I’ve got four marijuana plants growing underneath a 150-watt high pressure sodium lamp. They are only two weeks old and are doing well. My location in the UK is frequently cloudy, but, when it is sunny, I put my marijuana plants on the window sill so that they receive the full natural light spectrum. When the clouds start to head back, I place the marijuana plants back under the lamps. I recently read an article that suggested that transferring the plants between different light sources could wind up killing them because they haven’t adjusted. Is there any truth to this?
The marijuana plants could have an issue if they are put in the window only a couple of times per week. The might be used to a certain intensity of light and exposing them to a much higher intensity could cause them to suffer. If the sun coming through your window is incredibly bright, it might be too much for the marijuana plants to handle.
The leaves will get a sunburn, which will be a major detriment to the plants. If you routinely put the marijuana plants under the lamps and the sunlight on a daily basis, the plant will acclimate to and appreciate the extra intensity. The glass in the windows will filter out a large portion of the UV light, so the marijuana plants won’t start adapting to outdoor life.