Sea of Green gardening, commonly referred to as SOG, is the method of cultivating on a small scale with a large number of plants. Packed closely together, they produce an even and uniform canopy layer of equal height, much like a well kept mowed lawn. There is also a similar and related acronym sometimes used synonymously with sea-of-green called “Screen of Green” – or SCROG. These both share the same principles. It is my objective to define and describe what sets SOG and SCROG gardening apart from other cultivation methods, detailing its many advantages, and few disadvantages.
SOG was first popularized, by no accident, in Europe by indoor gardeners in the early to mid 80’s. It was during this time that indoor cultivators realized that the single largest bottleneck is lighting – our primary source of energy, and most important growth-driving factor. Though we wish we could bring the mighty sun indoors, we are limited to our light source being a 250w, 400w, 600w, 750w, or 1000w High Intensity Discharge (HID) light. With the advent of LEDs, Compact Fluorescents, Plasma, and Induction Lighting – SOG has become ever more feasible than ever before.
To understand SOG and its advantages, we must look at a key principle: The Canopy. As with cultivating any plant, when we harvest, there are parts of the plant that are useful, and others that are considered ‘waste’ or byproducts. Whether we are seeking to harvest the stems, fruits, roots, seeds, juice extract, or flowers from a particular plant, we want to tailor our cultivation method around the goal to maximize our yield of that particular product. The SOG cultivation method was designed precisely to maximize harvesting flowers, and apical or terminal flower buds.
Since we are limited to artificial forms of lighting when growing indoors, the light source is limited to a maximum penetration of no more than 36 inches of canopy. Even when we use the mighty 1000w HID lamp. That is to say, even if I were to grow a 10 foot plant using a single HID source, only the top 36 inches will be green and healthy, and benefit from that light source. The rest will be yellow and starving for light energy.
In nature, we see this principle in the tropical rain forest in South America, where, on the ground, it is actually quite a dark place, being shadowed by immense canopies of very tall trees. Low-light and shade loving plants thrive on the ground. However, near the top of the trees there is quite a different panorama, with totally different wildlife living in the super-bright and sun-baked environment.
This leads us to one key benefit of the SOG method – its quick harvest or ‘turn-around’ time. Since plants are grown and harvested very short (anywhere from 10-20″/25-50 cm) the amount of time spent in the growth stage is greatly reduced. What matters most is not the size of the plant, but the maturity and quality of the final product. It is intuitive to want to grow huge plants, because we know that the bigger the plant, the more yield – per plant. However, growing two, four, six, or eight times as many plants that are half that size or smaller will fill the same canopy space at least twice as fast. Now harvests take place sooner – yielding the same, but taking much less time in between harvests. The turnaround time is greatly reduced, saving you not just time, but electricity, nutrients, and reducing the opportunity for mistakes, and pests and disease.
With SOG, multiple points of light create a more thoroughly even canopy. In the following picture you can see three possible light source scenarios. In SOG cases, bringing the wattage down from one 1,000w to 2-400w or 4-250w light sources will be more effective in increasing light intensity and even distribution of it. The canopy should be horizontal and even.
Air cooled reflectors are the preferred choice in SOG. Generally, we want reflectors that will produce a perfect column of light versus those that spread the light far and wide. I used Hydrofarm’s Radiant 8” in my example. It is an air cooled reflector with a near perfect column of light, that lets me bring a 600w bulb in real close to the canopy. At a distance of only 16” inches away this delivers a powerful blast of 16,500 foot candles of light onto the Sea of Green. That intensity is equivalent to the tropical sun at noon, on a clear sky, near the equator! We can bring the sun indoors after all.
Many SOG growers do not have any vegetative growth period. They simply and literally place their clones right into the flowering stage upon rooting. Others, myself included, only spend a maximum of 3-10 days in vegetative or growth stage (depending on the plant variety) and immediately begin flowering thereafter. Remember we are growing a canopy of flowers, not stems. The usual SOG plant densities are one plant per 6-12 square inches.
There are very few disadvantages to the SOG method. One of the disadvantages is that you require a much larger plant count. The number of plants that can fit in a 4×6 foot tray can easily exceed a 50 count. You will need far more clones (don’t we all) than in traditional cultivation methods. Also, all plants are started and finished at the same time. There is no efficient way of adding plants halfway through for continuous harvest.
As with SOG, the Screen-Of-Green method (SCROG) is also aimed at maximizing canopy space. In this method fewer plants are grown (compared to SOG), but through pinching, super-cropping, bending, trellising, and pruning. Every square inch of the horizontal productive canopy space is filled, creating a “blanket” of green on the screen or trellis. This method is perfect for those who don’t want high plant counts, and have limited vertical space (called working height).
Whichever method you choose, hoist those sails and happy sailing to all my fellow indoor gardeners!
[alert type=white ]This article was written by Carlos Aguila. It was originally published in Garden Culture Magazine, Issue 2 under the title, “Sailing the Sea Of Green”.[/alert]