Leadership

Andrew leads the entire Arboretum organization, including more than 200 full-time, part-time and seasonal employees. Selected as the Arboretum’s director in 2023, he works collaboratively to create and implement a long-term vision and strategic plan for the Arboretum. Building on the strong foundation of the organization's first 65 years, Andrew is working to make the Arboretum a garden for all Minnesotans for generations to come.

Previously, Andrew served for 10 years as the Director of Horticulture at the Arnold Arboretum at Harvard University in Boston, caring for the plant collections and landscapes of North America’s oldest public arboretum. He was a founding member of the Arboretum’s Diversity, Inclusion and Belonging Committee, a leader in domestic and international plant collecting expeditions, and served as project lead for grounds capital improvements across the 281 acres.

Andrew’s past positions include roles at the Arboretum at Penn State in University Park, Pennsylvania and the Morton Arboretum in Lisle, Illinois. He earned his master’s in Public Horticulture from the University of Delaware in Newark, as part of the Longwood Gardens Graduate Program. Having grown up in the Milwaukee area — and earning his bachelor’s degree in Horticulture from the University of Wisconsin-Madison — Andrew is thrilled to return to the Midwest to lead an institution he has admired since his horticultural beginnings.

He lives with his wife and two children in the west-metro area of the Twin Cities. His favorite Minnesota-native tree is bur oak (Quercus macrocarpa).

Matthew is proud to coordinate an extraordinarily hard-working team of researchers at the Arboretum’s Horticultural Research Center (HRC), striving daily to identify new plant varieties to spark new industries, support farmers around the globe, bring exciting new fruits to market and to beautify landscapes. Research at the HRC also focuses on plant conservation to protect Minnesota’s rare and endangered plants for generations to come.

Since its inception in 1908, the HRC has generated more than 160 fruit and woody plant introductions, such as the Honeycrisp and SweeTango apples, the Itasca grape, Northern Lights azaleas, ornamental redbud trees and many others. 

Matthew has a Ph.D. and a master’s in Applied Plant Sciences (Plant Breeding and Genetics), both from the University of Minnesota, and a bachelor’s in Psychology from St. John’s University in Collegeville, Minnesota.

Also serving as an Associate Professor of Grape Breeding and Enology (2015-2022) and Fruit Breeding (presently) at the University of Minnesota, Matthew is an expert in using both traditional and molecular plant-breeding approaches to develop improved grape cultivars for cold-climate wine production. He’s studied the genetics behind the unique resistances to common grapevine pests — powdery mildew and phylloxera in hybrid germplasm — to help develop new grape varieties with multiple resistances to reduce the amounts of pesticides applied in a season. The Triumph apple, for example, was developed with sustainability in mind, as it has two forms of resistance to fungus that causes apple scab.

Matt teaches both undergraduate and graduate classes. For several years, he has taught “HORT 1001: Plant Propagation.” Learning about grafting, which is part of the class, was what inspired Matt to shift to a career in horticulture, and it remains his favorite topic to teach to students.

He lives in Hopkins with his partner Dan and their wiley Irish terrier Duncan. His favorite plant for Minnesota gardens currently is the Eastern hemlock because of its adaptability and form.

Rachelle works closely with the Executive Director and other Arboretum leaders to provide strategic leadership in facilities and project management, space planning, and safety and security across the Arboretum's geographically distinct areas. As part of her role, she serves as the liaison to University units, including the offices of Planning, Space, and Real Estate; Capital Project Management; and Public Safety.

In the years ahead, Rachelle will play a lead role in the planning and implementation of the Arboretum's PACE (Parking, Access, and Egress) project. A component of the 2018 Master Plan, the project will increase safe access to the Arboretum in alignment with concurrent Highway 5 improvements, along with a new main Arboretum entrance, gatehouse and entry experience. PACE will also expand visitor parking, improve circulation and include a new AppleHouse for expanded programming and retail operations — with a target completion date of 2027.

Rachelle has an extensive background in designing and managing public spaces, integrating both practicality and a strong sense of art, beauty and community into her work. She came to the Arboretum in 2024 from a role as Project Manager and Construction Coordinator for the City of Farmington, New Mexico.

Committed to inclusive design, Rachelle brings a wealth of community engagement experience. She previously worked with a youth workforce development organization, DownCity Design, where she gave high schoolers skills in design thinking and tools to put their ideas into practice through the creation of real community spaces. Other past experience includes work with a nonprofit housing developer, West Elmwood Housing, on developing safe and comfortable apartment spaces from the ground up for recently resettled refugees. 

Rachelle earned her master’s degree in Landscape Architecture from the Rhode Island School of Design, where she had a research emphasis on collaborative community design and youth development. She also holds a B.A. in History and Africana Studies from the University of New Mexico.

A favorite plant for Minnesota gardens is yet to be discovered, but Rachelle greatly looks forward to exploring the Midwest plant palette after many years in desert environments.

A self-professed plant guy, Tim has woven his passion for plants into his professional life. In addition to serving as the head of the Education team at the Arboretum, which reaches more than 30,000 participants every year — in person and online — Tim also serves as the state director of the Master Gardener Volunteer Program, which reaches over 140,000 Minnesotans through 3,000 volunteers and is part of the University of Minnesota Extension.

Tim has a broad background in the horticulture industry and extensive experience educating learners of all ages in diverse settings — public schools, urban neighborhood gardens and at the Minnesota Landscape Arboretum since 1993.

He enjoys leading a creative, dedicated staff of educators who create experiences for people of all ages, abilities and circumstances to connect with plants. Of special interest to Tim is exploring topics that are relevant to healthy people, plants and the planet, such as clean water, healthy food, urban agriculture, nature-based therapeutics, climate change, pollinators, biodiversity, sustainability and conservation.

Tim holds three degrees: a bachelor’s in Horticulture, a master’s in Education and a master’s in Public Affairs. In 2009, he received the University of Minnesota's College of Food, Agricultural and Natural Resource Sciences Distinguished Diversity and Inclusion Staff Award for his work.

In his free time, he enjoys gardening and photography. His favorite plant for Minnesota gardens is rose milkweed (Asclepias incarnata).

Susan leads five Arboretum teams organized under the Advancement department — Development, Gift Administration, Membership, Marketing & Communications and Database & Project Management — working to advance the mission of the Arboretum through the engagement of visitors, members, donors and even those who have yet to discover the Arboretum.

Since 2015, Susan has been involved in efforts to raise tens of millions of dollars for Arboretum annual operations, capital improvements, endowments, bequests and other fund-raising priorities, first as a Planned Giving Development Officer and later as Director of Development. Now presiding over Advancement, Susan leads efforts in branding, marketing and communications strategy; membership stewardship and retention; and gift-recording and gift-acknowledgement processes at the Arboretum. 

Susan has a Ph.D. in Educational Policy and Administration-Higher Education from the University of Minnesota-Twin Cities; a master’s degree in Rehabilitation Counseling from Minnesota State University-Mankato; and a bachelor’s degree in Natural Science from Christian Brothers University in Memphis, Tennessee. Susan previously served as Director of Development at Minnesota State University, Mankato, where she taught in the Nonprofit Leadership program.

An avid horticulture enthusiast and plant collector, Susan has a deep and sincere passion for the Arboretum as a public garden and as a research leader in woody plant breeding. Living with her husband and grandson in Shorewood, Susan tends an extensive garden of native plants, perennials and vegetables as well as University of Minnesota woody plant introductions. 

Her favorite plant of Minnesota gardens is liatris, commonly known as blazing star.