hardhat22
New Member
I have read all of the posting rules I could find and I don't believe I'm breaking any rules by posting this article that I saved from a now defunct site.This is what I 'learnt on'.I haven't read a 'more better' article on scrog anywhere else.
Fundamentals of scrog growing under small lights
Posted by SCW on August 09, 1999 at 14
36 PT:
This article is intended to provide information for new growers using the
``ScrOG’’ or ``Screen of Green’’ method in mini or micro cabinets under
small HPS lights, in the range of 70 to 250 watts. I won’t discuss the
application at 400, 600 and 1000 watts, as that’s outside the scope of my
experience. Refer to Iguana’s site and others for information on what is
called production scrog.
Small HPS lights
Small HPS lights are perfect for growing cannabis in restricted space
conditions, as they produce the most light from a given amount of electricity
of any suitable lamp for cultivation, and produce a spectrum that is
favorable for flower growth. The spectrum is not the best for vegetative
growth, but that isn’t really important to scrog growing, as the vegetative
period is so short. Lights as small as 35 watts are available by stripping
components from security lights commonly available at discount hardware
stores. 250 watt lights can produce as much per foot in scrog conditions as
1000 watt lights in room growing. A single 70 watt light can produce enough
for an average pot smoker in a space as small as 1 sq. ft. MH lights are
available in small sizes, but they produce less light and more heat than
their HPS counterparts, and heat is an important consideration in
cabinet-style growing. Regarding fluorescents, the light to heat ratio is
even worse, and I am not aware of any situation in micro and mini growing
where I would favor them over small HPS lights.
Note that these lights are quite weak compared to 400, 600 or 1000 watt
lights used in production growing. I read a post recently on ADPC where the
question was raised whether two smaller HPS lights were equal to one HPS
light with the same total wattage. The answer is no, and the reason is
intensity. Consider a stream of water coming from a bunch of garden hoses
at normal pressure. You could stand in front of them, right? You’d be wet,
but they wouldn’t knock you down. Now how about the same volume blasting
you in the gut from the nozzle of a fire hose? You’re on your butt. Replace
the fire hose in the example with a 1000 watt light and a group of 70 watt
lights for the bundle of garden hoses, and you get the picture. Intensity
means that the light can be father away from the plant and still be bright
enough at the bud surface to produce. Intensity is necessary for tight bud
formation.
To get the most out of a small HPS light, you must keep the bud sites within
the productive range of the bulb, a lopsided sphere extending out from the
lamp source. For a 250 watt light, that circle of light extends out about
20-24" from the lamp. For a 70 watt light, the maximum distance is
apparently around 8" (per chthonic, who has experience with the lights).
A group of tall, skinny plants under such a light would only be properly
lit at the very tops of the plants, leaving the bottom parts shaded out and
in a low intensity light field, producing small, lightweight buds at best.
Ideally you would like all the buds within that magic circle of light
intensity, and you would like that sphere of light completely filled with
buds. How can that be accomplished?
The scrog method
The essential detail of the scrog method is a screen, usually poultry
netting, typically suspended between the planting medium and the lamp. The
plants grow up to the screen and then are ``trained’’ under the screen,
resulting in a flat table of plant growth, a field rather than a forest.
Because all the buds are growing at the same height, it is possible to get
all the growth within the effective circle of light from the lamp,
maximizing production from the space. It’s really that simple.
Well, nothing new under the sun, the method has been used for years. In
modern terms, the method was first popularized on the internet by the work
of pH on the usenet group Alt Drugs Pot Cultivation, or ``ADPC’’ for short.
You can access ADPC from several web-based sources, and pH still posts there
regularly. But the method as initially used by pH was designed to tweak
production from a large area under fluorescent lights, like the
``multi-shelf’’ method explained in his article on N.P. Kaye’s Lycaeum site.
N.P. Kaye is in fact credited with the term ``screen of green’’, which pH
shortened to ``ScrOG’’.
I am aware of a least one grower who used scrog and HID lights before that
time, based on a mention in Robert Clarke’s book ``Marijuana Botany’’, which
was also a source for pH. But most work involving scrog and HID lights is
quite recent. It is noted by pH that the first ``yield-o-rama’’ post
involving scrog with HID lights was in July of 1997.
Before discussing the method in detail, let’s explore the other alternative
for small HPS lights, the sea of green method.
Sea of green
The sea of green method was developed to maximize the speed of cannabis
growing in limited height situations. In a typical sea of green setup,
clones are planted at densities as high as 9 per sq. ft. Within a short time
after being established, the lights are switched to a 12 hour dark period.
What happens to the planted clone?
The clone could just sit there, stretch a bit under the light regime, and
flower, producing a tiny little bud with a couple of seeds. But that never
happens. Instead the clone takes off in a rush of growth, forming a woody
main stem and branches. If the plant is suitable for sea of green growing,
it will stop short of the lights and flower. Most indica dominated plants
stop short enough to be grown using this method. That process is at the
heart of the sea of green method, as it results in the smallest possible
plant flowering in the quickest possible time.
Why does the clone act in this manner? The actual process is subject to
debate. Your author suspects that the clone reads the light switch as fall,
and has a mechanism that recognizes that it’s too small to produce seed. So
the clone goes into a furious growth mode that stops when the plant reaches
a minimum height set within its genetic software, and then flowers. Others
argue that the clone’s response is just a variation on the normal stretching
process that happens when flowering is forced in any size plant. For
purposes of the discussion here, it doesn’t really matter why the response
occurs, just that you can rely on it.
