What is 12/12 when growing Cannabis?

12/12 is shorthand for “twelve hours of light and twelve hours of darkness”. This means to have your grow lights turned on for 12 straight hours, then off for the next 12 hours.

Why use 12/12 when growing Cannabis?

The 12/12 light schedule lets cannabis plants know that it is now time to make buds/flowers instead of growing leaves and stems. It’s important that cannabis plants get no light during their “dark period”.

Changing your light cycle to 12/12 or 12 hours on – 12 hours off is what triggers your plants to start and maintain the flowering stage of growth. This is the plants natural way of understanding and changing with the season as their life will be coming to an an end and it is time to reproduce. The female buds are what is desired from cannabis and those buds cannot be produced outside of the 12/12 light cycle unless the plants are of rederalis or autoflowering lineage.