Hydroponic Screen of Green (SCROG)

A Sea of Green (SOG) is an advanced growing technique used to maximize floor space and grow light utilization when growing marijuana indoors. With so many tiny plants crowded together it looks like a forest or a sea or green plants. A properly done Sea of Green Hydroponics system can give some of the highest GPW (grams per watt) ratios or best yields possible. Plants may be grown as dense as 9 per square foot, though 4 is more common.

Legal Ramifications

All growers must be aware of both state and federal statutes as to number of plants allowed and possible penalties if not in full compliance with local MMJ ordinances.

How to Sea of Green SOG

The main components of the method are:

  1. The usage of marijuana clones to maintain uniformity;
  2. A mother plant or dispensary to provide the clones;
  3. A very short vegging period to limit plant height and bushiness;
  4. Smaller containers.

The weed seed strain chosen is also of great importance as not all strains are suitable for this grow style. Indicas and sativas may be used though hybrids seem to work best, but the most important characteristic to look for is having a single main cola. Wide, bushy plants will defeat the purpose and not allow for the tight packing that single-stem plants will allow.

screen of green hydroponics


A method growing quickly in popularity is to use two liter soda bottles with the top third cut off. Why? They are cheap and can be packed 9 to a square foot (3 X 3) garden. Some have also used 4” round PVC pipe with a cap on the bottom which is great, but somewhat expensive. Tapered containers like a standard flower pot or planter are not used because we are trying to get the most soil or media possible in the smallest area; therefore we want containers with straight vertical sides.

Using this logic, it becomes obvious that the absolute best container would be square to maximize the amount of growing media. The trouble is that commercial square containers are generally too wide and not deep enough.

How deep should the containers be for Sea of Green? That depends on the height of the plants you want to grow, your available grow space height and the amount of media you have available. Generally 6-10” for narrow containers is sufficient for most plants or roughly 1/3 of the plants’ projected finish height.

Grow media is usually soil, coco coir or perlite – sometimes combined with peat or vermiculite. If soilless media is chosen then standard hydroponic nutrients should be used.

Pruning and trimming

Pruning is highly recommended in a SOG to keep your room from becoming a jungle and allowing light to reach almost all the leaves and bud sites. More importantly, we are trying to limit each plant to one main cola so all side branches  and most lower leaves must be trimmed.

When to Flower using Sea of Green Hydroponics

Selected clones should already have decent multiple roots from 3-6” long. To plant they should be held over the center of the container while the grow media is slowly poured in around the roots and cover maybe an inch or two of the lower stem, and then lightly tamped down.

Two weeks under your standard vegging light should give them plenty of time to adapt to the new environment and spread their roots. For fastest turnaround, you may switch to 12/12 under your flowering grow light at this point. A reasonable sea of green harvest when growing marijuana indoors would be about 0.5 ounce per plant or 4.5 ounces per square foot. For larger marijuana flowers, you may veg longer.