Meet the Tree Amigos at Sims Tree Health Specialists, Inc.
- Posted by A. Jordan
- Apr 22
- 12 min read
The Trees Are Calling
We each have a calling in our hearts and minds that drives us to better this world. Some care for the sick, and some care for the needy.
Some are called to care for the trees.
A Reflection of Who We Are
Each member of the Arbor Team at Sims Tree Health Specialists, Inc. understands the valuable lesson in life-long learning. Education enriches their lives with new opportunities to grow their careers, and supports them in the field as they face new challenges.
Since its founding in 1972 by Susan Sims and her late husband, Gary Sims, Sims Tree Health Specialists, Inc. (Sims THS) has been committed to preserving the health and beauty of trees in our communities while also promoting education.
Susan Sims, Board Certified Master Arborist and Owner/Co-Founder of Sims THS recalls some of her best advice for young and old arborists.
“The guy who thinks he knows everything is dangerous because the more you get to know, the more you know you don’t know.”
Most of our ISA Certified Arborists began their careers by tending to the 6-acre privately owned botanical garden and nature-based education site at the Sims Tree Learning Center (TLC). Sponsored by Sims THS, TLC serves as a space for workshops, community gatherings, and educational events that support tree health, environmental awareness, and community engagement.
We look for passion in our team members, and we train them in the hard-skills necessary to become an ISA Certified Arborist.
Meet Susan Sims, “Mrs. Bonsai”
ISA Board Certified Master Arborist, ISA Tree Risk Assessor, California Licensed Agricultural Advisor, California Licensed Agricultural Applicator, Urban Forester, Wildlife Aware Teacher, and Overall Cool Woman.
Susan Sims didn’t set out to become a Board Certified Master Arborist; Arboriculture wasn’t in the cards. She always had the heart of a trainer–first for horses, and then for plants, bugs, and people. She met Gary Sims at a horse show, and their journey blossomed from a shared love of nature into a company that would change the landscape of tree care in California.
Their journey together was built from the ground up, literally. When asked about memories from the early days that still make her smile, Susan says:
“There’s been so many. One that comes to mind was when I was out at a client’s house, and he was wondering what the vertical lines were on his tree. I told him the tree was growing, and those lines were separations in the bark that allowed the tree to expand. ‘Oh! They’re stretch marks!’ he said. I didn’t know until later he was a plastic surgeon.”
She got her start at Burpee Seeds. When Gary was asked by Choate Tree Service to help during Olive Fruit Suppression season, the couple began to lay the foundation for Sims Tree Health Specialists, Inc. As Gary diagnosed trees, Susan pored over insect samples, studying them at the Department of Agriculture with Dr. Eldon Reeves, who would become her first mentor. “I got the bug - literally and figuratively,” she laughs.
When Gary brought home bugs, she brought home answers. She studied entomology books, took classes at Cal Poly one quarter at a time, and learned side-by-side with legends like Dr. Eldon Reeves, Ted Stamen, Fred Roth, Doris Lutz, and Alden Kelly. “I know so many people in the business because I went to school with them throughout the years.” Susan goes on to say:
“We couldn't be where we are today without all of those mentors who’ve helped us along the way. If you walk around the botanic garden here at Sims TLC, there are signs saying which person or organization donated which plant. People want to be helpful because we want to do good things for people.”
Reflecting on what set Sims THS apart, Susan says we’ve always honed in on people’s strengths.
“If one of our Arborists is interested in a specific topic, we encourage them! We value education because it makes you grow. We’re not all about being the biggest company. We’re about growing. Your sales come in when you make people feel that you’re offering them a good enough reason to pay someone to assess with their specialized knowledge. We want to make work fulfilling to our employees and our clients.”
After over 50 years of experience and education, Susan advises the public, “Learn to be sensitive to the plant.” She pauses, and with the true nature of a lifelong educator, she adds:
“Trees are all connected because of mycorrhizae. When you go into a forest, you’re not looking at individual trees. You’re looking at a community connected together and tuned into each other. In a forest, there are the wisest trees.”
Meet Kevin Sims, “The Colonel”, aka, “The Oak Tree Expert.”
Senior ISA Certified Arborist, ISA Tree Risk Assessor, Qualified Applicator, Wildlife Aware Graduate, ASCA Academy Graduate
Kevin Sims didn’t need to be introduced to arboriculture, he was born into it. As the son of Gary and Susan Sims, he grew up learning plant names before most kids had mastered the alphabet.
“I honestly can’t remember [my first unofficial diagnosis]. I do remember riding in the truck with my mom at a young age, visiting clients’ homes and pointing out what trees I knew.”
Now, as an ISA Certified Arborist, Kevin is passionate about educating others on the importance of choosing regionally appropriate plants, especially in California’s wildly diverse microclimates. He’s a fierce advocate for improving public understanding of tree care, and he sees the change on the horizon.
“The general public’s knowledge is getting much better in regards to tree care. While we still see lots of mistakes, some of the more egregious ones are starting to happen less often. While we still see things like topping, it’s definitely at a reduced rate than 20 years ago.”
