Sea of Green (SOG) – Harvest more, faster

A photograph of an indoor grow showing a large crop of cannabis plants. They dominate the image. The cultivation method used is known as the Sea of Green.

Growing cannabis is surprisingly simple: all you need are a few seeds, pots, water and light. If, however, you want to maximise yields and also save time, you will do best with a Sea of Green. No other growing approach will allow you to harvest so much in so little time.

The pioneering spirit of the Dutch is the stuff of legends. Want some examples? The telescope and the microscope, stock exchanges, Fairtrade, CD’s, Bluetooth are all Dutch inventions. It was also the Dutch who developed a new way of growing cannabis in the 1970s, which would change commercial growing forever.

We are talking about the Sea of Green method, which combines two major benefits: maximum yields and minimum time invested. Sound too good to be true? Not at all! With a few simple tips, any keen gardener can successfully grow cannabis.

Sea of Green

The cultivation of cannabis indoors presents the grower with the same challenge every time: how do you make best use of the (limited) space available and how do you ensure that the plants get as much light as possible? The answer: Sea of Green.

This approach to cultivation uses a lot of small plants, instead of a few large plants. The growth phase is deliberately kept short, so that the space is completely filled and the light efficiency can be maximised.

Which cannabis varieties are suitable for a Sea of Green?

A photograph showing isolated flowered cannabis plants with their names written above them: Hindu Kush, Northern Lights, Afghani #1, and Super Skunk. They are on a black background.

It is important to use a suitable variety of cannabis and the best idea is to use clones from a single parent plant. This will ensure that the plants all grow in the same way. Growing identical plants for a short period is the main key to success with a Sea of Green.

If you prefer to use cannabis seeds, then make sure they are all of the same variety. Sativas tend to grow too lanky and would impinge on the other plants, but Indicas are more suitable.

The following varieties are particularly appropriate for use as a Sea of Green: Super Skunk, Afghani #1, Hindu Kush and because it is very robust, the classic Northern Lights as well.

Auto-flowering cannabis varieties shift automatically to the flowering stage within a few weeks of germination. They are a popular choice for a SOG. On the other hand, auto-flowering seeds tend to develop a branch structure with a wide reach. In addition, because of their Ruderalis genes, they will never develop buds as large and potent as those from seasonal cannabis.

Going from growth to flowering phase

The ideal pot size is around 15 cm, holding 4 to 6 litres. This means the plants will be fully mature at a height of 30 to 50 cm.

Anyone living in a small apartment, or working with a Micro Grow Setup, will understand the benefits offered by only needing a small vertical space. Experienced growers can even use shelves to stack several growing levels on top of each other.

A common mistake is to assume that the pots need to be placed as close together as possible. This creates a seamless plant surface area, which initially sounds like a great idea. But what this actually means is that the plants are competing directly with each other, with the result that they try to outgrow each other. This “jungle effect” causes stress for the plants, which in turn leads to less biomass or less bud formation.

It is better if the plants do not initially touch each other. The ideal timing for a Sea of Green is not during the first one or two weeks of the vegetation phase, but instead from about the fourth week of the bud formation.

Once the plants begin to grow visibly and the first leaves have appeared, then the seedling phase is over.

Opinions differ as to how long the vegetation phase should last. There are growers who trigger the flowering phase after just a few days, but it is better to wait 10 to 14 days before doing so. The plants are still very young at this point.

If you then change the light cycle to 12 hours of light and 12 hours of darkness, the plants will devote all their energy to creating one main bud. Now is the time to check that the light sources are hanging high enough to avoid creating any hot spots. Incorrectly placing the lamps is one of the most common errors in the cultivation of cannabis.

Uniformity is the answer

A photograph showing a medium close up photo of a large cluster of relatively densely packed cannabis plants. They all seem to be the same species and fill the screen.

Proper care is everything when it comes to successful SOG cultivation. All the plants must be treated equally. This applies to the lighting and supply of nutrients, as well as watering and pruning. Drip systems have proven useful, because they ensure that all plants receive the same quantities of water and nutrients.

It is worth carefully pruning the plants during both the vegetation and flowering stages. If you remove the lower branches, then the plants have more energy to put into forming buds. The goal is for the plants to put all their energy into forming the main bud.

Superfluous leaves and spindly side branches should be removed during the flowering phase. A welcome side effect of this is that it improves the circulation of air.

Important: Great care must be taken with any intervention on growing plants! If you remove too many leaves or branches at once, you run the risk of the plants going into shock and ceasing to grow normally, or producing fewer buds.

Quick summary of the pros and cons of Sea of Green:

+ maximum yields in minimum time

+ multiple harvests per year

+ multiple layers growing above each other

+ not much vertical space required

+ very well suited for commercial growers

+ particularly well-suited for Indica varieties

– Indica and Sativa varieties cannot easily be combined

– more time needed to tend the plants (large number of plants)

– because a large number of plants are needed, you may end up breaking the law

– pests and diseases can spread very quickly

The perfect method of cultivation? There is no such thing!

Every growing method has its pros and cons. Depending on where you are, the available space, equipment, experience, and not forgetting personal preferences, one method or another may be best for you. Getting your hands dirty beats book learning here. It generally takes a few test runs before you master any particular approach to cultivation.

