The Leadership

at the Dubuque Arboretum & Botanical Gardens


The Dubuque Arboretum & Botanical Gardens

To establish, preserve, and maintain an arboretum and botanical garden that is a source of information, education, culture, and beauty for all to know.



Steve Ulstad, AIA (Ulstad Architects), has provided professional services (Architecture, Landscape Design, Interior Design) to the Dubuque area since 1982.

Married to Jane for 45 years, they have four grown children and seven active grandchildren.

Beginning in the mid-80s, my family and I would visit the Arboretum’s grounds often. Then, after Jack Frick invited me to join the Garden Club, I followed him to join the Dubuque Arboretum & Botanical Gardens. I was soon swallowed up in all of the activities! Later, I created the Planning Committee to discuss planning issues and take some of the stress off the Board’s monthly activities. We have continued to maintain and build upon the original gardens and have created several new gardens: Legacy Trees, Garden of Eat’n, and the Allé, Herb Garden, Cactus Garden. I’m looking forward to a bright future working with all of the wonderful volunteers and greeting visitors from Dubuque and around the world!”


JEFF MOZENA | Vice-Chair

Jeff Mozena is retired President/CEO, and current Chairman of the Board of Premier Bank, Dubuque, Iowa.

From my early days picking black raspberries on the Marshall farm and meeting Mac Marshall on his porch for a drink of well water, I knew his farm was unique … filled with trees and vegetation. I’m certain he would be pleased to see the beauty created in his memory. My uncle, Mel Gottschalk, assisted with the development of the Rose Garden and was active with the beginning of the gardens. Today we add to his legacy with the recent addition of the Edna Mozena Conifer Garden. The gardens provide a place of beauty to relax and enjoy nature. We welcome all to enjoy the work of the Dubuque Garden community.”


SUE SIMON | Secretary

Sue Simon is a retired executive, entrepreneur, and teacher with a career devoted to education and learning. Most recently of Simon and Kolz Publishing, Sue’s professional life has centered around books:  teaching, publishing, and retailing. 

For years I watched the Arboretum grow and develop into a special destination that provides value to all who visit. Joining the dedicated team of volunteers, responsible for the care and nurturing of the Arboretum, has been a privilege. I have been fortunate to know some individuals who were drivers of the Arboretum’s initial growth and experienced the enthusiasm and dedication of its strong volunteer-led stewardship. Serving on the Board and supporting the mission of the Arboretum as it provides the Dubuque community with a valuable resource offering nature education and enjoyment has been an honor. With the dedication of its volunteers, the support of the community, and strong leadership, I believe the DABG is poised to continue to expand its capacity to welcome all of Dubuqueland and the travelers who visit our city to enjoy some of nature at its best.



Marsha Abbott is a financial advisor with Edward Jones Investments in Dubuque, Iowa. Prior to working at the firm, she graduated summa cum laude and earned her Bachelor of Arts degree in both finance and real estate at the University of Northern Iowa.

Residing in Dubuque with her husband, Brad, and their three children, Lexy, Gavin and Claire, they enjoy skiing, watching movies, and just spending time together as a family. 

Over the years, my family and I have enjoyed many quiet walks through the Arboretum. Every time I am here, a certain sense of peace and tranquility washes over me. I am honored to have been chosen to help on the board as it allows me to give back to the community in a way that I feel will leave a beautiful legacy for future generations to come.”


WYLIE BLEDSOE | Board Member

During Wylie Bledsoe’s work life, he had been a supervisor at Mercury Marine for 43 years and had enjoyed fixing machinery and keeping things running. He and his wife, Jean, relocated to Dubuque when he retired in 2005, as they enjoyed the area and the people. 

I enjoy being on the Board of Directors to help with the continuing development and growth of the Arboretum. It has been my honor to work on projects throughout the Arboretum and I’ve enjoyed working with many of the volunteers and being a helper when asked.”