The problem with the sea of green method under small HPS lamps is that it
produces a number of small spikes under the lamp, a forest rather than a
field. The plants crowd each other out and shade the lower portions, which
in any event are too far from the light source. As we discussed above, tall
and skinny is not productive under a small light. I grew initially using
this method, based on books and magazines that I read before designing my
250 watt system, and it worked well for many years, yielding just over
1 oz. per ft. Not bad, but it can be so much better.
Basic flat, fast scrog
The screen method used by pH relied on a long vegetative period for the
plants to cover a large area of screen held close to a series of fluorescent
tubes. The method I will describe here uses the same sort of growth process
that occurs in a sea of green plant, and is very fast.
The screen should be set about 8-12" above the planting medium. There are
two purposes for that gap. First, you have to get your hands underneath the
screen in order to handle the plant shoots and to remove excess growth
shaded out under the screen. Second, there needs to be sufficient space for
the plant to branch. Branching is essential to scrog. I prefer a space of
about 10" for a 250 watt light, but some growers prefer shorter gaps for
smaller lights, as little as 4-6".
Note that the screen does not have to be absolutely flat, and there are
good arguments for dishing the screen to match the curvature of the light
field. I don’t radically dish my screen, but I do tie down the middle of
the screen to prevent the screen from being pushed up, which would be
counter productive.
The clones are set under the screen at a density of about 1 plant per sq.
ft. Experience in using the method with various types of plants may result
in more or fewer plants, but 1 per ft. is a good starting point. Note that
plant density is much lower than for sea of green. That means less clones
to manage and fewer plants to be holding in a bust, a factor in sentencing
guidelines.
Why clones, by the way? By the time you find out which plants are male and
female from seed, it would be impossible to extract the males from the
foliage wound into the screen and fill in the gaps with female shoots,
without a real mess on your hands. Using seed plants requires modular
methods that are more suited to larger spaces and lights, and is outside
the scope of this discussion.
The clones are established and kicked into vegetative growth. Just about the
time where the growing tips penetrate a few inches above the screen, say at
three weeks, the lights are switched to a 12 hour dark period. Ideally a
response similar to the sea of green method kicks in as explained above.
Instead of stopping and flowering, the plants take off, filling the screen
with growth. At a density of 1 plant per ft., it usually works out that the
plants stop and ``crown off’’ just as the screen is filled. It’s really
magic to see it happen.
The timing is so critical. You must be around during this period to guide
the growth under the screen, and to make sure all gaps in the screen are
filled, one bud site per screen hole with standard poultry netting. Excess
leaf growth must be removed above the screen, which usually means all the
fan leaves are removed. Never mind arguments about whether fan leaves should
or should not be left on plants, this is a different animal, and the rule
here is, all bud sites must see the lamp to develop. At least in a small
scrog grow, fan leaves would overwhelm the neighboring buds. Get a good
sharp, clean set of pruning scissors and just leave them with the grow.
You’ll need them every couple of days during this period.
Training really isn’t difficult. With a limber plant I usually let the
shoots grow vertically above the screen and then pull them under by the
stem, re-orienting the stem horizontally under the screen to line up bud
sites with screen holes. You don’t have to tie anything down, as the upward
pressure of the stem will nail the foliage to the screen, but some growers
like to tie off stems to the screen during the early phases of screen
filling. Here’s what one grower, Ultimate, has to say on the subject:
``I swear by twist ties and have a huge stock. They can be found just about
anywhere. Purchase ties which are most flexible (wire with the smallest
diameter) and coated with plastic not paper, as the paper will eventually
mold.
``So why twist tie? Two reasons when training for in any screen application.
1. Pre-training. (Exact placement of main stems, growth shoots and branches)
2. Bud-training.(Bending, stem crushing/crimping, and repositioning)
``When initially induced to 12/12, the main tip/tips that hit the netting
are immediately trained 90 degrees perpendicular to the netting. This allows
for the light to concentrate the most productive part of the plant, forcing
the most efficient production the plant can dish out. Branches under the
netting are allowed some time to reach the light, but less than half will
see light because you're concentrating on efficiency. The most efficient
growth will occur where the main stem bends on a 90 degree and beyond,
which receives the most light.
``I like to leave the ties long enough for the plant to hold the shape
desired.
Main stem usually around the second week (give or take) , and branches will
always vary. Branches coming off the main stem parallel to the netting are
spread as far from the main stem as possible making for a even canopy, more
bud sites per square, and controlling overall height.
``To a certain extent the buds freeze at a certain point and height/stem
length slows. The canopy height is close to being established, but some
plants are more vigorous than others and continue to stretch beyond the rest
of the crop. When bud training the longer colas are controlled by bending
and tying down to the screen with twist ties. In extreme cases
crushing/crimping is necessary. Moldy buds can be avoided by repositioning
buds growing against each other. By using twist ties each bud can be
positioned where air flows between each cola allowing efficient light
dispersal within the canopy and better air flow.
``Without ties? Yield was lower. A few larger colas had to be tied down
shielding smaller buds from direct light, not to mention forcing the light
to be raised higher, lowering production (This can be resolved by switching
to a more intense bulb) . Some branches grew buds with LONG stems between
the screen and base of the cola to compete with the large colas. Hybrid
vigor in some cases, or plants which tend to "stretch" more than others
eventually straighten out the 90 degree angle exposing less area of the
most efficient portion on the plant and eventually stretches to a point
where more stem was exposed to direct light, above the screen than desired.
