Lightning and flowering



Is it possible for lightning to postpone the flowering process in an outdoor cannabis crop?



Hi Cannagrow

Cannabis plants, much like chrysanthemums, react to light periods in similar ways because they are both short-day plants. They flower dependent upon the number of hours of total uninterrupted darkness they receive every night. For cannabis, this is generally around 9 to 12 hours per day.

Studies conducted on mum flowering for nurseries prior to the development of automatic controls showed that the controls that received 12 hours of uninterrupted darkness every night during the early summer produced normal flowers. A second group of flowers was given the same regimen for six nights, but the shading was left open on the seventh night, which produced a longer period of light. A third group of flowers had the curtains left open on two nights back-to-back. As you might expect, these two flowers were 6/7 and 5/7 (respectively) as large as the original controls. Ripening was also somewhat delayed.

When subjected to occasional interruptions in the light cycle, marijuana flowers tend to grow air, lanky buds and ripen slightly later than usual. Even so, the brightness of the lightning is not so intense that it reaches a threshold for flowering. Indeed, a bright full moon still doesn’t affect the plants. I have yet to see any papers or reports that indicate any effect that lightning has on flowering time, even in areas where the lightning strikes nearby during the flowering season.