Leadership Team

Our Leadership Team is committed to making Yellowstone Landscape the country’s premier commercial landscape service company and to bringing that excellence to bear on behalf of our clients through industry-leading investments in safety, training, information systems, and execution.

Harry Lamberton

Harry Lamberton

President & Chief Executive Officer

Harry Lamberton was named President and CEO of Yellowstone Landscape in May of 2023, after joining Yellowstone in January of 2022 as President. As CEO, Harry leads and drives Yellowstone’s strategy, continued growth, quality service, focus on safety, and maintaining a great place to work for all employees, applying expertise gained from over 20 years of leading environmental and sustainability businesses at Waste Management.  Harry continues to be active in broadly supporting sustainability and the environment by serving on the Conference Board’s Global Sustainability Centre’s Advisory Board, the Board of Directors of the Sustainability Institute at the University of New Hampshire and the Board of Directors of Friends of the Chicago River.  Harry holds a BA from the University of New Hampshire and an MBA from the Goizueta School of Business at Emory University.

Harry Lamberton

Harry Lamberton

President & Chief Executive Officer

Harry Lamberton was named President and CEO of Yellowstone Landscape in May of 2023, after joining Yellowstone in January of 2022 as President. As CEO, Harry leads and drives Yellowstone’s strategy, continued growth, quality service, focus on safety, and maintaining a great place to work for all employees, applying expertise gained from over 20 years of leading environmental and sustainability businesses at Waste Management.  Harry continues to be active in broadly supporting sustainability and the environment by serving on the Conference Board’s Global Sustainability Centre’s Advisory Board, the Board of Directors of the Sustainability Institute at the University of New Hampshire and the Board of Directors of Friends of the Chicago River.  Harry holds a BA from the University of New Hampshire and an MBA from the Goizueta School of Business at Emory University.

Timothy Sherman

Timothy Sherman

Chief Financial Officer

Timothy (Timo) Sherman serves as Chief Financial Officer of Yellowstone Landscape with oversight over all Finance, Accounting, IT, and Procurement functions. He has led the financial analysis team since 2018, focusing on excellence in planning, forecasting, budgeting, analysis, acquisition planning, due diligence, closing and initial integration management, and any other areas requiring financial evaluation and insight. He first worked in landscaping as a construction project manager, then account manager and branch manager for Cornerstone Landscape, which was acquired by Yellowstone in 2012. He later moved from field management into finance, becoming one of Yellowstone’s first regional field financial analysts in 2015. He is motivated to deliver the same excellence and rigor in the financial support functions that customers demand from Yellowstone’s talented crews on their properties. Timo holds a BS from the Fisher School of Accounting at the University of Florida and an MBA from Jacksonville University and has experience in Staff and Cost Accounting.

Timothy Sherman

Timothy Sherman

Chief Financial Officer

Timothy (Timo) Sherman serves as Chief Financial Officer of Yellowstone Landscape with oversight over all Finance, Accounting, IT, and Procurement functions. He has led the financial analysis team since 2018, focusing on excellence in planning, forecasting, budgeting, analysis, acquisition planning, due diligence, closing and initial integration management, and any other areas requiring financial evaluation and insight. He first worked in landscaping as a construction project manager, then account manager and branch manager for Cornerstone Landscape, which was acquired by Yellowstone in 2012. He later moved from field management into finance, becoming one of Yellowstone’s first regional field financial analysts in 2015. He is motivated to deliver the same excellence and rigor in the financial support functions that customers demand from Yellowstone’s talented crews on their properties. Timo holds a BS from the Fisher School of Accounting at the University of Florida and an MBA from Jacksonville University and has experience in Staff and Cost Accounting.