A view from the bottom (planter to the screen) showed that efficiency could
be improved.’’
Some plants have brittle stems, and are difficult to train. It is possible
to bend a stem by crushing it lightly at the bend. So long as the structures
in the plant that carry fluids aren’t damaged too much, the shoot will heal
and be just fine (thanks to Uncle Ben for that trick). It may also be
possible to top brittle plants under the screen, so that the future growth
will be in several, more slender shoots. I have no experience in training a
scrog grow by topping.
The second pruning step occurs during and after the screen is filled. All
growth under the screen must now be clipped off. Shaded growth quickly
shrivels and dies, leaving ideal growth mediums for mold. Excess leaves and
shoots should be clipped close to the stem, to avoid leaving stumps as mold
sites. Robert Clarke recommends pruning away from the stem, but a lot of the
standard advice has to be discarded when dealing with the special
conditions of a scrog grow. The space under the screen is dark and humid,
and you want as little plant material under there as possible. You will
haul out buckets of leaves and excess shoots from a scrog grow, but the
plants can take it. Clip away.
Subsequent pruning is really limited once the plant sets buds and stops
growing. Some plants develop large leaves from the buds themselves, and if
the leaves shade out neighboring bud sites, they must be removed. But that’s
about it. Most of the flowering time in a scrog grow the maintenance level
is near zero.
If everything goes well, the extra time required for the plants to reach the
screen before the flowering period is lengthened by only about two weeks.
No additional time is required to fill the screen, because that time is the
same used by the sea of green method to add height. The plants end up just
as long, but the growth is directed horizontally. Typically a flat scrog
grow ends up resembling a tropical forest canopy, with all the buds in a
thick carpet extending 8-10" above the screen. The area underneath the
screen contains the tree trunks that support the canopy, like piping
connecting the root mat to the canopy.
Does it matter how the canopy is created? Not particularly, in my
experience. There does not seem to be a lot of difference between buds that
would come from sites lower on side branches from those at the actual tip of
the plant. For the most part, a bud is a bud in this method. Note that the
buds grown in a scrog field are each a piece of what would be a vertical
cola. Each bud grows up vertically 90 degrees from the stem. You are
familiar with how a cola is made up of individual bunches of flowers
connected to the stem in an overlapping spiral, producing a structure that
looks like a single unit. In scrog, each one of those florets matures into
a small bud in their own right, typically 4-8" tall, about the size of a
cigar. They aren’t donkey dicks, and you won’t impress the editors of High
Times into featuring your buds in the centerfold, but weight is all we’re
interested in, not appearance. As I say, it all looks the same in the bong
bowl.
How much weight? I have shown that it is possible to reach around 2 oz. per
ft. with a suitable plant and enough light density. I grow at over 100 watts
per foot, and I suspect that 75 watts per sq. ft. is about the minimum to
reach that kind of production, but I don’t know for sure. Understand, that
the HID scrog method has not been around very long, and results are sketchy.
Your results may vary, but certainly you will do better using scrog than
sea of green at any light density. As an experienced sea of green grower,
I feel comfortable stating that as a fact.
What can go wrong? The worst thing you can do is to allow the plants to grow
too long. You would think that excess growth could be cut out or moved to
vertical screens, but in practice I find it’s difficult to recover from a
badly overgrown screen. Plants that grow into and fill the screen seem to
put on better bud weight than overgrown plants that are tied down and
whacked back to fit.
Bog methods
Many people have been excited about the scrog method and have dreamt up all
sorts of ways to expand production, myself included in the mad scientist
crowd. The most common variation is the ``bog’’ method.
Bog for ``box of green’’, was first coined by Kunta and further developed
by chthonic and several other growers. Added to the horizontal screen are
vertical screens around the perimeter. Either additional plants are used at
the edges, or the scrog field plants are grown longer, but either way, the
additional foliage is allowed to grow up the outside of the vertical screen,
taking advantage of wasted air space above the field. It also allows plants
at the edge of the field to get into the circle of intensity from the bulb.
Imagine the light field as a circle sitting tangent to a horizontal line.
Imagine your plant as a point on the line outside of the circle. How can the
plant get inside the circle? By going up. You might equate this method to
an ``arena’’ grow in this regard. An extension on the bog theme is spiral
bog, first coined by chthonic. In a spiral bog the plants are allowed to
add considerable vegetation, which is trained around the box in a laid-down
spiral, like this: //////. This method allows all the screen area to be
densely filled with bud sites.
There are two ways to fill the vertical bog screens, as I mentioned. The
first is to use more plants, which are added to the edges of the grow. When
the horizontal scrog field plants are forced to flower, the plants on the
edge are allowed to grow vertically like sea of green plants, the resulting
growth being trained to the vertical screens. If the growth is too tall for
the screens, it can be laid down at an angle, like a spiral bog grow. The
advantage of this type of bog grow is reliability and speed, since the
horizontal field is filled in exactly the same manner as in a normal scrog
grow. The disadvantage is that the number of plants is increased to near
sea of green levels.
