Ask Ed: Grow Questions and Answers – Dark Cycle Interruption

CANNABIS CULTURE – Ganja Guru Ed Rosenthal on the effect of light exposure during dark periods.

Q: Is it true that the plant cannot be exposed to any light at night because it affects the development of the bud? Is there any way of correcting this?

One night during the second week of flowering my buds were exposed to a very strong flashlight. I also have a greenhouse and suspect that the buds are exposed to light from headlights coming from the road, about 30 feet away. I’ve noticed that the buds start to tower, and the production of hair is reduced. Is it possible for these buds to fill in?

Do you think the effects are from the single flashlight exposure or from the headlights?

Imantia J., Internet


Ed: A single flashlight experience, even in the important formative stages of the second week, will have little effect on bud development. If the buds are growing thinner and longer than usual then the headlights are the culprits.

There is no way to repair the damage and lanky growth that already occurred, but you can prevent the light from affecting future growth almost immediately. Just start blocking the light from the plants. Perhaps you could hang an opaque curtain each evening inside the greenhouse. A bamboo fence lined on one side with opaque plastic might also work.