Tim new

Tim Portland

Executive Chairman

Tim Portland has led Yellowstone Landscape to record safety, customer satisfaction, growth, and overall business performance since joining the company in 2012 as CEO. In May of 2023, he moved to Executive Chairman, where he is highly active and engaged within the company and supporting the company’s executive leadership. In addition to Chairing Yellowstone’s Board of Directors, Tim serves on the Board of Directors of the National Association of Landscape Professionals and chairs the association’s H-2B steering committee. He also serves on the Board of the Seasonal Employment Alliance, an advocacy organization focused on congressional reform of the guest worker visa programs that sustain seasonal businesses across the United States. Prior to joining Yellowstone, Tim was the CEO of United Subcontractors, a leading installer of building products. Over a ten-year period, he was the President of several divisions of Scotts Miracle-Gro, including the Ortho and Roundup brands, Scotts LawnService, and Scott’s International Professional business. He was previously an executive with Scientific-Atlanta (now part of Cisco), and a management consultant with McKinsey and Company. Tim holds an MBA from the University of Virginia’s Darden Business School and an undergraduate degree from Dartmouth College.

Tim new

Tim Portland

Executive Chairman

Tim Portland has led Yellowstone Landscape to record safety, customer satisfaction, growth, and overall business performance since joining the company in 2012 as CEO. In May of 2023, he moved to Executive Chairman, where he is highly active and engaged within the company and supporting the company’s executive leadership. In addition to Chairing Yellowstone’s Board of Directors, Tim serves on the Board of Directors of the National Association of Landscape Professionals and chairs the association’s H-2B steering committee. He also serves on the Board of the Seasonal Employment Alliance, an advocacy organization focused on congressional reform of the guest worker visa programs that sustain seasonal businesses across the United States. Prior to joining Yellowstone, Tim was the CEO of United Subcontractors, a leading installer of building products. Over a ten-year period, he was the President of several divisions of Scotts Miracle-Gro, including the Ortho and Roundup brands, Scotts LawnService, and Scott’s International Professional business. He was previously an executive with Scientific-Atlanta (now part of Cisco), and a management consultant with McKinsey and Company. Tim holds an MBA from the University of Virginia’s Darden Business School and an undergraduate degree from Dartmouth College.

James Herth (1)

James Herth

Senior Vice President, Business Development

Jim Herth became Yellowstone Landscape’s Vice President of Business Development in 2014, after joining the company in 2011 as a Branch Manager. “Coach” Jim is responsible for Yellowstone’s industry-leading sales team, a critical component of Yellowstone’s superior growth and track record with customers. A twenty-five-year industry veteran with a track record of managing multiple branches, delighting customers, and delivering profitable growth, Jim is a licensed Arborist and holds a Bachelor’s degree from Siena Heights University.

James Herth (1)

James Herth

Senior Vice President, Business Development

Jim Herth became Yellowstone Landscape’s Vice President of Business Development in 2014, after joining the company in 2011 as a Branch Manager. “Coach” Jim is responsible for Yellowstone’s industry-leading sales team, a critical component of Yellowstone’s superior growth and track record with customers. A twenty-five-year industry veteran with a track record of managing multiple branches, delighting customers, and delivering profitable growth, Jim is a licensed Arborist and holds a Bachelor’s degree from Siena Heights University.

Brian Wester (1)

Brian Wester

Senior Regional Vice President

Brian Wester is Yellowstone Landscape’s Senior Vice President of Operations, responsible for the company’s operations across the Southeast United States. Brian joined the company in 2003 as an Account Manager in Palm Coast, Florida. He launched and managed multiple branch locations across Central Florida before being promoted to Regional Vice President in 2011. He led the post-recession turnaround of the company’s Georgia and South Carolina operations and has since returned to Florida, now leading operations across three states for Yellowstone. Brian holds an Associate of Science degree in Golf Course Operations, a Bachelor of Science degree in Business and Finance, and earned his MBA from the University of Florida.

Brian Wester (1)

Brian Wester

Senior Regional Vice President

Brian Wester is Yellowstone Landscape’s Senior Vice President of Operations, responsible for the company’s operations across the Southeast United States. Brian joined the company in 2003 as an Account Manager in Palm Coast, Florida. He launched and managed multiple branch locations across Central Florida before being promoted to Regional Vice President in 2011. He led the post-recession turnaround of the company’s Georgia and South Carolina operations and has since returned to Florida, now leading operations across three states for Yellowstone. Brian holds an Associate of Science degree in Golf Course Operations, a Bachelor of Science degree in Business and Finance, and earned his MBA from the University of Florida.

