Just like any horticulturalist, Medical Marijuana growers are constantly trying to maximize yields. Unlike most other horticultural fields however, Medical Marijuana producers are limited by the number of plants they are allowed to grow. Because of this limitation most medical growers are growing the biggest indoor plants possible to produce the largest amount of high quality medicine possible from smaller numbers of plants.
When it comes to growing Marijuana indoors, we have the benefit of controlling all the variables essential for plant growth. This includes the ability to extend or reduce day length, perpetuating summer or bringing on fall in the eyes of the plants to induce flowering. Most Marijuana strains will not flower when kept under 18 hours of light and 6 hours of darkness every 24 hours. Keeping the plants in this vegetative state allows them to grow as large as we like and using large pots allows the root system to grow as large as we like. When we want the plants to stop vertical growth and begin to flower, their day/night cycle is switched to 12 hours light and 12 hours dark every 24 hours. This combined with a low nitrogen, high phosphorus fertilizer will induce flowering and slow vegetative growth.
In order for these large plants to produce to their maximum they need sufficient lighting. For some growers this may mean one 1000w High Pressure Sodium light hung vertically per plant, and/or bulbs without shades being dropped between plants to ensure sufficient light penetration of the canopy. This method of growing “Monster Plants” can have excellent results. Growers report yields as high as 2lbs per 1000w but it also has its disadvantages.
A sea of green style grow is a favourite of large scale, commercial growers. They use many small plants (sometimes as many as 50-100 per light!) to create an even canopy which can be lit using lights hung horizontally, allowing for more efficient lighting of the crop. With monster plants, often reaching more than 6 feet in height and four feet in diameter, the additional bulbs needed to ensure proper light penetration can lead to heat problems and or course higher power costs. Fortunately there is a simple solution to this problem. We've already learned how to control every aspect of the plants environment to create monster plants, the next step is to control the plant itself by using a technique called training.