The second method is use the same number of plants as in a standard scrog
grow, or thereabouts, but to allow them to grow longer before forcing,
around another two weeks of growth seems to be about right. This process is
proving to be tricky for me, and I have so far failed to produce a
successful extended bog grow. But other growers are having success, and the
method is superior in theory. Here’s what chthonic has to say about his
experiences with 70 watt HPS lights:
``The quickest and most successful approach that I have found to train a
bog grow is to lower the horizontal screen to within 6" of the soil and
grow 2 plants per sq. ft. straight up to the vertical training screens. As
it's a box driven by a 70-watt bulb, the height from the horizontal screen
to the roof is only 12". The plants grow unhindered 18" from the soil up
through a narrow band of the horizontal screen and onto the verticals until
they touch the roof. Then they are laid down horizontally and trained in a
spiral fashion /// around the vertical training screens. Spiral bog or
s/bog. The cabinet is small; spiral training is the only way to direct the
shoots so it just happens...
``The spiral training can go one of two ways. The entire plant can be bent
over in one direction and trained along with the rest of the plants in a
clockwise or counter-clockwise fashion around the vertical training screens.
Or the plant can be trained as it naturally branched, trained in opposite
directions along the vertical training screens.’’
Any method of growing should be analyzed not only for production over the
space used, but also for production over time. Just for the sake of
argument, let’s suppose a sea of green method produces 1 ounce per ft., and
the subject plant takes 60 days to complete its life cycle. That would
be .017 oz. per ft./day. Let’s suppose a scrog grow takes two weeks longer,
74 days, and produces 1 1/2 oz. That would be .020 oz. per ft/day,
advantage scrog. Let’s suppose than an extended bog grow takes two more
weeks than a scrog grow, 88 days, and produces 2 oz. That would be .023 oz.
per ft. day., advantage extended bog.
Note that it’s possible to shorten the cycle by growing plants in a separate
area for about three weeks and then adding them to the scrog setup. But most
micro and mini growers don’t have room for a separate growing area.
Note that the ``bog’’ term is subject to some debate. Chthonic believes that
the term should be used for a box of foliage that surrounds a light held in
a vertical position. Such a setup can be an outstanding way to get the most
of out small security lights in the 70-100 range. But I think for a larger
light, like a 150 or 250, it is necessary for the light to be in the normal
horizontal position above the box. Personally, your author thinks that bog
can be used as a general term to describe such a grow, and I don’t really
know what other term to use. Chthonic believes this type of grow can be
referred to as an arena grow, but I’ve usually seen that term applied to
free-standing plants rather than a box of screen. Time will tell what terms
become attached to these methods.
Finally, hollow screen forms do not have to be in the shape of
square-cornered boxes. I’ve seen one grower using small HPS lights who
shaped his screen into a deep bowl shape, with the light suspended in the
middle. Recently I read posts on ADPC describing inverted V shapes. A single
``correct’’ way to do this probably doesn’t exist.
At this point, these methods are so new that every grow provides
significant information. My advice to those new to the scrog method is to
get a few fast, flat scrog grows under your belt first to get used to the
process. But do add the vertical screens regardless, and capture whatever
excess growth you can on the verticals, as there is no reason not to handle
as much growth as you can.
V-scrog
The final extension of this concept was thought up by Kunta, and dispenses
with the horizontal screen entirely. I coined the term for the method,
``v-scrog’’, for vertical scrog. Vertical screens extend from the plant
medium all the way up to the top of the growing space. The light is not in a
reflector at the top of the space, but is suspended vertically in the middle
of a tube of foliage, approaching Peg’s Rama concept for zero-g cannabis
growing. Note that the entire light field is used, not just from the bottom
half of the lamp and what comes off the reflector. The foliage area is
stunning. Imagine a 2 x 2 cabinet with a v-scrog screen held 4" from the
walls, with a gap in the front screen for maintenance. Suppose the buds fill
up about 3’ of the vertical screen. We’re talking 4 screens, each 4’ in area
(16" x 36"). Take off a couple of inches for corner overlap and a gap in
the front for access, and that’s nearly 14 sq. ft. of screen in the same
space that supports 4’ of flat screen. Even if the production per foot were
half, and it would be less due to the loss of the 3D flat scrog field,
you’re still talking 3 ½ ounces per foot!
Can that really be possible? We’ll find out soon. I’m aware that chthonic is
working on a setup, and I have all the equipment in place to implement a
full-on v-scrog grow using a 250 HPS and a 220 conversion in tandem. The
potential problems involve the time needed to fill that area, which could
reduce the production over time substantially, and the ability of the root
mat in such a small area to support that much foliage.
Even if production isn’t dramatically better than horizontal methods,
v-scrog is a promising solution to growing in very restricted height
conditions. It might be possible to grow a productive crop in as little as
2’, maybe less. Since the light-to-foliage gap is horizontal, the only
absolute vertical needs are for the plant container and a gap between the
end of the downward-pointing bulb and the planting medium. Plant growth
could be controlled by training it across the vertical screen, which could
be any reasonable height.
Conclusion
Hopefully this will give you an idea of where we stand on small level scrog
methods and will answer some of the basic questions. In spite of the long
history of the use of screens and netting in cannabis growing, accelerated
scrog growing under HID lights is a wide open field, and each new grower
can add experience and ideas to the mix.
Editorial assistance by newbie. Additional input by chthonic and Ultimate
as noted. Thanks to pH, Uncle Ben, Ganja Baron and Teahead for assistance
and suggestions on specific topics. I should also acknowledge indirect
input by Bongo and Shuzzit, as well as the other growers mentioned in the
article.
