Marijuana is a sun-loving plant and will easily grow to large heights if provided with enough solar contact. But since marijuana is also a durable and resilient plant, growers have been able to successfully obtain buds from marijuana plants grown with only a skylight.
Sunlight encourages leaf and stem production, which in turn enables the cannabis plant to retain more sunlight, ultimately leading to more growth, larger yield and better weed. If your cannabis plants don’t receive adequate sunlight, no amount of soil and water preparation will compensate for this crucial deficiency.
While light is necessary for growth, it is darkness that actually triggers flowering in mature marijuana plants. Once a mature plant receives a certain minimum amount of uninterrupted darkness for a week or so, this signals to the plant that the growing season has ended. The mature marijuana plant will begin to convert its energy from growing to flowering. This is why it is best to grow your marijuana plants as early in the spring as possible so that they receive the maximum amount of light, and can therefore spend most of their life cycle growing.
It is best to try and plant in a spot where your marijuana plants will receive sunlight for the longest possible period of time. Midway through the growing season, when the days are longest, the sun can be shining for 12 or more hours a day. Your goal is to find a location such as a clearing, free of trees or other obstacles that could prevent your plant’s leaves from capturing the sun’s rays and using them to power growth.
South-facing sites are usually the best in the northern hemisphere and vice versa for those in the southern hemisphere. This may not be possible for everyone due to other concerns like security or perhaps access to water. In that case make sure your cannabis plant receives at least five hours of direct sunlight and five hours of indirect sunlight each day. If you must choose between morning sun and afternoon sun then the consensus is that morning sun is best for growth.
Some northern marijuana growers experience a different problem: darkness plays a large factor in northern regions. Since the nights are short, the marijuana plants may not have enough time to flower before autumn sets in and, with it, the first frost. For these growers, being able to simulate a longer night to trigger flowering may be necessary. In this case a greenhouse or other enclosure may be the only way to grow outside. Please note that the darkness must be total as any light the marijuana plants receive, even if only briefly, will stall flowering and restart vegetative growth. LED lights are a good option to use in greenhouses or other enclosures. You can find some below:
Cannabis growers near the equator or in other southerly places with long periods of darkness (more than ten hours for consecutive nights) may find that their cannabis plants flower too soon. This is a lot easier to deal with since shining light is always easier than withholding.
Either way, it is important to remember that light, because it is important to both the vegetative growth and flowering stages, should be looked at from the perspective of the plant’s entire life cycle. One of the great advantages to growing outdoors is that, providing that you have picked a great spot for the cannabis plants, the sun and changing seasons should do the rest.
Besides light, water, temperature and fertilizers the genetics of the marijuana seeds are very important. Bad genetics can never produce high quality marijuana.