He’s a man of few words unless you get him talking about trees and bugs.
The Next Generation
Sims Tree Health Specialists was founded on
curiosity, compassion, and a love of all things leafy. But it was never meant to stop with one generation. As Gary and Sue built their careers diagnosing pests and educating clients, their son Kevin grew up tagging along, absorbing knowledge one field visit and bug jar at a time.
Today, he carries their mission forward with his style. And he’s not doing it alone; armed with the education from his mother and late father, Kevin now leads a new crew of passionate arborists who are just as quirky, brilliant and tree-obsessed as the founders themselves.
We Came, We Saw, We Tree-ted
Lord of the Rings introduced us to the Ents of Middle-Earth, the ancient tree shepherds. Wise, powerful, and very slow to act. Our team? Still wise, still devoted to the trees, but a whole lot faster.
Our ISA Certified Arborists and Qualified Applicators are on a mission to protect the health and beauty of Southern California’s urban forests. Armed with knowledge, passion, and the tools of the trade, these heroes respond swiftly when a tree calls for help.
Now, let’s meet the Tree Amigos of Sims Tree Health Specialists, Inc!
Meet Ken McCormick, “Not from Southpark”
ISA Certified Arborist, ISA Tree Risk Assessor, Qualified Applicator, Wildlife Aware Graduate, PINA Permaculture Design Graduate
Ken’s roots are in South Carolina farmland, but his passion developed further at Sims Tree Learning Center. He approaches arboriculture like a scientist with a punk-rock soul. “Everything about plants is biology. Just as our bodies need good bacteria and balanced microbiomes, so does the soil. Carbon is fiber for the Earth.”
He’s particularly passionate about the future of tree care: “There’s an investment into biological pest and disease treatment … bioinsecticides and strains of beneficials that can help repel or improve the health of plants, reducing the number of pesticides used in our industry.”
How is arboriculture punk rock?
“Everything is chaos, whether it be organized or not. Everything is a fight for survival. Arboriculture is as white collar as blue collar gets.”
Meet Ann Hope, “The Legendary”
ISA Certified Arborist, ISA Tree Risk Assessor
Ann’s journey into arboriculture started with banking and merged into pest control regulatory compliance when she needed a job. “Money runs the same direction everywhere, or at least it should! I learned all of this before I got my QAL. I had to get my QAL because I couldn’t sell without it.”
Ann Hope, along with Susan Sims, helped pave the way for women in arboriculture. With her brain for biology and signature character, Ann stormed into a male-dominated industry, solidifying her place as one of SoCal’s premier tree experts.
She reminds young arborists that everything is connected. “There are so many similarities between trees and people,” she says. “It’s the coolest science in the world.” She advises being loud, asking questions, and not taking silence as a rejection. “Don’t be afraid to get turned down when people don’t want to answer.”
Ann, not one to mince words, warns the public, “Quit planting and watering at the trunk of the tree! This promotes root rot at the base.”
Living up to her last name, she offers Hope: “Trees are not accessories, they’re necessities. Give trees room to grow.”
Meet Brandon Watts, “The Carpenter”
ISA Certified Arborist, ISA Tree Risk Assessor, Qualified Applicator, Wildlife Aware Graduate
Brandon Watts doesn’t just diagnose and treat trees, he knows them from the inside out. A senior Arborist at Sims THS with a degree in Biology, his journey started in 2005 when his lifelong friend, Kevin Sims, got him a gig grooming horses. He’s been with Sims ever since, evolving from a field tech into a trusted ISA Certified Arborist, all before the age of 30.
When Brandon’s not out diagnosing trees, he’s crafting custom pieces from reclaimed or storm-fallen wood. He honors the beauty of a tree’s life by giving it a second life through craft.
“It’s great to see how these species look before they become lumber. Some of the coolest types of wood is a tree that’s been affected by a disease or a pest because different grains or patterns or colors come out.”
His favorite? The Ambrosia Wood is where beautiful streaks come from a beetle that inoculates it with fungus. “It changes the grain pattern of the wood. It’s pretty.”
Meet Robin Dawson, “Wild Honey”
ISA Certified Arborist, ISA Tree Risk Assessor, Qualified Applicator, Wildlife Aware Graduate
Robin’s story begins with a keyboard. She started in the office, where everything from service orders to inspection reports were still entered by hand.
“I became interested in what the technicians were doing! I then did a ride-along as a Puller with one of our Arborists and decided that this was what I wanted to do. I’m excited to learn the new ways to protect trees from pests and diseases and how changing the timing of treatments can help best catch pests and diseases. Systemics are especially changing the way we time treatments.”
She’s proud to call herself both an Arborist and a Nana to her grandchildren. She brings grace, calm, and intuition to the trees she treats. Her approach is precise; informed by her early office days when attention to detail mattered.
She chuckled when asked what’s harder, being an Arborist or a Nana. "Being an Arborist is harder physically, but being a Nana is emotionally harder. I love being able to do both!”
Unapologetically feminine and fiercely skilled, she’s one of the rare professionals who makes room for both.
