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12 and 12 from seed cannabis

12-12 simply refers to the hours of light and darkness a cannabis plant is exposed to – 12 of each. Normally, a cannabis plant is exposed to an 18-6 light cycle. This tells the cannabis plant conditions are good for growth, and it focuses on building up size and foliage. When light cycle is changed to 12-12 (either naturally or through human intervention), it tells the cannabis the seasons are changing, and it is time to flower. By forcing a 12-12 light period from the start, the cannabis plant goes directly into flowering, in a bid to reproduce. You are essentially tricking the plant into thinking the growing season is coming to an end, so it needs to produce flowers ASAP.

Growing with a 12-12 photoperiod is a solution to space and resource problems. This method eliminates the vegetation phase of growth and forces the plant to go straight into flower from a seedling. Yields are lower than that of a regularly grown cannabis plant, but results are obtained much faster, with a few advantages.


Growing 12-12 is as simple as changing the timing on your light cycles, giving your plants equal amounts of day and night right from when they sprout. The plants will look different to a cannabis plant that goes through vegetative growth. Photosensitive hormones in cannabis make the highest point the largest cola. This method all but guarantees only main bud growth on every small plant. Essentially you will be growing a cola with a few short, budded side branches – with the plant basically being a bud in itself. Be sure to stake your plants.

Plants with less side branching and canopy spread need less space between them, increasing efficiency. As an example: 1x 15-litre pot produces one plant with a large volume and difficult maintenance issues in a cramped space. 4x 3.5-litre pots in the same sized space can produce just as much dried material with the benefit of being easier to rotate, so the whole plant gets 360-degree light. The entire crop is less hassle during maintenance as each plant is 100% accessible and physically easier to move about. There is no need for a separate sprouting and veg space or time wasted on 18-6 vegetation. The seeds can be sprouted under the 12-12 growing lights providing continual flowering plants.

Force flowering marijuana from seed can provide excellent quality, resinous flowers, all the while saving space, time, and money. For those with space constraints, it is a win-win!

When we germinate a Cannabis plant and plant it correctly, even though we begin to give it only twelve hours of light and twelve of absolute darkness, the plant will not flower. This happens because the plant needs to have certain sexual maturity before it will start to bloom (maturity is obtained between 3 and 6 weeks after it is germinated).

From the third week after they germinate, or a few days more … the plants will begin to show their sex and flourish (we will have saved at least a week in the growth phase).

Cannabis Light Cycles

As the plants do not grow as much as if we had given them a previous growth cycle of growth at 18/6 or 24/0, we will obtain plants that are somewhat smaller in size, so they can take better advantage of the lighting of our focus. Interestingly, they do not develop many branches with this technique, which will allow us to include more specimens in the same grow space.

When growing and flowering 12/12 We must keep some things in mind, such as avoiding pot transplants. It is advisable to put the germinated seed in its final pot, and that it is of an acceptable capacity. If we grow in soil we will try a minimum of 12 liters per pot, while if we grow in coconut with 7 liters per pot it will be enough.

Not all are advantages … there are those who affirm that less production is obtained or that the flavor/quality diminishes with respect to those that have been cultivated with a previous cycle of growth.