Professional Marijuana Grower September-October 2017 Issue | Page 22

Feature Article
Best Artificial
by Eric Hopper
LIGHT
SOURCE
for the Flowering Stage of Marijuana
T
he pinnacle of indoor marijuana production occurs in the flowering stage of growth.
After waiting weeks for the plants to reach the desired height, a grower will introduce
his or her plants to a 12 hour photoperiod, thus initiating the flowering stage. The
flowering stage is the final stage of growth and is when marijuana plants produce
the sticky, sought after buds. The flowering stage can last eight weeks or longer, which
means the lighting system used in this stage is quite possibly the most influential factor over
the way the buds develop. Multiple light technologies can be used successfully for flower-
ing cannabis. Growers who understand the basics of the different lighting technologies will
know when and where to use each and this knowledge will lead to a higher likelihood of
success.
Light Intensity
Before discussing each individual lighting technology, it
must first be noted that, regardless of the light technology
being used, the secret to success is correctly utilizing the
light energy. Light intensity, as it relates to indoor hor-
ticulture, is referring to the amount of energy available
to the plants. One of the biggest mistakes a grower can
make in the flowering stage is not providing the plants
with enough light intensity. A general rule of thumb is
to provide a minimum of 40 watts of light energy per
22 • Professional Marijuana Grower
square foot of garden space. After a marijuana plant
enters the flowering stage, it will continue to grow so it
is important to provide the light intensity that is adequate
for the plant’s finishing size.
In other words, in the beginning of the flowering stage,
the light energy may be somewhat disproportionate.
The total light energy needed will be determined by the
finishing size of the plant, not the size of the plant when
SEPTEMBER/OCTOBER 2017