However, when growing weed indoors, a marijuana gardener will have to fool their plants into "thinking" winter is coming to induce flowering and kickstart the creation of buds.
Photoperiod dependent strains vs. auto-flowering strains
So unless you're planning on breeding, it's important that most growers destroy male plants as soon as you notice them growing grape-like balls where their buds would normally be.
So all strains of cannabis that respond to light in this way (where the light period effects what stage they're in) are called "Photoperiod dependent" strains.
Unfortunately, about 50% of all regular (unfeminized) cannabis seeds are male (though this varies from strain to strain, and from environment to environment). Fortunately for small growers, you can purchase feminized (all-female) seeds so you don't have to worry about male plants if you don't want to. Learn more about buying seeds.
I tend to set my timer to shine line from 8pm-8am. This gives me time to check on my plants at night when the lights first come on, and I can also check them quickly in the morning before I go to work. It also keeps things cooler since the lights go on at night.
If you're growing a cannabis plant grown from a random seed ("bagseed"), unless you somehow have an auto-flowering seed, you will need to understand about cannabis life stages and how they are affected by light periods.
But ANY 12 hour period will work, as long as you remain consistent.
By breaking the light cycle into multiple six-hour periods, the plant can rest and process the light it has received. When the lights come back on two hours later, the plant will be ready to process additional light, allowing you to get the most plant growth out of every minute your lights are on.
By turning off the lights for two hours at a time throughout the day, your cooling system will get a break between light cycles.
By turning off the lights for two hours at a time throughout the day, your cooling system will get a break between light cycles, allowing the room to be cooled to desired temperatures before the lights come back on. With a properly sized cooling system, this benefit will be minimized as the system will be designed to handle the heat load throughout the entire light cycle.
Benefits of a 6/2 Light Schedule
Many growers advocate the use of an 18/6 light schedule (18 hours on, six hours off) while plants are in veg. However, this may not be the most beneficial light schedule. Switching to a series of 6/2 light pattern (six hours on, two hours off) may increase plant growth while also potentially creating a more stable controlled environment.
Cannabis is a short-day plant, meaning it will only flower when exposed to long periods of darkness and short periods of light. For cannabis to flower, there must be at least 12 hours of continuous darkness. This allows for the use of a series of shorter light schedules while the plant is in veg—as long as the plant receives less than 12 hours of continuous darkness, it will stay in veg.
Giving plants six hours of intense light at a time not only puts less stress on the plants, it also spreads out the load on your cooling system over a longer period. The cooling system works the hardest when lights are on.
Cannabis is a short-day plant, meaning it will only flower when exposed to long periods of darkness and short periods of light.