Bert Cregg

Bert Cregg

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Department of Horticulture



PhD in Forest Resources, University of Georgia, 1990
MPA in Public Administration, University of Nebraska, 1995
M.S. in Forest Science, Oklahoma State University, 1986
B.S. in Forest Management, Washington State University, 1983
A.S. in Forestry, Centralia College, 1980

Area of expertise: physiology and management of trees in landscapes and nursery production

Research Interests

Dr. Bert Cregg conducts research and extension programs on tree physiology and management of nursery, landscape, and Christmas tree systems.

Key research and extension program areas include:

  • Slope restoration on urban freeways
  • Culture and genetics of Christmas tree production
  • Water and nutrient management of shade trees and conifers in Pot-in-Pot production
  • Promotion of increased tree species diversity in urban and community forests

Current Research Projects

Landscape plant selection and management for slope restoration on urban freeways

Background and objectives: In this project we are investigating strategies to improve establishment of landscape plants on urban freeway roadsides. In the summer and fall of 2018, we established a series of replicated plots along I-696 north of Detroit in collaboration with the Michigan Department of Transportation (MDOT) to evaluate landscape plants (shrubs, herbaceous perennials, and grasses) and site preparation practices for slope restoration along urban freeways. Results from this research will inform decisions on site preparation practices and plant selection for similar sites in Michigan and the Midwest. Expanding the range of plant selections for roadside plantings beyond turfgrasses will provide new markets and opportunities for Michigan nurseries.


  • Robert Schutzki
  • Maddy Dubelko (graduate student)


  • Michigan Department of Transportation
  • MSU Project GREEEN
  • Michigan Department of Agriculture and Rural Development Horticulture Fund Greening of Detroit

Culture and genetics of Christmas tree production

Research and extension efforts at MSU are addressing several key and emerging issues for Michigan Christmas tree producers.  Current research projects include;   

  • Understanding environmental control of coning in Fraser fir
  • Use of plant growth regulators to control coning and shoot growth of conifers
  • Establishment of a Fraser fir seed orchard at the Horticulture Teaching and Research Center
  • Establishment of large-scale test plantations of Turkish and Trojan fir as part of the Collaborative Fir Germplasm Evaluation (CoFirGE) project; a multi-institution program with North Carolina State University, Oregon State University, Washington State University, and Pennsylvania State. 


  • MSU Project GREEEN
  • Christmas Tree Promotion Board Research Fund
  • Michigan Christmas Tree Association

Improving transplant success of container-grown landscape trees

In this project we are examining long-term responses of trees to nursery culture, planting and maintenance in order to better understand the role of each step in tree survival and growth. We are comparing innovative practices, such as root-shaving or bare-rooting container-grown trees at planting and application of plant growth regulators in the nursery, on long-term performance of trees in landscapes. The results of this research will provide nursery managers, landscape contractors, and urban foresters with additional tools to improve the long-term success of landscape and street tree plantings.

Goals / Objectives

  • Evaluate the impact of nursery cultural techniques on physiology and morphology of nursery stock and subsequent transplant success
  • Evaluate the impact of transplant techniques on transplant success of container grown trees
  • Determine the impact of mulching after planting on long-term success of container-grown landscape trees


  • Riley Rouse (Research Technician)
  • Michigan State University Project GREEEN
  • J. Frank Schmidt Family Charitable Foundation
  • ICL Specialty fertilzers
  • Rainbow Scientific
  • J. Frank Schmidt and Sons Nursery
  • Renewed Earth, Inc.
  • Nursery Supplies, Inc.

Physiology of nursery crops irrigated with recycled run-off

Co PI’s: Tom Fernandez (MSU lead), Bridget Behe

Graduate Student: Shital Poudyal

  • Access to high quality water for nursery irrigation is increasingly limited. Growers need to develop alternative sources of water (e.g. recycled water). Stakeholder reluctance to use recycled water is motivated by the presence of pathogens and agrichemical contaminants, and the lack of readily available information about treatment technologies in terms of economic viability and efficacy.
  • As part of a Multi-institution USDA SCRI project (Clean WateR3 - Reduce, Remediate, Recycle) we are investigating the potential impacts of irrigating nursery crops with remediated and recycled run-off water.  Understanding the impacts of recycled water on crop health and function is critical to grower acceptance of these emerging technologies.


  • MSU Project GREEEN
  • Michigan Department of Agriculture and Rural Development
  • Michigan Nursery and Landscape Association
  • Renewed Earth, Inc.
  • Nursery Supplies, Inc.

Selected Publications

Selected Extension Publications