  • Disclaimer:
    Laws and regulations regarding cannabis cultivation differ from country to country. Sensi Seeds therefore strongly advises you to check your local laws and regulations. Do not act in conflict with the law.


15 thoughts on “Sea of Green (SOG) – Harvest more, faster”

  1. The first time I came across the SOG method was in a video , poorly made sometime in the 1980’s. One thing that stood out for me was the successive planting’s for consecutive harvests. To me this is the very meaning of SOG, plants in every stage of growth, with ongoing, unending harvests.

    1. Mark - Sensi Seeds

      Good morning Dark Elf!

      Thanks for your comment,
      I can imagine that would of been great introduction to SOG. Can you remember the video?
      Absolutely, SOG is great way to create uniform plants in locations with limited space, maximizing both light efficiency, and yield.

      You might also be interested in our article on Top 6 Cannabis Plant Training Techniques.

      Have a great afternoon!


  2. I’ve decided to go ahead and try the sea of green method. Now I just need to know what size pots I would need if I plan on growing 15 plants under a 600w light in a 4×4 tent?

    1. Scarlet Palmer - Sensi Seeds

      Hi Richard,

      Unfortunately, legal restrictions mean we can’t answer grow-related questions or give grow advice on this blog. However, other readers of this blog will often answer questions like yours. Sorry I can’t be of more help, and I hope you continue to enjoy the blog!

      With best wishes,


    2. Robert Shaw

      Do 36 in a 4×4 right genetics of course had loads of luck with phantom og and glueberry og u have to hunt the right one down though defo worth it if u find a prize girl

  3. ScrOG or SOG? I’ve never tried either method before, so this will be my first grow using one, or both, of those methods. My grow space is limited, but only vertically, so Indica and Indica dominate hybrids should do well with either method. I’ll post more during my grow with the progress. Thanks for the articles, very informative.

  4. Wolf Segal aka The Farmer in the Sky

    There are several inaccuracies in this story. The first is the claim that SoG was invented by the Dutch in the 70s. It went to Amsterdam in May of ’85 from Seattle, Washington. It was carried there by Greg McAllister (“NL Greg’) who showed it to Ben Dronkers of your ancestor the “Super Sativa Seed Club.” The first time it was mentioned in writing by the name “Sea of Green” is in the 1985 book “Growing Indoors for Fun and Profit,” by the Farmer in the Sky. It was named “Sea of Green” by Herbie N. about a week before the book was published.
    The method described in the article at the link is a “Plantlet” method but it is NOT SoG which is very specifically single cola plants grown at 6-8′ spacin, to be between 1/3 1n1/2 meter tall.

    1. Scarlet Palmer - Sensi Seeds

      Hi Wolf,

      Thank you very much for your corrections and for bringing this to our attention. We are currently in the process of overhauling the blog, and fact-checking and updating articles. I will bring your comment to the attention of the author of this article, and we will amend it as soon as possible. Thanks also for reading our blog!

      With best wishes,


      1. Wolf Segal aka The Farmer in the Sky

        I will be happy to provide photographic proof of the comments I made above, which I do need to alter slightly. “Why?”
        Greg showed the method to Nevil, not Ben. He didn’t meet Ben for several more years.
        Ed Rosenthal can confirm that he didn’t see SoG being used anywhere in Holland during his trips there in the mid-late 70s. Tom Alexander, who published Sinsemilla Tips:Domestic Marijuana Journal from 1980-1990 will verify never having heard of it before hearing about it from The Farmer in the Sky.
        The method was devised based on clues seen in 1979, 1980 and 1981. It was first written about, but not yet named in, if memory serves me properly, 1981, but the name Sea of Green wasn’t attached until 1985, about a week before the book “Growing Indoors For Fun and Profit” went to the publisher. This was the first place the name was attached to the method in print. I do have a copy.

      2. Olivier - Sensi Seeds

        Hi Wolf, thanks for getting in touch with us. We are currently updating all our blog articles and will contact you in due time. Best regards, Olivier

  5. Wolf Segal aka The Farmer in the Sky

    You need to correct the misstatement that it was the Dutch who devised Sea of Green. The first time Ben Dronkers ever heard of the methoid was in May of 1985, when NL Greg carried the method, along with the Northern Lights Collection, to Nevil. Ben showed Greg the Rockwool slab method on that trip as well.
    True SoG is done at 6-8 inch spacings and is meant to be a single-cola of 12-18 inches in height at harvest.

  6. Think this product fits perfect to your article. For modern urban farming. Please have a look at this sexy growbox urbanchili. net Thanks, greatings from Austria

    1. You don’t say much about the box. 65 watts? That only going to yield a oz from that every 3 months . Look at Leaf. That’s who this company copied from . Around same price . Get a white 5x2x2 tent and good lights around $600 for everything!

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    The Sensi Seeds Editorial team has been built throughout our more than 30 years of existence. Our writers and editors include botanists, medical and legal experts as well as renown activists the world over including Lester Grinspoon, Micha Knodt, Robert Connell Clarke, Maurice Veldman, Sebastian Maríncolo, James Burton and Seshata.
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