A recording of this extremely popular and useful lecture is available for purchase and viewing through October 23, 2025.

Pacific Northwest gardens often boast an enviable range of conifers and hardwoods, but successfully planting underneath them can be challenging due their substantial root systems, heavy water demands and expanding shade. In addition, misunderstandings about mature trees’ roots can lead to the eventual death of these prized older trees, while repeated efforts to cultivate grass and other plantings beneath them can become frustrating and costly. Drawing from decades of expertise, Christina will share valuable lessons in how to successfully anticipate and avoid these complications. She will also cover some cost-effective techniques to improve the long-term success for all plants in these landscape situations.

Speaker’s Bio: 

Christina Pfeiffer is a Seattle-based horticulture educator and ISA Certified Arborist who has enjoyed a long and interesting career in landscape horticulture. She holds degrees in horticulture from Michigan State and the University of Washington and brings practical experience and attention to current research to her presentations. Christina has met the challenges, successes and failures of gardening under mature trees through her past role as a horticulturist at the Washington Park Arboretum, as a consulting arborist and, for over thirty years, in her own garden.