Blake Singleton

Blake Singleton

Senior Regional Vice President, Mid-Atlantic Region

Blake Singleton joined Yellowstone Landscape in 2016 as Director of North Carolina Maintenance Operations when Yellowstone expanded to the state. Blake previously held account, branch, sales, and regional management positions for other highly respected landscape firms. Since becoming Yellowstone’s Mid-Atlantic Regional Vice President, Blake has further led Yellowstone’s growth across the region, and now manages branch locations spanning 6 states. Blake holds a Bachelor of Science in Business and Economics from the University of South Carolina Upstate.

Blake Singleton

Blake Singleton

Senior Regional Vice President, Mid-Atlantic Region

Blake Singleton joined Yellowstone Landscape in 2016 as Director of North Carolina Maintenance Operations when Yellowstone expanded to the state. Blake previously held account, branch, sales, and regional management positions for other highly respected landscape firms. Since becoming Yellowstone’s Mid-Atlantic Regional Vice President, Blake has further led Yellowstone’s growth across the region, and now manages branch locations spanning 6 states. Blake holds a Bachelor of Science in Business and Economics from the University of South Carolina Upstate.

Jim Sivils

Jim Sivils

Regional Vice President, Texas

Jim Sivils joined Yellowstone Landscape in 2010 after 20 years of owning and operating Texas Services – one of Houston’s most successful tree and landscape services companies. Jim has overseen Yellowstone’s extraordinary growth in Texas and is responsible for all Yellowstone Landscape operations across the state.

Jim Sivils

Jim Sivils

Regional Vice President, Texas

Jim Sivils joined Yellowstone Landscape in 2010 after 20 years of owning and operating Texas Services – one of Houston’s most successful tree and landscape services companies. Jim has overseen Yellowstone’s extraordinary growth in Texas and is responsible for all Yellowstone Landscape operations across the state.

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Jeff Kelly

Regional Vice President, Midwest

Jeff Kelly joined the company in 2020 as Yellowstone expanded to the Midwest through the acquisition of Acres Group. Jeff had been a part of Acres since 1997, ascending in roles from Vice President of Construction Operations to Vice President of Operations, and his immediate prior role as President. Since joining Yellowstone, Jeff's deep experience in both landscape operations and snow and ice management have proven invaluable as Yellowstone has expanded into new markets across the Midwest. Jeff earned an Associate Degree in Horticulture from Illinois Central College and his Bachelor of Science degree from Southern Illinois University in Plant and Soil Science.
Jeff Kelly-navy bg

Jeff Kelly

Regional Vice President, Midwest

Jeff Kelly joined the company in 2020 as Yellowstone expanded to the Midwest through the acquisition of Acres Group. Jeff had been a part of Acres since 1997, ascending in roles from Vice President of Construction Operations to Vice President of Operations, and his immediate prior role as President. Since joining Yellowstone, Jeff's deep experience in both landscape operations and snow and ice management have proven invaluable as Yellowstone has expanded into new markets across the Midwest. Jeff earned an Associate Degree in Horticulture from Illinois Central College and his Bachelor of Science degree from Southern Illinois University in Plant and Soil Science.
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Jon Richardson

Regional Vice President, Southwest

Jon Richardson is among the longest-tenured members of the Yellowstone Landscape leadership team and is currently responsible for the company’s operations across the Southwestern United States. Jon joined the company in 1994 and has held a number of positions of ascending responsibility, including Vice President of Construction for our Texas region, immediately preceding his current role. His deep industry knowledge and experience continue to be demonstrated in his operational teams’ performance and his ability to mentor young and talented Landscape Professionals.

jon-richardson-green-bg

Jon Richardson

Regional Vice President, Southwest

Jon Richardson is among the longest-tenured members of the Yellowstone Landscape leadership team and is currently responsible for the company’s operations across the Southwestern United States. Jon joined the company in 1994 and has held a number of positions of ascending responsibility, including Vice President of Construction for our Texas region, immediately preceding his current role. His deep industry knowledge and experience continue to be demonstrated in his operational teams’ performance and his ability to mentor young and talented Landscape Professionals.

