Contributed by: Smokey D Dope
Thanks to: diels alder
Note: diels alder was instrumental in helping turn this very
technical subject into something much easier to understand. This is by
no means a complete, technical explanation of Botany, rather it’s an
understanding of the basic principles.
Many times I’ve seen in posts that “roots grow during the dark.”.
If this were true, the 24/0 photoperiod would result in a plant with a
tiny root structure, if one at all! We know this is not the case - so
how does it actually work?
To simplify things, lets use an analogy. Try to think of a plant as
a building… one constantly under construction. The plant needs raw
materials, (fertilizers and water), and energy (light) in order to
“build itself”. The raw materials are the “bricks and mortar” of the
building. The energy is the workers, vehicles and power tools used to
assemble the building.
The Plant is capable of storing some raw materials and some energy
for use later, but the amount is limited...think of a warehouse and a
During the day, (Lights ON) the plant is collecting and storing
light energy, and is using and storing raw materials. The plant is
stockpiling raw material, and is charging it’s batteries… it is ALSO
using raw materials and using the energy it is collecting. It’s
building itself, literally putting itself together.
During the day however, the plant is not as efficient at building
itself, as it is at night (lights OFF.) It can build itself, but not as
While the lights are OFF, the plant is using energy and
raw materials to build itself…. the plant is more efficiently using the
raw materials that it stored during the day. The plant is better at
transporting and assembling the raw materials.
The bad news: since there is no light energy, the plant must rely
on energy it stored while the lights were ON (its stored energy).
(Essentially, the plant is running on batteries, and using raw material
from the warehouse.)
There is no light energy to collect. Since the plant needs energy
to absorb more raw materials, it is easier for the plant to use raw
materials that it stored during the day than it is to absorb raw
materials through its roots.
Although the plant IS capable of “doing it all” with the
lights on, (Collect, store and use energy & raw materials) it does
a better job of actually doing the work (using the energy and raw
material) while the lights are out. During the dark however, it relies
solely on its limited supply of stored energy and stored raw material.
One last thing to remember is the fact that a plant will always
strive to maintain a balance between the size of its roots and the size
of its canopy (Leaf mass.) The roots must be big enough to supply as
much raw materials as the canopy can use, and the canopy must be big
enough to provide the energy required to store those raw materials….
Trim the roots on a healthy plant, and canopy growth will
slow to a crawl until the roots have grown big enough to again support
Trim the TOP of a healthy plant, and root growth will slow
similarly, until the canopy has grown big enough to again support the
If the plant is already in balance, the canopy and the roots will grow at the same rate.
If you actually measured them several times daily over several
days, you’d notice that they actually DO get bigger at night, but roots
and canopy at the same rate, unless either has been trimmed, and as
long as the “batteries” hold out.