Disease and insect pathogens such as Chestnut Blight, Dutch Elm Disease, and Emerald Ash Borer have made headlines for over a century, but a far greater problem exists for our urban forests and that is – deep planting.

The issue of deep planting is a human-made problem that can impact any tree planted. Tree health concerns such as stem girdling roots and basal trunk rot happen when the tree trunk is placed too deep into the soil during final planting in the landscape.

Legacy-Trees aspires to change all that with our revolutionary production methods and transplant system.

Legacy-Trees has created a system of producing trees that works in concert with the tree’s root system to mimic how tree roots grow in the forest.



Ronald Zillmer

President and Founder


Zachary Zillmer

Research and Development


Jake Lewis

Production Manager


Allison Zillmer

Operations Manager


Mission Statement

Our mission at Legacy-Trees is to bring tree planning, diversity, proper planting, and stewardship to our urban ecosystems through a revolutionary system of growing and transplanting trees that will live for generations.

What Makes Legacy Unique

Legacy-Trees is a system of producing trees that works in concert with the tree’s root system to mimic how tree roots grow in the forest – unlike traditional nursery production and planting procedures that ignore this critical moment in the development of the root system. Roots are forced to grow within containers that are narrow and deep. This is done to facilitate shipping and handling rather than proper root orientation for long term survival. The traditional systems of production and planting rely on the tree and its root system to recover from damage after planting at your property. This, combined with deep planting, causes most trees to struggle to establish new roots on the site. Many die early in their life span instead of thriving for over 100 years! The primary structural roots of the tree are supposed to radiate from the root flare in all directions like the spokes of a wheel. The Legacy system encourages this natural root development and delivers a balanced root system that is ready to immediately colonize your property.

We’ve created a system of production and transplanting to bring you a superior tree that will provide beauty for generations to come.


Who is Ron Zillmer?

The story of Legacy-Trees founder and President, Ron Zillmer, begins in the woods as a young boy. Ron spent his childhood outdoors walking through the forest with his dog, Tippie. He is someone that was drawn to the forest from the beginning of his life and wanted to take that passion and make it into a career. This brought him to the University of Wisconsin – Stevens Point where he began an undergraduate degree in traditional forestry. His path changed rapidly when he met Dr. Robert Miller who was the professor of Urban Forestry at Stevens Point and changed the trajectory of Ron’s degree to an emphasis in urban forestry rather than traditional forestry. The fall of 1988 is when Ron’s passion for understanding how trees grow beneath the soil began. He assisted Dr. Alex Shigo with his Tree Biology Workshop at the UWSP Treehaven Facility in northern Wisconsin. From there he got to witness Dr. Shigo walk up to a tree with a defect on the outside and tell him exactly what was wrong on the inside. This is where Ron’s inspiration to understand trees from the inside out began.

Upon completion of his undergraduate degree at UW — Stevens Point, Ron was presented with a once in a lifetime opportunity to attend graduate school at Purdue University under the supervision of Dr. William Chaney, a Tree Physiologist. Thus, Ron’s work at Purdue began as he worked towards a master’s degree in tree physiology. Dr. William Chaney, Dr. Harvey Holt, and Dr. Robert Joly were the three primary members involved on his committee as he worked on his thesis project titled ‘The Structural and Biological Effects of Trunk Injected Paclobutrazol in Liriodendron tulipifera.’ From there, Ron’s interests in the structural defects of tree root systems grew further. As he continued his education his mind remained around one concept Dr. Shigo told him during his time at Stevens Point, “90 percent of what we know about trees is above ground, yet 90 percent of trees problems start underground.”

When Ron completed his master’s degree in forestry in May of 1991, he began working for the Municipal Urban Forestry Program in Milwaukee, Wisconsin as the Forestry Technical Services Coordinator and later became the Urban Forestry Manager. When he arrived in Milwaukee, he was asked to investigate why most of the 200,000 street trees in Milwaukee were dying. While others looked up, he looked down and realized that over 90% of the trees were planted 6 to 12 inches too deep in the ground. This was the first moment where the foundation of Legacy-Trees was planted in Ron’s mind. From Ron’s extensive work at Milwaukee and word getting out about his planting and root system discoveries, Ron and a colleague, Dan Traas, a UWSP graduate who owns Ranger Services in Appleton, Wisconsin, created a seminar titled ‘Twenty Minutes in the Life OR Death of a Tree’. Over the years this seminar has been presented in at least 20 states and 3- countries taking Ron as far as Hong Kong to present in 2005.

From Ron’s work in proper tree planting, he was elected to the board of the Wisconsin Arborist Association and was elected President in 1995. At the time, he was the youngest President to be elected by the WAA. Ron was asked to serve on the International Society of Arboriculture’s – Arborist Certification Board that was creating a unified system of certification for arborists around the world. During his 6 years on the board, the number of certified arborists went from 2,000 to 20,000 and truly became an international program. From there, Ron joined Mid-State Technical College out of Wisconsin Rapids to build a 2+2 Urban Forestry Technician Degree that laddered into a four-year degree at UW Stevens Point. Ron spent nearly 20 years at Mid-State where he taught Urban Forestry and eventually moved on to become a manager to oversee the program, he created along with managing other programs.

One area that sparked Ron’s interest was apprenticeship and the journeyman worker system. Ron landed a grant for developing the Arborist Apprenticeship Program. It took him and his fellow colleagues three years to complete it and went live in 2016. It was then submitted to the Federal Department of Labor where it was adopted as the model for the national program. Through his extensive work to develop this program, Ron was awarded by the Tree Care Industry Association with their National – Advancing Arboriculture award in 2017 in recognition of the Arborist Apprentice Program he built and for what he had done in creating training programs at the two-year college level.

The question remains. Who is Ron Zillmer? To me, he is my dad. He is the crazy tree guy who would take my brother, dog, and me to the woods from the time we could walk. I have never truly understood the magnitude of his work in the tree care industry, but I have always understood his love for the outdoors. In 2017, when Legacy-Trees was born, I worked for him and managed his very first nursery which was planted in 2019. That was my first glimpse into his world, and I couldn’t get enough. I am now the Operations Manager at Legacy-Trees and am learning alongside all the customers and companies we are bringing on to be apart of our mission to plant trees that will live on for generations. Will you join us in planting a living legacy through trees?

~ Allison Zillmer

Operations Manager with Legacy-Trees