Elise Johnson (1)

Elise Johnson

Vice President, Human Resources

Elise Johnson has led Yellowstone Landscape’s Human Resources team needs since joining the company in 2010. Elise and her team are chiefly responsible for helping our local branch leaders find and recruit the talented and professional managers needed for continued strong growth and consistently excellent quality. She has also developed local support tools and implemented best practices for attracting and retaining frontline personnel, including benefits, rewards, and engagement programs designed to make Yellowstone the best place to work in the landscape industry. She navigates the company’s seasonal operating demands and decentralized business structure while ensuring regulatory compliance within a demanding, performance-driven culture. Elise earned a BA from Dickinson College and her MBA from Rutgers, The State University of New Jersey. Before joining Yellowstone, Elise held similar positions at prominent financial services firms in New York City.

Elise Johnson (1)

Elise Johnson

Vice President, Human Resources

Elise Johnson has led Yellowstone Landscape’s Human Resources team needs since joining the company in 2010. Elise and her team are chiefly responsible for helping our local branch leaders find and recruit the talented and professional managers needed for continued strong growth and consistently excellent quality. She has also developed local support tools and implemented best practices for attracting and retaining frontline personnel, including benefits, rewards, and engagement programs designed to make Yellowstone the best place to work in the landscape industry. She navigates the company’s seasonal operating demands and decentralized business structure while ensuring regulatory compliance within a demanding, performance-driven culture. Elise earned a BA from Dickinson College and her MBA from Rutgers, The State University of New Jersey. Before joining Yellowstone, Elise held similar positions at prominent financial services firms in New York City.

Chris Adornetti (1)

Chris Adornetti

Senior Vice President, Accounting

Since joining Yellowstone Landscape in 2015, Chris Adornetti has overseen all day-to-day Accounting and Finance operations of the company, including all treasury, insurance, tax, and legal requirements. Prior to joining Yellowstone, Chris spent 7 years at Harte Hanks, a publicly-traded marketing, data analytics, and logistics company, and previously worked in public accounting and internal audit. A two-time graduate of the University of North Florida, Chris holds a Bachelor’s degree in Accounting and a Master’s in Business Administration.

Chris Adornetti (1)

Chris Adornetti

Senior Vice President, Accounting

Since joining Yellowstone Landscape in 2015, Chris Adornetti has overseen all day-to-day Accounting and Finance operations of the company, including all treasury, insurance, tax, and legal requirements. Prior to joining Yellowstone, Chris spent 7 years at Harte Hanks, a publicly-traded marketing, data analytics, and logistics company, and previously worked in public accounting and internal audit. A two-time graduate of the University of North Florida, Chris holds a Bachelor’s degree in Accounting and a Master’s in Business Administration.

Gabe Perez (1)

Gabe Perez

Vice President, IT and Business Systems

Since joining Yellowstone Landscape in 2018, Gabe Perez has been responsible for the company’s critical technology infrastructure and systems. With a background in programming, quality assurance, and business intelligence, Gabe and his team deliver the most efficient and user-friendly information systems and reporting possible. Leaders at all levels of the company rely on the work of Gabe’s team when making decisions about how to best manage their parts of the business and drive the overall performance of the company. A native of Flagler County, Florida, Gabe completed his Associate’s degree at the University of South Florida before earning his Bachelor of Science in Information Technology and Management at Keiser University in Jacksonville.

