Vegetative growth is the second stage in the plants life following germination and before the onset of flowering typically about 6 weeks long. During the veg stage the plant is growing into sexual maturity and will be photosynthesising as much as possible to achieve maximum growth prior to budding.
During this time the plants need to have light a minimum of 18 hours per day. It is also a common practice to leave the light source on 24 hours per day during the veg cycle and accelerate growth. There have been no controlled recordings of increased hermaphroditism with the light on all the time. Most growers use the full 24/0 cycle.
18/6 or 24/0?
Those numbers refer to the amount of light and dark that the plant receives (18 hours of light / 6 hours of darkness). Anything above 14 hours of light per day will keep the plant in vegetative mode-- growing leaves and not buds. Flowering (bud development) starts occuring when you reduce the cycle to 12/12.
ADVANTAGES OF 18/6
- Reduced electricity costs. Lowering the cycle will save money especially if you use HID lights such as metal halide to veg.
- Allows the equipment and room to cool down. Some growers in hot climates time those 6 hours of darkness to happen during the hottest part of the day providing some temperature relief in the grow room.