Fundamentals of scrog growing under small lights
Posted by SCW on August 09, 1999 at 14
36 PT: This article is intended to provide information for new growers using the
``ScrOG’’ or ``Screen of Green’’ method in mini or micro cabinets under
small HPS lights, in the range of 70 to 250 watts. I won’t discuss the
application at 400, 600 and 1000 watts, as that’s outside the scope of my
experience. Refer to Iguana’s site and others for information on what is
called production scrog.
Small HPS lights
Small HPS lights are perfect for growing cannabis in restricted space
conditions, as they produce the most light from a given amount of electricity
of any suitable lamp for cultivation, and produce a spectrum that is
favorable for flower growth. The spectrum is not the best for vegetative
growth, but that isn’t really important to scrog growing, as the vegetative
period is so short. Lights as small as 35 watts are available by stripping
components from security lights commonly available at discount hardware
stores. 250 watt lights can produce as much per foot in scrog conditions as
1000 watt lights in room growing. A single 70 watt light can produce enough
for an average pot smoker in a space as small as 1 sq. ft. MH lights are
available in small sizes, but they produce less light and more heat than
their HPS counterparts, and heat is an important consideration in
cabinet-style growing. Regarding fluorescents, the light to heat ratio is
even worse, and I am not aware of any situation in micro and mini growing
where I would favor them over small HPS lights.
Note that these lights are quite weak compared to 400, 600 or 1000 watt
lights used in production growing. I read a post recently on ADPC where the
question was raised whether two smaller HPS lights were equal to one HPS
light with the same total wattage. The answer is no, and the reason is
intensity. Consider a stream of water coming from a bunch of garden hoses
at normal pressure. You could stand in front of them, right? You’d be wet,
but they wouldn’t knock you down. Now how about the same volume blasting
you in the gut from the nozzle of a fire hose? You’re on your butt. Replace
the fire hose in the example with a 1000 watt light and a group of 70 watt
lights for the bundle of garden hoses, and you get the picture. Intensity
means that the light can be father away from the plant and still be bright
enough at the bud surface to produce. Intensity is necessary for tight bud
formation.
To get the most out of a small HPS light, you must keep the bud sites within
the productive range of the bulb, a lopsided sphere extending out from the
lamp source. For a 250 watt light, that circle of light extends out about
20-24" from the lamp. For a 70 watt light, the maximum distance is
apparently around 8" (per chthonic, who has experience with the lights).
A group of tall, skinny plants under such a light would only be properly
lit at the very tops of the plants, leaving the bottom parts shaded out and
in a low intensity light field, producing small, lightweight buds at best.
Ideally you would like all the buds within that magic circle of light
intensity, and you would like that sphere of light completely filled with
buds. How can that be accomplished?
The scrog method
The essential detail of the scrog method is a screen, usually poultry
netting, typically suspended between the planting medium and the lamp. The
plants grow up to the screen and then are ``trained’’ under the screen,
resulting in a flat table of plant growth, a field rather than a forest.
Because all the buds are growing at the same height, it is possible to get
all the growth within the effective circle of light from the lamp,
maximizing production from the space. It’s really that simple.
Well, nothing new under the sun, the method has been used for years. In
modern terms, the method was first popularized on the internet by the work
of pH on the usenet group Alt Drugs Pot Cultivation, or ``ADPC’’ for short.
You can access ADPC from several web-based sources, and pH still posts there
regularly. But the method as initially used by pH was designed to tweak
production from a large area under fluorescent lights, like the
``multi-shelf’’ method explained in his article on N.P. Kaye’s Lycaeum site.
N.P. Kaye is in fact credited with the term ``screen of green’’, which pH
shortened to ``ScrOG’’.
I am aware of a least one grower who used scrog and HID lights before that
time, based on a mention in Robert Clarke’s book ``Marijuana Botany’’, which
was also a source for pH. But most work involving scrog and HID lights is
quite recent. It is noted by pH that the first ``yield-o-rama’’ post
involving scrog with HID lights was in July of 1997.
Before discussing the method in detail, let’s explore the other alternative
for small HPS lights, the sea of green method.
Sea of green
The sea of green method was developed to maximize the speed of cannabis
growing in limited height situations. In a typical sea of green setup,
clones are planted at densities as high as 9 per sq. ft. Within a short time
after being established, the lights are switched to a 12 hour dark period.
What happens to the planted clone?
The clone could just sit there, stretch a bit under the light regime, and
flower, producing a tiny little bud with a couple of seeds. But that never
happens. Instead the clone takes off in a rush of growth, forming a woody
main stem and branches. If the plant is suitable for sea of green growing,
it will stop short of the lights and flower. Most indica dominated plants
stop short enough to be grown using this method. That process is at the
heart of the sea of green method, as it results in the smallest possible
plant flowering in the quickest possible time.
Why does the clone act in this manner? The actual process is subject to
debate. Your author suspects that the clone reads the light switch as fall,
and has a mechanism that recognizes that it’s too small to produce seed. So
the clone goes into a furious growth mode that stops when the plant reaches
a minimum height set within its genetic software, and then flowers. Others
argue that the clone’s response is just a variation on the normal stretching
process that happens when flowering is forced in any size plant. For
purposes of the discussion here, it doesn’t really matter why the response
occurs, just that you can rely on it.
