Greenhouse and Horticultural Lighting

Date: September 10, 2015 - March 31, 2016
Location: Online
Contact: Heidi Wollaeger,, 269-384-8010

Michigan State University Extension is now offering a non-credit pre-recorded online course on greenhouse and horticultural lighting. It is the second course in the College of Knowledge Online series offered on the eXtension campus, the national Extension website. The course is intended for greenhouse and ornamental plant growers and others interested in learning about the fundamental concepts about how plants respond to light quality, quantity, and in duration. It provides introductory to moderately-challenging content based on experiments performed at Michigan State and Purdue Universities.

The 3-hours of pre-recorded lecture and video demonstrations are divided into seven units:

  • Unit 1: What is Light?
  • Unit 2: Importance of Light for Plant Growth   
  • Unit 3: Light Quality
  • Unit 4: Light Intensity         
  • Unit 5: Light Quantity 
  • Unit 6: Photoperiod and Photoperiodic Lighting
  • Unit 7: Low- and High-Intensity Lighting

The first and second units cover the properties of light and its importance for plant growth and development. The third unit discusses how light quality influences stem extension and flowering. The fourth unit of the course teaches students about light intensity and its importance for plant growth. It also covers the factors that affect light availability and how to manipulate and measure light intensity in the greenhouse. Unit four also features four videos that demonstrate how light transmission is affected by the glazing material of a greenhouse, how growers can measure instantaneous light intensity and daily light integral in their greenhouse, and also how to measure light intensity and quality from light-emitting diodes (LEDs). The fifth unit discusses how light quantity affects plant shoot and root growth and branching, focusing on responses to the average daily light integral (DLI). Unit six covers photoperiod and photoperiodic long-day lighting strategies, featuring the latest research on delivering long days with LEDs. The final unit on supplemental lighting discusses the advantages and limitations of different lamp types, provides guidelines of when to deliver supplemental lighting to increase DLI, and the factors to consider when selecting a lamp for your horticultural application.

The course is instructed by Heidi Wollaeger, Greenhouse and Nursery Extension Educator, with Michigan State University Extension. The course was adapted and updated from the original College of Knowledge unit developed by Dr. Royal Heins (Professor Emeritus, MSU) and includes a substantial amount of recent research by Dr. Erik Runkle (Professor of Horticulture, MSU).  Supplemental content including videos demonstrating concepts are from Dr. Roberto Lopez and Garrett Owen (Purdue University).

Students enrolled in this self-paced course will take a pre-test and a final exam to gauge their progress on the topics of the course. Self-assessment quizzes will engage students with the material throughout the course. The course also provides links to 36 trade articles published on pertinent lighting topics. 

Greenhouse and Horticultural Lighting is available through

Cost: $129 per student
Once purchased, the student will have access to the course for 6 months from the purchase date.

Cancellation policy:
 Due to the online nature of this course, students wishing to cancel their registration are subject to a $129 fee. 


Events Nearby

View more events