I DO NOT TAKE CREDIT FOR THIS! I found this on smaller site about marijuana growing (hg420.com posted by lexaken). I didn't find anything about SoG on this site. This should be a sticky. Fundamentals of Small-scale Scrog Growing from a thread from the dead OVERGROW forum written by Tyler Freeborn Table of Contents 1.0.0 The Grow 1.1.0 Introduction 1.3.0 The Scrog method 1.3.1 Sea of green 1.3.2 Basic flat, fast scrog 1.3.3 Vegetative fills, FIM and topping 1.4.0 Interrupted flowering 1.5.0 Bog methods 1.6.0 V-scrog 1.7.0 Soil or hydro? 1.8.0 First-time growers, fluorescent lights 2.0.0 Basic design elements 2.1.0 Lights 2.2.0 Cabinet 2.2.1 Fans 2.2.2 The Netting 2.3.0 Caution 3.0.0 Conclusion 1.1.0 Introduction 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 spend too much time on 400, 600 and 1000 watt grows, as that's outside the scope of my experience. See the ``links” post below for further materials regarding 400 watt and other scrogs. 1.3.0 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 two growers who used scrog and HID lights before that time, one 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 for HID scrog was in July of 1997. I became aware of the method from a medical grower in the final days of the Hemp B.C. boards, Savapalet, a posting buddy of Aeric 77. Before discussing the method in detail, let's explore the other alternative for small HPS lights, the plantlet sea of green method. 1.3.1 Sea of green The plantlet sea of green method was developed to maximize the speed of cannabis growing in limited height situations. In a typical sea of green setup of this type, 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 rarely, if ever, 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 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. Note that in the mid-90's, the term ``sea of green” started being applied to much larger plants and grows, even multiple 1000 watt installations over room-sized grow tables, with 3 foot plants spaced at one per foot. It seems the original meaning of the term, the SSSC plantlet method, has been almost forgotten. 1.3.2 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 plantlet method sea of green plant, and is very fast. The screen should be set about 8-12" above the planting medium, if possible. 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 plantlet-method sea of green. That means fewer 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. Seed plants also waste several inches of height before a mature stem section is reached from which branching can begin, whereas clones branch right from the medium. Height control is typically a limiting factor in cabinet growing. With female seeds it may be possible to grow a predictable scrog by raising the screen height, making up for the wasted stem length. Seed plants may react differently to forcing as well. I have no experience in scrog from seed. The clones are established and kicked into vegetative growth. Assuming an 8-12" gap, just about the time where the growing tips penetrate a few inches above the screen, say at two 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. Note that this timing method is not universal. Different plants may require more vegetative growth, or perhaps even less. My advice is to start by forcing early, because overgrowth creates an unproductive canopy, more salad than buds. 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 (2 x 3 inch holes). I have no position on removing fan leaves in general, but in a small scrog grow, fan leaves would overwhelm the neighboring buds, and normally they are removed. 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. Note that some growers disagree, so feel free to experiment. I'm no expert on the matter, but I haul out tubs of leaves and get pretty decent results, I think. 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 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 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. After the screen is filled all growth under the screen must 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, I find 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 over 2 oz. per ft. with a suitable plant and enough light density. 400 watt growers have reported up to 2.4 ounces per foot in a flat scrog. In a compressed grow, using shielded lights in a box of screen, I did nearly 2.6 ounces per foot, measured by canopy area. I suspect that 70-75 watts per sq. ft. is about the minimum to reach that kind of production, but I don't know for sure. Your results may vary, but certainly you will do better using scrog than small-scale sea of green at any light density. As an experienced plantlet-method sea of green grower, I feel comfortable stating that as a fact. Anyone can reach the benchmark production numbers, but you must concentrate on filling the screen quickly and completely. If loose and tall would yield better, then scrog wouldn't work in the first place. You want the canopy to be low and tight, except on the edges, and one bud per hole. Screen fill density is all important to making weight. A side note regarding the measurement and reporting of production is appropriate here. For the most part, growers on the boards talk in terms of so many ounces per square foot of growing area, apologies to the metric system. Some growers feel it is more appropriate to measure production in terms of HPS watts, taking into account how efficiently the grower uses the lamp, and our host, ~shabang~ has proposed a ``garden efficiency” measurement, or ``GE”. In cabinet growing the area under cultivation cannot be expanded, and the lamps are typically very small, especially in comparison to any kind of production grow. I believe measuring output per watt would favor underlit grows, given an equal amount of space being used. Cabinet growers want to know how to produce the greatest weight of buds in the space they have, not how to conserve lamp power. Indeed, a cabinet grower should use the greatest amount of lamp power than can be cooled. Accordingly, I favor reporting production by area, but I encourage reporting a complete set of information about the grow so that light density can be taken into account by those so inclined. A ``yield-o-rama” report or ``YOR” is a good compromise. You can find information about the YOR on the usenet group ADPC in posts by Old Ketchup Lungs and other posters. What can go wrong with a flat scrog grow? 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. Error on the side of forcing early, learn from what happens and adjust on the next crop.