Bert Cregg

Bert Cregg
Telephone: 517-353-0335

Department of Horticulture

Joint appointment with the Department of Forestry

1066 Bogue St, Rm. A214,
East Lansing MI 48824

Nursery Production

Area of Expertise:

Physiology and management of trees in landscapes and nursery production

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


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

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:

  • Urban tree selection in a changing climate
  • 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
  • Ornamental conifers

Current Research Projects

Urban tree selection in a changing climate

  • Background and objectives: Trees in urban and community forests are subject to a myriad of stresses that limit their survival and ability to contribute ecosystem services. Climate change will compound these stresses, especially temperature stresses associated with urban heat island effects. Urban and community landscapes in Michigan are especially at risk due to heavy losses of ash trees associated with the emerald ash borer outbreak. 
  • In this project we will identify street tree cultivars that show a high potential to adapt to potential climate change and urban stresses. The project is being carried out in two phases. In Phase 1 we are conducting intensive greenhouse trials to determine the relative ability of street tree cultivars to acclimate their physiological responses to changing temperature regimes. In Phase 2 we are working with a community forestry partner (Greening of Detroit) to compare the ability of cultivars to acclimate under contrasting urban conditions.
    • Support:
    • MSU Project GREEEN
    • J. Frank Schmidt and Sons Nursery
    • J. Frank Schmidt Family Charitable Foundation
    • The Greening of Detroit
    • Renewed Earth, Inc.
    • Nursery Supplies, Inc.

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.  On-going focus areas include understanding environmental control of coning in Fraser fir, developing strategies to reduce coning, improving nutrient management, and pest management.  In addition, several projects on genetic improvement of Christmas trees for Michigan have recently been initiated. These include: 
    • Establishment of a Fraser fir seed orchard at the Horticulture Teaching and Research Center
    • Initiation of efforts to develop interspecific fir hybrids
    • 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. 
  • Development and use of genomic tools to improve firs for use as Christmas trees (USDA SCRI grant with NCSU and others)
  • Support:
    • MSU Project GREEEN
    • 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 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
  • Support:
    • 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.
  • Support:
    • MSU Project GREEEN
    • Michigan Department of Agriculture and Rural Development
    • Michigan Nursery and Landscape Association
    • Renewed Earth, Inc.
    • Nursery Supplies, Inc.
    • Peterson’s Riverview Nursery

Selected Publications

Selected Extension Publications


Tags: msu extension, nwmhrc researcher

Authored Articles