In Memoriam: David J. Muffly (1965–2025)

Many oak-lovers were saddened this fall to hear of the passing of Dave Muffly, a California Master Arborist and oak expert extraordinaire. Dave served as a key member of the committee to organize the 2018 International Oak Society Conference in Davis, California. Most notably, Dave led the unforgettable Post-Conference Tours, including a rare, behind-the-scenes opportunity to visit Apple Park, a corporate campus that he planted with thousands of trees and over 60 species of oaks. Dave also shared his work with the IOS in a session he led at the 2022 conference in Las Cruces, New Mexico.

A visionary futurist, Dave was an early advocate of shifting urban tree selection to prepare for the impacts of climate change. After studying the performance of countless urban trees in the San Francisco Bay Area, Dave determined that heat- and drought-tolerant oaks from southern California, southwestern US, Mexico, and the Mediterranean Region had strong potential to improve the climate resilience of California’s urban landscapes. The tree collection in Shields Oak Grove at the UC Davis Arboretum was a particular source of inspiration and acorns for Dave, and that is how I first met him.

Dave was laser-focused on his target. He wanted to find the best heat- and drought-tolerant trees with good vigor, strong and upright branch structure, pest- and disease-resistance (especially for powdery mildew), and no marcescence. He grew out hundreds of acorns from Shields Oak Grove, and after tirelessly selecting among his seedlings for his desired traits and roguing out hybrids, he determined that finding mother trees in wild oak populations would be more effective for commercial production. Through extensive testing and travels, he identified productive mother trees in California and Arizona for the species he found most promising for California landscapes—particularly Quercus engelmannii, Q. oblongifolia, and Q. hypoleucoides. 

Beyond selecting for the best seed genetics, Dave was also determined to make sure that quality trees were available in the California nursery industry. He partnered closely with Dave Teuschler, former Director of Horticulture at Valley Crest Tree Company and Chief Horticulturist at Devil Mountain Wholesale Nursery, to grow oak seedlings in air-pruning pots to produce vigorous, superior container trees free of root defects. Through these partnerships and influence, Dave Muffly played an instrumental role in expanding the palette of oaks available for urban plantings in California and increasing the demand for them among landscape architects and municipalities. Many thousands of trees have been planted across the state from the acorns he gathered.

Eager to share the lessons he learned from the Apple Park project and his other experimental oak plantings, Dave launched the Oaktopia website, where he shared detailed information on the performance of many oak species in California’s urban landscapes. This site expanded Dave’s influence beyond California to arborists and oak enthusiasts around the world.

I first met Dave 20 years ago, shortly before we attended the 2006 IOS Conference in Dallas together. He was always generous to me with his time and expertise. His perspectives on the urgent need to adapt urban forests for climate resilience were tremendously influential for me and helped shape my ideas on a major current focus of my work. I have found his detailed and astute observations on tree performance to be unparalleled—no wonder he has been called an “oak whisperer”. I’m so grateful for all that I learned from Dave and heartbroken that our oak-fueled friendship has come to an end. His legacy lives on with the many trees that he started, knowledge that he shared, and inspiration that he sparked in countless tree-lovers.

Further Reading

• A tribute page to Dave with opportunities to share photos and comments
• Dave’s Oaktopia website.
• Roderick Cameron’s blog post on the 2018 Post-Conference Tour in the San Francisco Bay Area.