Gabe Perez (1)

Gabe Perez

Vice President, IT and Business Systems

Since joining Yellowstone Landscape in 2018, Gabe Perez has been responsible for the company’s critical technology infrastructure and systems. With a background in programming, quality assurance, and business intelligence, Gabe and his team deliver the most efficient and user-friendly information systems and reporting possible. Leaders at all levels of the company rely on the work of Gabe’s team when making decisions about how to best manage their parts of the business and drive the overall performance of the company. A native of Flagler County, Florida, Gabe completed his Associate’s degree at the University of South Florida before earning his Bachelor of Science in Information Technology and Management at Keiser University in Jacksonville.

Ben Collinsworth

Ben Collinsworth

Director of Advanced Technologies & Sustainability

Ben Collinsworth joined the company in 2019 and serves as Director of Advanced Technologies and Sustainability at Yellowstone Landscape. In his role, Ben is focused on expanding and implementing new technologies into the company’s operations. These include both software and systems, tools and capabilities, and leading the testing and field practices for new advances in autonomous and robotic mowing opportunities and battery and electric-powered devices. In May of 2023, Ben’s role expanded to include oversight of the company’s efforts to promote sustainability within our client properties, the company, and the landscape industry. Prior to joining Yellowstone, he founded and managed his own successful commercial landscaping company for more than 20 years, Native Land Design, operating locations in both Austin and Houston, Texas. Ben is a proud graduate of Texas A&M University, where he played defensive end on the A&M football team.

Ben Collinsworth

Ben Collinsworth

Director of Advanced Technologies & Sustainability

Ben Collinsworth joined the company in 2019 and serves as Director of Advanced Technologies and Sustainability at Yellowstone Landscape. In his role, Ben is focused on expanding and implementing new technologies into the company’s operations. These include both software and systems, tools and capabilities, and leading the testing and field practices for new advances in autonomous and robotic mowing opportunities and battery and electric-powered devices. In May of 2023, Ben’s role expanded to include oversight of the company’s efforts to promote sustainability within our client properties, the company, and the landscape industry. Prior to joining Yellowstone, he founded and managed his own successful commercial landscaping company for more than 20 years, Native Land Design, operating locations in both Austin and Houston, Texas. Ben is a proud graduate of Texas A&M University, where he played defensive end on the A&M football team.

Brian Martin (1)

Brian Martin

Vice President, Standards, Safety, and Training

With nearly thirty years of experience in the commercial landscaping industry, Brian Martin has performed several leadership roles for Yellowstone, including prior line management of all of Yellowstone’s Florida operations. To help meet the demands of Yellowstone’s rapid growth, Brian took on leadership of Yellowstone’s Standards, Safety, and Training needs. He is responsible for developing and applying the best practices of the company across varied regions and branch locations while continuing to increase operational efficiency and quality. Through his dedicated Health and Safety team, the company has achieved some of the lowest incident rates in the landscape industry and is routinely recognized for the proactive approach that Yellowstone takes toward safety and protecting its employees, clients, and their properties. Brian personally leads employee training and development for Branch Managers, Account Managers, Irrigators, and other Horticultural Personnel. Brian is a graduate of Virginia Tech’s Landscape Architecture program and holds an MBA from the University of Florida.

Brian Martin (1)

Brian Martin

Vice President, Standards, Safety, and Training

With nearly thirty years of experience in the commercial landscaping industry, Brian Martin has performed several leadership roles for Yellowstone, including prior line management of all of Yellowstone’s Florida operations. To help meet the demands of Yellowstone’s rapid growth, Brian took on leadership of Yellowstone’s Standards, Safety, and Training needs. He is responsible for developing and applying the best practices of the company across varied regions and branch locations while continuing to increase operational efficiency and quality. Through his dedicated Health and Safety team, the company has achieved some of the lowest incident rates in the landscape industry and is routinely recognized for the proactive approach that Yellowstone takes toward safety and protecting its employees, clients, and their properties. Brian personally leads employee training and development for Branch Managers, Account Managers, Irrigators, and other Horticultural Personnel. Brian is a graduate of Virginia Tech’s Landscape Architecture program and holds an MBA from the University of Florida.

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