“In your column you suggested continuous light during the vegetative cycle. I learned in biology that a plant needs a light and a dark period. The plant produces energy during the light cycle but uses it during the dark period. Lab experiments have shown that plants grow slower under continuous light.”
- Camden Town Jack, London, England
During the light period, plants photosynthesize, but they also continue all other phases of metabolism including respiration and growth. Observations of comparable gardens on 18-hour light cycles and continuous lighting show that marijuana plants do not need a dark period. The plants grow about a third faster on continuous light as compared with 18/6.
- Ed Rosenthal
The Best of Ask Ed: Your Marijuana Questions Answered