Our ISA Certified Arborists
Every tree on your property deserves expert care. Our ISA Certified Arborists bring science-backed knowledge, years of field experience, and a genuine passion for trees to every job we do.
Employee spotlight: Andrew Liebetrau
Sales Lead and ISA Certified Arborist (WI-1674A). Get to know the people who'll be on your property.
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My name is Andrew Liebetrau. I am an ISA Certified Arborist and do sales, estimates, and business development for Tree Wise Men. I've always loved the outdoors, always loved nature, and I was fortunate to have an opportunity to come work for this company and get into that field of work — helping people, helping the environment.
A typical workday for me is going to different sites, meeting with homeowners and business owners, and going over concerns they might have with certain trees on their property and how we might be able to help address those. It's thinking long-term about how we can improve as a company, how we can improve our footprint, and how we can work better for the customers we're serving.
Deciding whether or not we're going to remove a tree, cable a tree, or trim a tree — there's a lot of factors that come into play. Risk assessment is the biggest part. What level of risk is that tree posing? What level of risk is a homeowner comfortable with? Sometimes a tree may have signs of decay or be in a position where it could lose some limbs, but where is that tree located? If it's far away from a house, if there's not anything around there, we have conversations with homeowners to find out what their main concerns are and try to marry that with what we as arborists see as a risk or a situation where that tree might need to come down in order to be safe.
A lot of times it's aesthetics. Homeowners have a certain look that they want for their property and their trees, and that can vary greatly from person to person. So we try to blend those things together with what's going to be best for that tree and for that site.
We will get requests to top trees — to just cut the height off, chop it down at the top to reduce that height. As arborists, we know that's going to cause risks for that tree. It's going to open it up to insect issues, disease issues, and it's just not something we recommend as arborists. So we try to talk through what that would do to that tree. Essentially it's harming the tree and putting it in a position where it's going to fail over time. We really try to have that conversation with homeowners — topping a tree just isn't something we do in practice as arborists.
The biggest challenge we face is accessibility. How are we going to get to a tree? How are we going to get those materials out of there as the tree comes down? Often it's something you don't know until you're there and you see that terrain is a challenge.
When you've got a tree close to your home, you want to look for signs of decay. Look for how close that tree is to your roof, to your structure, and what that tree is doing in heavy weather — rain, snow. Is it touching your roof? Is it getting close? Just kind of look for those signs and consider having an arborist come look to see if something needs to be addressed.
Every day for an arborist looks very different. As a homeowner or business owner, when you have issues you think might exist with your trees, or you just have questions or concerns, getting in touch with a Certified Arborist is the best first step to find out if and what might need to be addressed.
What Makes an ISA Certified Arborist Different?
Anyone can buy a chainsaw and call themselves a tree service. An ISA Certified Arborist has demonstrated mastery of the science behind tree care. Here's what sets them apart:
Tree Biology & Science
Certified arborists understand how trees grow, how they respond to pruning, and what causes decline. This knowledge prevents improper cuts that can harm or kill trees.
Proper Pruning Techniques
Following ANSI A300 standards, our arborists make precise cuts that promote healthy growth — not the topping, flush cuts, and over-pruning that damage trees.
Disease Diagnosis & Treatment
From oak wilt to emerald ash borer, our arborists can identify tree diseases and pests early and recommend effective treatment plans before it's too late.
Ongoing Education
ISA certification requires 30 continuing education units every 3 years. Our team stays current with the latest research, treatments, and best practices.
Risk Assessment (TRAQ)
Our TRAQ-certified arborists use standardized methodology to evaluate tree risk — determining the likelihood of failure and potential consequences.
Ethical Tree Care
Certified arborists follow a code of ethics. We'll never recommend removing a healthy tree for profit or perform unnecessary work. We educate, then let you decide.
Certified Arborist vs. Uncertified Tree Service
ISA Certified Arborist
- Follows ANSI A300 pruning standards
- Can diagnose diseases and recommend treatments
- Understands tree biology and growth patterns
- Carries verified insurance and credentials
- Provides written assessments and reports
- Maintains certification through continuing education
- Will recommend preservation over removal when possible
Uncertified Tree Service
- ✗May top trees or make improper cuts
- ✗Cannot diagnose tree health issues
- ✗May not understand how trees respond to pruning
- ✗Insurance status may be unverified
- ✗Rarely provides written documentation
- ✗No requirement for ongoing training
- ✗May recommend unnecessary removals for profit
Meet Our Certified Arborists
Every arborist on our team holds current ISA certification and brings specialized expertise to your tree care project.
Jason James
President & Founder
Jason founded Tree Wise Men LLC in 2010 with the vision of bringing professional, certified arborist services to Janesville and Southern Wisconsin. He oversees every aspect of company operations — from complex tree removals to long-term tree health plans for residential and commercial properties.
Read full bio →Andrew Christl
Operations Manager
Andrew is responsible for coordinating crew schedules, managing project logistics, and ensuring every job site in Janesville, Madison, and the surrounding areas runs safely and efficiently. On any given day he's juggling multiple crews, equipment dispatch (cranes, grapple saw trucks, chippers, stump grinders), and the unpredictable timing that comes with storm-response work.
Read full bio →Andrew Liebetrau
Sales Lead
Andrew leads sales and estimates business development for Tree Wise Men. Before entering arboriculture, he built his career in radio advertising — work that gave him strong communication and client-relationship skills. A love for the outdoors drew him to tree care, and ISA certification turned that passion into expertise.
Read full bio →Mark Tyler Schrader
Grapple Saw & Crane Operator
Mark is Tree Wise Men's specialist in heavy equipment operations. He holds ISA Certified Arborist credentials alongside his Certified Crane Operator certification and CDL Class A license — a combination of arborist knowledge and heavy equipment expertise that's relatively rare in the industry and absolutely essential for crane-assisted tree removal of large canopy trees over homes, power lines, and structures.
Read full bio →Certified Arborist FAQs
What is an ISA Certified Arborist?
An ISA Certified Arborist is a tree care professional who has passed the International Society of Arboriculture's comprehensive exam and maintains their certification through continuing education. The exam covers tree biology, diagnosis, pruning, safety, soil science, and urban forestry.
Why should I hire an ISA Certified Arborist?
ISA Certified Arborists have demonstrated knowledge of tree biology, proper pruning techniques, disease diagnosis, and safety standards. Hiring a certified arborist means your trees are cared for by someone who understands how trees grow and how to keep them healthy — not just someone with a chainsaw.
What is TRAQ certification?
Tree Risk Assessment Qualification (TRAQ) is an advanced certification that trains arborists to systematically evaluate tree risk using a standardized methodology. TRAQ-certified arborists can assess the likelihood of tree failure, the consequences, and recommend appropriate mitigation strategies.
How do I verify an arborist's ISA certification?
You can verify any arborist's certification on the ISA website at treesaregood.org. Ask for their certification number and look them up. All Tree Wise Men LLC arborists maintain current ISA certification with ongoing continuing education credits.
What continuing education do your arborists complete?
ISA Certified Arborists must earn 30 continuing education units (CEUs) every three years to maintain certification. Our team attends industry conferences, participates in TCIA training programs, and completes coursework in emerging topics like oak wilt management and emerald ash borer treatment.
Get Expert Tree Care from Certified Arborists
Schedule a consultation with our ISA Certified Arborists. We'll assess your trees, answer your questions, and provide honest recommendations.