2021 7th Annual Tree Diversity Conference - ONLINE

To protect our urban forests, which are threatened by pests, pathogens, and climate change, a greater variety of tree species is necessary.

This session will be streamed live online. Details on how to join the class will be emailed the day before the program. Participants will have access to the symposium recording for 14 days following the live class.


For our seventh annual conference we will continue to explore the relationships between landscape design, horticultural practices and the use of a greater variety of tree species.


Between them, our speakers this year boast an extravagant depth of experience ranging from worldwide plant exploration to landscape and garden design, promotion of new plant materials, administration of some of our country's most noted horticultural conferences and institutions and hands-on experience with plant testing and data collection.



Price: $45 Public, $40 Promo , $20 Student

*Promotional price available to all Members of Colorado Tree Coalition and American Society of Landscape Architects


Speaker Lineup

Steve Foltz presents A Virtual Tour of My Favorite Outstanding Trees of the Cincinnati Region

I'm sure many of you have not yet had the pleasure of touring the best trees in the Cincinnati region. If you were to visit Cincinnati, what would such a tree tour look like? Where would you go? Which arboreta, botanical gardens and nurseries would be on your list to see the best specimen trees in our region? Find out through this lecture. For more than 30 years, Steve Foltz has had the pleasure of searching out the best trees in the landscapes of Cincinnati and will now share them with you.

Foltz is the director of horticulture at the Cincinnati Zoo and Botanical Garden. He has a B.S. in horticulture from the University of Kentucky. Steve also has been teaching woody landscape plant courses at both the University of Cincinnati and the Cincinnati State Horticultural program for the past 25 years.


Keith Warren presents New Deciduous Tree Cultivars and Suggestions for Denver

What's new? What's best? And where are we in the development of deciduous tree cultivars? Keith Warren, co-author of The Tree Book, Superior Selections for Landscapes, Streetscapes and Gardens, shares the current status of the best choices among the deciduous tree species and cultivars. He discusses the most recent introductions, breeding trends and future directions and offers suggestions for Denver's difficult climate.

Warren spent a 40-year career with Frank Schmidt & Son, Co. as a nursery manager, researcher and director of product development. Recently retired, he is still active with the company and continues to introduce new tree cultivars.


Peter Zale presents The Role of Plant Exploration in 200 years of Tree Stewardship at Longwood Gardens

When Longwood become a public garden in the late 1950s, a plant exploration program was developed to fulfill diverse garden needs, one of which was to collect and evaluate an ever-expanding palette of hardy trees and shrubs suitable for the climate of the Brandywine Valley and beyond. Since the inception of the program, a staggering number of woody plants has been trialed and planted in the garden, and these efforts continue today. This presentation tells the story of plant exploration from the 1800s to the present with a focus on recent advancements of the program, anecdotes from the field and a discussion of the wide variety of new, useful and exciting trees and woody plants currently under evaluation and development.

Zale, Ph.D. is a plant collections curator, research horticulturist, field botanist and gardener who specializes in plant collections development, domestic and international plant exploration, ornamental plant breeding and conservation horticulture.


Sonia John and Neal Bamesberger present Reprising Some of Colorado's Notable Trees

Since the discontinuation a few years ago of the Colorado Tree Coalition's annual wall calendar, Sonia John and Neal Bamesberger have grown nostalgic for the photos and descriptions of 12 different champion and notable trees it used to feature each year. To compensate, they present photos and stories about their own personal notable tree selections, Sonia's from within Denver and Neal's from the further reaches of the state, some garnered during a recent champion re-measuring foray.

John has been chairwoman of the organizing committee for the annual tree diversity conferences since their inception in 2014. She was the senior author of "Denver's Canopy: The Nature of Deciduous Trees," published by Denver Botanic Gardens.

Bamesberger has a B.S. in horticulture from the University of Nebraska and is a certified arborist.


Panayoti Kelaidis and Alan Rollinger present Rollinger Tree Project

Panayoti and Alan discuss the findings of the Rollinger Tree Collection 50-Year Survey. The survey is a project conducted from 2017 to 2019 by Denver Metro city foresters, Master Gardeners, Denver Botanic Gardens staff and other volunteers, who tracked down the trees first located and measured by Alan Rollinger in the late 1960s. After these trees were identified and measured, a document with the results was published in late 2019.

Kelaidis is senior curator and director of outreach at Denver Botanic Gardens where he has worked for 40 years.

Rollinger has been a leading landscape designer in the Denver Metropolitan Area for more than 50 years, designing hundreds of residential and commercial properties.


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