Meet Levi McNally, “Mr. Consultation”
ISA Certified Arborist, Qualified Applicator, Wildlife Aware Graduate
When asked how he got started in arboriculture, Levi said with a grin, “Ken is my friend.” He realized that trees are cool, and he’s good at understanding them, too.
Levi is a thoughtful and clear communicator, translating “Arbor-ese” into plain speech. He’s passionate about sustainability and responsible pruning, telling homeowners to “please keep pruning to a max of 20% of the canopy.”
Levi suggests that the future of arboriculture is bright. “New regulations on insecticides help prevent the killing of bees.” Adding that, the idea of sustainable pest management, with a renewed focus on native trees and plants, is good overall.
He wants kids graduating high school to know that “jobs that don’t require a college degree are out there, if you’re willing to look!” He appreciates Sims THS for allowing him to have a living wage while going to college and pushing him to grow and learn more. Levi recently graduated as a Registered Nurse.
“I like helping people in any way possible, whether helping their mental health by providing them with healthy trees or helping their physical health. In general, I want to improve peoples’ overall life quality.”
Meet Logan Foltz, “Mr. Rancho Palos Verdes”
ISA Certified Arborist, ISA Tree Risk Assessor, Qualified Applicator, Wildlife Aware Graduate
Logan started his path to arboriculture on an avocado orchard and passionfruit farm, where he became interested in how things grow and sustainable resource management. His love of plants brought him to the Brooklyn Botanical Garden, and, from there, to California.
He’s all movement and joy, scrambling into trees like he’s a part of them and hopping in and out of his truck with energetic agility. He’s excited about where the field is going, emphasizing that as “technology improves, sustainable and environmentally responsible practices are easier to conduct.”
He’s serious about care and conservation, too. “Trees must not be watered like annuals,” he warns. “They’re perennials with deeper roots. Any tree chosen for SoCal should be chosen for its drought tolerance.”
Why are you known as Mr. Rancho Palos Verdes?
“We got a lot of clients out there dealing with the Dotted Paropsine Leaf Beetle on their Eucalyptus. After going out for so many tree health and wellness assessments, the neighborhood knows me pretty well.”
Meet Hayden Fringer, “James Dean”
Arborist in Training, Qualified Applicator, Wildlife Aware Graduate
Hayden grew up across from an orchard in an agricultural family. He’s always felt most at home in the outdoors. With dirt under his nails and desert sun in his eyes, he sees things through a farmer’s lens: if the treatment works, it’s worth using. No thrills. Straight facts.
“You’re not going to see progress right away. Trees are slow-growing organisms. Issues with them take time. There’s not an instant-gratification, snap-of-a-finger resolution. Unless you’re cutting them down.”
Grounded and curious, Hayden’s loyalty lies with what the science says. “This career pushes you to constantly keep learning. No one day is the same. It’s a working-class job, and you’re outside doing stuff. Nature is Punk!”
Meet Humberto Castellon, “Rare Fruit Guy”
Arborist in Training, Qualified Applicator, California Rare Fruit Grower Member
Before Humberto revived sick trees, he was known in the garden as “The Rare Fruit Guy.” He first appeared in our “Meet the Gardenshians” blog post, where his passion for plants and fruit-bearing trees blossomed into a career in arboriculture.
Proving what we said earlier about training passionate people, Humberto’s now training to be an ISA Certified Arborist. When asked what he’s looking forward to for the future of arboriculture, he lit up. “I’m excited about the new progress in organic treatments. I am the Organics Man!”
From the garden grounds to the Urban Forests, his dedicated love for learning drives him. He wants to see the planet healthy through a no-nonsense approach to tree healthcare. “I want to get diseased trees back into good health!” He’s looking forward to becoming ISA Certified.
Summary
Justice for your trees? It’s what the Tree Amigos do best.
They provide and follow through with a specialized treatment plan designed to help your trees dance in the wind the way they deserve.
The Tree Amigos are ready to tackle your tree trouble head on. Their fresh outlook on tree health and commitment to quality care set them apart.
No need to worry about them breaking into song and dance. Go online at https://www.simsths.com/ or by calling the office at 951-685-6662.
About Sims Tree Health Specialists, Inc.
Sims Tree Health Specialists, Inc. is dedicated to the preservation, education, improved health, and safety of trees. Sims THS has provided California’s Urban Forests with premium healthcare since 1972. To learn more, visit our website: https://www.simsths.com/
Sims THS offers services with our ISA Certified Arborists in the following:
Diagnosis and Disease Management, Pest Suppression, Organic Solutions, Fruit Suppression, Drought Protection, and Arborist Assessment Reports and Preservation Plans.
In addition to providing quality tree health services, the Sims family is known for their educational pursuits. In 1996, they started the Sims Tree Learning Center (TLC), a 6-acre botanical garden and research facility sponsored by Sims Tree Health Specialists, Inc. The facility houses multiple types of gardens including a cactus and succulent garden and one of the largest collections of Palms in the Inland Empire. Learn with us!
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