MEL GRAVES | Board Member

Mel Graves was born in Cleveland, Ohio, raised in Pocatello, Idaho, and went to college in Baltimore, Maryland, and Chicago, Illinois. He came to Dubuque in 1976 and has lived and worked here since, including 32 years as a REALTOR with Brissey Realty. Mel has served on the DABG board since 1995 and was Treasurer 18 of those years.

Working at and for the DABG has been and remains both a challenge and very rewarding. I have seen our DABG grow from a lovely set of gardens in 1995 to the exceptional natural museum it is today. During that time hundreds of volunteers have researched, planned, built and maintained the DABG to the treasure we see today. Of course, this was not accomplished without the help of overwhelming support from thousands of donations of time, capital and gifts of plants & equipment from Dubuque area businesses, individuals and city, county, state and private grants, and significant legacy gifts. It has been a terrific experience for me. I remain amazed that we have never had to charge anyone an admission fee!”


MERLIN GREEN | Board Member

Merlin Green grew up on a farm in southwest Minnesota, learning to drive a tractor at the age of 5!

After completing a degree in Agricultural Engineering at the University of Minnesota, he and his wife Jo moved to Dubuque where Merlin began his employment at the John Deere Dubuque Works in the product engineering department. Most of his career involved developing software for the rapid analysis of field test data.

My volunteering at the DABG started with taking over the project of mapping and inventorying our trees and plants in the gardens. That work continues, but the computer background has evolved into the support and development of much of the office and gift shop software and processes.

For me, the Dubuque Arboretum has become a ‘haven’ where the beauty and peacefulness fulfill many personal needs.”


LYNNE HAGER | Board Member

Lynne Hager is Vice President of Marketing at MidWestOne Bank.

Whether you’re having a good or a bad day, I promise that visiting the Arboretum will put a smile on your face. A stroll through nature always seems to make everything better. During my tenure on the board, it has been a joy watching the Arboretum bloom into what it is today. I truly believe our Arboretum is one of the best destinations in Dubuque!


DENNIS HOYER | Board Member

Dennis Hoyer worked at John Deere for 42 years in a number of capacities, including positions in the factory and the office. He managed many projects for the company and was the Product Line Manager for John Deere’s Motor Grader Line and the Materials Manager in Sweden for the Construction and Forestry Division.

The Arboretum is a special place for our family. We’ve had the privilege of living near the Arboretum for the last 18 years and have been fortunate to observe firsthand how many people enjoy this special place. When we have visitors, its high on their agenda to go through the Arboretum. With the direction of the Board and with participation of volunteers, we’ve seen great growth in the number of attractions the Arboretum provides and in the business of the Arboretum.”



JENNA HIRTZ | Director

Jenna Hirtz started as the second director for the Dubuque Arboretum & Botanical Gardens in the fall of 2021. Her previous work experience:

  • an Audit Associate at Eide Bailly LLP, and
  • a Budget Financial Analyst with the City of Dubuque.

Her schooling began at Northeast Iowa Community College, where she earned an Associate’s degree in Accounting. She then transferred to the University of Dubuque where she completed a Bachelor’s in Accounting, Business, and Human Resource Management as well as a Master of Business Administration.

I have been coming to the Dubuque Arboretum since I was a little girl and have many fond memories here. Being able to create cherished memories for others as they visit our beautiful grounds is something I enjoy. I love working in a role where I get to use my skills to help build a beautiful environment that is making a difference in our community, our ecosystem, and the lives of our guests.”


BARB BLOCK | Volunteer Coordinator

A Clarke University business graduate, Barb Block’s past work experience includes: Auxiliary Manager at NICC, Senior Media Manager at McGraw-Hill, Event and Fundraiser Coordinator and Bookkeeper at Tri-State Christian School.

I live in the caretaker house now, but I grew up on a small farm that shared the fence line with Mac Marshall. We traversed the hills of Union Park and Mac’s farm as children, and now the back part of my father’s farm is actually part of the Arboretum! I feel like I’m home, but with the benefit of having a beautiful ‘back yard’ to roam in! As Volunteer Coordinator, I enjoy collaborating with all the volunteers and love walking through the Arboretum in its various beautiful seasons. Please stop in and say HELLO!”