The problem with the sea of green method under small HPS lamps is that it
produces a number of small spikes under the lamp, a forest rather than a
field. The plants crowd each other out and shade the lower portions, which
in any event are too far from the light source. As we discussed above, tall
and skinny is not productive under a small light. I grew initially using
this method, based on books and magazines that I read before designing my
250 watt system, and it worked well for many years, yielding just over
1 oz. per ft. Not bad, but it can be so much better.
Basic flat, fast scrog
The screen method used by pH relied on a long vegetative period for the
plants to cover a large area of screen held close to a series of fluorescent
tubes. The method I will describe here uses the same sort of growth process
that occurs in a sea of green plant, and is very fast.
The screen should be set about 8-12" above the planting medium. There are
two purposes for that gap. First, you have to get your hands underneath the
screen in order to handle the plant shoots and to remove excess growth
shaded out under the screen. Second, there needs to be sufficient space for
the plant to branch. Branching is essential to scrog. I prefer a space of
about 10" for a 250 watt light, but some growers prefer shorter gaps for
smaller lights, as little as 4-6".
Note that the screen does not have to be absolutely flat, and there are
good arguments for dishing the screen to match the curvature of the light
field. I don’t radically dish my screen, but I do tie down the middle of
the screen to prevent the screen from being pushed up, which would be
counter productive.
The clones are set under the screen at a density of about 1 plant per sq.
ft. Experience in using the method with various types of plants may result
in more or fewer plants, but 1 per ft. is a good starting point. Note that
plant density is much lower than for sea of green. That means less clones
to manage and fewer plants to be holding in a bust, a factor in sentencing
guidelines.
Why clones, by the way? By the time you find out which plants are male and
female from seed, it would be impossible to extract the males from the
foliage wound into the screen and fill in the gaps with female shoots,
without a real mess on your hands. Using seed plants requires modular
methods that are more suited to larger spaces and lights, and is outside
the scope of this discussion.
The clones are established and kicked into vegetative growth. Just about the
time where the growing tips penetrate a few inches above the screen, say at
three weeks, the lights are switched to a 12 hour dark period. Ideally a
response similar to the sea of green method kicks in as explained above.
Instead of stopping and flowering, the plants take off, filling the screen
with growth. At a density of 1 plant per ft., it usually works out that the
plants stop and ``crown off’’ just as the screen is filled. It’s really
magic to see it happen.
The timing is so critical. You must be around during this period to guide
the growth under the screen, and to make sure all gaps in the screen are
filled, one bud site per screen hole with standard poultry netting. Excess
leaf growth must be removed above the screen, which usually means all the
fan leaves are removed. Never mind arguments about whether fan leaves should
or should not be left on plants, this is a different animal, and the rule
here is, all bud sites must see the lamp to develop. At least in a small
scrog grow, fan leaves would overwhelm the neighboring buds. Get a good
sharp, clean set of pruning scissors and just leave them with the grow.
You’ll need them every couple of days during this period.
Training really isn’t difficult. With a limber plant I usually let the
shoots grow vertically above the screen and then pull them under by the
stem, re-orienting the stem horizontally under the screen to line up bud
sites with screen holes. You don’t have to tie anything down, as the upward
pressure of the stem will nail the foliage to the screen, but some growers
like to tie off stems to the screen during the early phases of screen
filling. Here’s what one grower, Ultimate, has to say on the subject:
``I swear by twist ties and have a huge stock. They can be found just about
anywhere. Purchase ties which are most flexible (wire with the smallest
diameter) and coated with plastic not paper, as the paper will eventually
mold.
``So why twist tie? Two reasons when training for in any screen application.
1. Pre-training. (Exact placement of main stems, growth shoots and branches)
2. Bud-training.(Bending, stem crushing/crimping, and repositioning)
``When initially induced to 12/12, the main tip/tips that hit the netting
are immediately trained 90 degrees perpendicular to the netting. This allows
for the light to concentrate the most productive part of the plant, forcing
the most efficient production the plant can dish out. Branches under the
netting are allowed some time to reach the light, but less than half will
see light because you're concentrating on efficiency. The most efficient
growth will occur where the main stem bends on a 90 degree and beyond,
which receives the most light.
``I like to leave the ties long enough for the plant to hold the shape
desired.
Main stem usually around the second week (give or take) , and branches will
always vary. Branches coming off the main stem parallel to the netting are
spread as far from the main stem as possible making for a even canopy, more
bud sites per square, and controlling overall height.
``To a certain extent the buds freeze at a certain point and height/stem
length slows. The canopy height is close to being established, but some
plants are more vigorous than others and continue to stretch beyond the rest
of the crop. When bud training the longer colas are controlled by bending
and tying down to the screen with twist ties. In extreme cases
crushing/crimping is necessary. Moldy buds can be avoided by repositioning
buds growing against each other. By using twist ties each bud can be
positioned where air flows between each cola allowing efficient light
dispersal within the canopy and better air flow.
``Without ties? Yield was lower. A few larger colas had to be tied down
shielding smaller buds from direct light, not to mention forcing the light
to be raised higher, lowering production (This can be resolved by switching
to a more intense bulb) . Some branches grew buds with LONG stems between
the screen and base of the cola to compete with the large colas. Hybrid
vigor in some cases, or plants which tend to "stretch" more than others
eventually straighten out the 90 degree angle exposing less area of the
most efficient portion on the plant and eventually stretches to a point
where more stem was exposed to direct light, above the screen than desired.
