

He looks more like a football coach than a tree-loving arborist. Built like a bulldog, Mortimer is compact and sturdy with short-cropped silver hair. A pair of wraparound sunglasses was perched on top of his head, and he wore baggy shorts, sneakers and windbreaker emblazoned with the International Organization of Aboriculture patch.

Mortimer pointed to one of the younger valley oaks.

"That tree right there, my father planted from an acorn in one of the last moments of his life," Mortimer said.

Father died of lung cancer

Daryl Mortimer died in 1999 of lung cancer. During his illness, the elder Mortimer helped his son nurture the fledgling forest by planting acorns in pots. When they became seedlings Mortimer planted them in La Jolla Open Space, nudging along a tree population that can be hindered by acorn-loving squirrels, rabbits and gophers.

Mortimer estimated he and his father started at least 300 of the trees from acorns. "It's like my dad's grove," Mortimer said of the cluster of trees. "Isn't that cool? When he wasn't able to do things toward the last months of his life, he would come over to my house and he'd plant trees in pots and say, 'Here's something to remember me by.'"

Throughout the years, Mortimer has received calls from people asking if they can plant a tree in memory of a loved one. Mortimer has always said yes. Only he and the person's family know which tree it is.

Family moved from Iowa

Daryl Mortimer always had a knack for growing things. The family moved to Thousand Oaks from Iowa in 1971. Whenever the family had a backyard, Daryl Mortimer would transform it into a garden, thick with vegetables.

It was dead wood that led Dave Mortimer to a career nurturing living trees.

Driving past a Santa Rosa Valley farm, Mortimer noticed dead trees on the property. He asked the farmer if he could cut them down to sell as firewood. Mortimer was delivering the firewood when a man asked if he could cut down a tree. Mortimer agreed; one thing led to another and soon he was "doing trees."

"After a while I started realizing, you can't just go out and whack a tree," he said. "You have to understand what makes a tree grow."

He never went to college, but Mortimer has had years of aboriculture education, earning his certification through the International Organization of Aboriculture. Mortimer is recertified every three years.

"I can quite often figure out what makes a tree tick," Mortimer said. "What a tree needs. Does it need fertilizer? Does it need water? Does it need to be left alone? I've always been able to help trees out, and it's a fun thing to do."

The grove's ground is littered with pieces of bark and wood. The woody carpet is thick and spongy. This is nature's often overlooked Miracle-Gro: mulch.

Mortimer bent down and scraped away some wood chips before digging his bare hand into the ground. He pulled out a hunk of damp, rich earth.

Dirt is just dirt," he said, jutting his chin toward a light brown, dusty trail. "Soil is something you can grow in."

Mulch makes growth medium

Mulch makes the soil. The wood chips, hauled in from Mortimer's tree jobs, are spread across the ground about a year before he plants a section of trees. With water and time, the plant material decays, creating nutrients that leach into the soil and are taken in by trees.

It's all about creating the right medium for the trees to grow in.

Mortimer waters the trees for three years; after that, the oaks become self-sufficient because the mulch creates an environment found in a normal forest.

Before a forest grew along Highway 23, these 15 acres were nothing more than open ground. There were about 15 mature oak trees, some more than 200 years old and dying of old age.

The trees Mortimer has planted in the past decade have grown so thick and full that their canopies have blocked out the sight of the highway, making the roar of traffic sound like rushing water. But the dense green canopy of the forest can be seen by drivers on the highway. It's a satisfying legacy.

"It is a sense of pride because it's something that will be here forever," Mortimer said. "Well, it will be self-sustaining even when I'm done, because it all comes down to mulch."