A view from the bottom (planter to the screen) showed that efficiency could
be improved.’’
Some plants have brittle stems, and are difficult to train. It is possible
to bend a stem by crushing it lightly at the bend. So long as the structures
in the plant that carry fluids aren’t damaged too much, the shoot will heal
and be just fine (thanks to Uncle Ben for that trick). It may also be
possible to top brittle plants under the screen, so that the future growth
will be in several, more slender shoots. I have no experience in training a
scrog grow by topping.
The second pruning step occurs during and after the screen is filled. All
growth under the screen must now be clipped off. Shaded growth quickly
shrivels and dies, leaving ideal growth mediums for mold. Excess leaves and
shoots should be clipped close to the stem, to avoid leaving stumps as mold
sites. Robert Clarke recommends pruning away from the stem, but a lot of the
standard advice has to be discarded when dealing with the special
conditions of a scrog grow. The space under the screen is dark and humid,
and you want as little plant material under there as possible. You will
haul out buckets of leaves and excess shoots from a scrog grow, but the
plants can take it. Clip away.
Subsequent pruning is really limited once the plant sets buds and stops
growing. Some plants develop large leaves from the buds themselves, and if
the leaves shade out neighboring bud sites, they must be removed. But that’s
about it. Most of the flowering time in a scrog grow the maintenance level
is near zero.
If everything goes well, the extra time required for the plants to reach the
screen before the flowering period is lengthened by only about two weeks.
No additional time is required to fill the screen, because that time is the
same used by the sea of green method to add height. The plants end up just
as long, but the growth is directed horizontally. Typically a flat scrog
grow ends up resembling a tropical forest canopy, with all the buds in a
thick carpet extending 8-10" above the screen. The area underneath the
screen contains the tree trunks that support the canopy, like piping
connecting the root mat to the canopy.
Does it matter how the canopy is created? Not particularly, in my
experience. There does not seem to be a lot of difference between buds that
would come from sites lower on side branches from those at the actual tip of
the plant. For the most part, a bud is a bud in this method. Note that the
buds grown in a scrog field are each a piece of what would be a vertical
cola. Each bud grows up vertically 90 degrees from the stem. You are
familiar with how a cola is made up of individual bunches of flowers
connected to the stem in an overlapping spiral, producing a structure that
looks like a single unit. In scrog, each one of those florets matures into
a small bud in their own right, typically 4-8" tall, about the size of a
cigar. They aren’t donkey dicks, and you won’t impress the editors of High
Times into featuring your buds in the centerfold, but weight is all we’re
interested in, not appearance. As I say, it all looks the same in the bong
bowl.
How much weight? I have shown that it is possible to reach around 2 oz. per
ft. with a suitable plant and enough light density. I grow at over 100 watts
per foot, and I suspect that 75 watts per sq. ft. is about the minimum to
reach that kind of production, but I don’t know for sure. Understand, that
the HID scrog method has not been around very long, and results are sketchy.
Your results may vary, but certainly you will do better using scrog than
sea of green at any light density. As an experienced sea of green grower,
I feel comfortable stating that as a fact.
What can go wrong? The worst thing you can do is to allow the plants to grow
too long. You would think that excess growth could be cut out or moved to
vertical screens, but in practice I find it’s difficult to recover from a
badly overgrown screen. Plants that grow into and fill the screen seem to
put on better bud weight than overgrown plants that are tied down and
whacked back to fit.
Bog methods
Many people have been excited about the scrog method and have dreamt up all
sorts of ways to expand production, myself included in the mad scientist
crowd. The most common variation is the ``bog’’ method.
Bog for ``box of green’’, was first coined by Kunta and further developed
by chthonic and several other growers. Added to the horizontal screen are
vertical screens around the perimeter. Either additional plants are used at
the edges, or the scrog field plants are grown longer, but either way, the
additional foliage is allowed to grow up the outside of the vertical screen,
taking advantage of wasted air space above the field. It also allows plants
at the edge of the field to get into the circle of intensity from the bulb.
Imagine the light field as a circle sitting tangent to a horizontal line.
Imagine your plant as a point on the line outside of the circle. How can the
plant get inside the circle? By going up. You might equate this method to
an ``arena’’ grow in this regard. An extension on the bog theme is spiral
bog, first coined by chthonic. In a spiral bog the plants are allowed to
add considerable vegetation, which is trained around the box in a laid-down
spiral, like this: //////. This method allows all the screen area to be
densely filled with bud sites.
There are two ways to fill the vertical bog screens, as I mentioned. The
first is to use more plants, which are added to the edges of the grow. When
the horizontal scrog field plants are forced to flower, the plants on the
edge are allowed to grow vertically like sea of green plants, the resulting
growth being trained to the vertical screens. If the growth is too tall for
the screens, it can be laid down at an angle, like a spiral bog grow. The
advantage of this type of bog grow is reliability and speed, since the
horizontal field is filled in exactly the same manner as in a normal scrog
grow. The disadvantage is that the number of plants is increased to near
sea of green levels.
The second method is use the same number of plants as in a standard scrog
grow, or thereabouts, but to allow them to grow longer before forcing,
around another two weeks of growth seems to be about right. This process is
proving to be tricky for me, and I have so far failed to produce a
successful extended bog grow. But other growers are having success, and the
method is superior in theory. Here’s what chthonic has to say about his
experiences with 70 watt HPS lights:
``The quickest and most successful approach that I have found to train a
bog grow is to lower the horizontal screen to within 6" of the soil and
grow 2 plants per sq. ft. straight up to the vertical training screens. As
it's a box driven by a 70-watt bulb, the height from the horizontal screen
to the roof is only 12". The plants grow unhindered 18" from the soil up
through a narrow band of the horizontal screen and onto the verticals until
they touch the roof. Then they are laid down horizontally and trained in a
spiral fashion /// around the vertical training screens. Spiral bog or
s/bog. The cabinet is small; spiral training is the only way to direct the
shoots so it just happens...
``The spiral training can go one of two ways. The entire plant can be bent
over in one direction and trained along with the rest of the plants in a
clockwise or counter-clockwise fashion around the vertical training screens.
Or the plant can be trained as it naturally branched, trained in opposite
directions along the vertical training screens.’’
Any method of growing should be analyzed not only for production over the
space used, but also for production over time. Just for the sake of
argument, let’s suppose a sea of green method produces 1 ounce per ft., and
the subject plant takes 60 days to complete its life cycle. That would
be .017 oz. per ft./day. Let’s suppose a scrog grow takes two weeks longer,
74 days, and produces 1 1/2 oz. That would be .020 oz. per ft/day,
advantage scrog. Let’s suppose than an extended bog grow takes two more
weeks than a scrog grow, 88 days, and produces 2 oz. That would be .023 oz.
per ft. day., advantage extended bog.
Note that it’s possible to shorten the cycle by growing plants in a separate
area for about three weeks and then adding them to the scrog setup. But most
micro and mini growers don’t have room for a separate growing area.
Note that the ``bog’’ term is subject to some debate. Chthonic believes that
the term should be used for a box of foliage that surrounds a light held in
a vertical position. Such a setup can be an outstanding way to get the most
of out small security lights in the 70-100 range. But I think for a larger
light, like a 150 or 250, it is necessary for the light to be in the normal
horizontal position above the box. Personally, your author thinks that bog
can be used as a general term to describe such a grow, and I don’t really
know what other term to use. Chthonic believes this type of grow can be
referred to as an arena grow, but I’ve usually seen that term applied to
free-standing plants rather than a box of screen. Time will tell what terms
become attached to these methods.
Finally, hollow screen forms do not have to be in the shape of
square-cornered boxes. I’ve seen one grower using small HPS lights who
shaped his screen into a deep bowl shape, with the light suspended in the
middle. Recently I read posts on ADPC describing inverted V shapes. A single
``correct’’ way to do this probably doesn’t exist.
At this point, these methods are so new that every grow provides
significant information. My advice to those new to the scrog method is to
get a few fast, flat scrog grows under your belt first to get used to the
process. But do add the vertical screens regardless, and capture whatever
excess growth you can on the verticals, as there is no reason not to handle
as much growth as you can.
V-scrog
The final extension of this concept was thought up by Kunta, and dispenses
with the horizontal screen entirely. I coined the term for the method,
``v-scrog’’, for vertical scrog. Vertical screens extend from the plant
medium all the way up to the top of the growing space. The light is not in a
reflector at the top of the space, but is suspended vertically in the middle
of a tube of foliage, approaching Peg’s Rama concept for zero-g cannabis
growing. Note that the entire light field is used, not just from the bottom
half of the lamp and what comes off the reflector. The foliage area is
stunning. Imagine a 2 x 2 cabinet with a v-scrog screen held 4" from the
walls, with a gap in the front screen for maintenance. Suppose the buds fill
up about 3’ of the vertical screen. We’re talking 4 screens, each 4’ in area
(16" x 36"). Take off a couple of inches for corner overlap and a gap in
the front for access, and that’s nearly 14 sq. ft. of screen in the same
space that supports 4’ of flat screen. Even if the production per foot were
half, and it would be less due to the loss of the 3D flat scrog field,
you’re still talking 3 ½ ounces per foot!
Can that really be possible? We’ll find out soon. I’m aware that chthonic is
working on a setup, and I have all the equipment in place to implement a
full-on v-scrog grow using a 250 HPS and a 220 conversion in tandem. The
potential problems involve the time needed to fill that area, which could
reduce the production over time substantially, and the ability of the root
mat in such a small area to support that much foliage.
Even if production isn’t dramatically better than horizontal methods,
v-scrog is a promising solution to growing in very restricted height
conditions. It might be possible to grow a productive crop in as little as
2’, maybe less. Since the light-to-foliage gap is horizontal, the only
absolute vertical needs are for the plant container and a gap between the
end of the downward-pointing bulb and the planting medium. Plant growth
could be controlled by training it across the vertical screen, which could
be any reasonable height.
Conclusion
Hopefully this will give you an idea of where we stand on small level scrog
methods and will answer some of the basic questions. In spite of the long
history of the use of screens and netting in cannabis growing, accelerated
scrog growing under HID lights is a wide open field, and each new grower
can add experience and ideas to the mix.
Editorial assistance by newbie. Additional input by chthonic and Ultimate
as noted. Thanks to pH, Uncle Ben, Ganja Baron and Teahead for assistance
and suggestions on specific topics. I should also acknowledge indirect
input by Bongo and Shuzzit, as well as the other growers mentioned in the
article.
