Germinate seeds in sterile soil (for planting outdoors) or a hydroponic medium of rockwool or vermiculite. DO NOT (!) use a Jiffy cube #7 to germinate seeds. Informal tests and experience show these peat cubes do not work well and stunt the plants growth. Planting in vermiculite gives the seedling so much oxygen, and are so easy for roots to grow in, that the plants look large 1 week after germination!
Keep them moist at all times, by placing seeds in vermiculite filled 16oz cups with holes in the bottom, placed in a tray of weak nutrient solution, high in P. Rockwool cubes also work extremely well. When the seed sprouts, place the rockwool cubes into larger rockwool cubes. No repotting or transplanting, and no soil mixing!
You can germinate seeds in a paper towel. This method is tricky; it is easy to ruin roots if they dry out, or are planted too late after germinating. Paper towels dry out REAL FAST! Place paper towel in a bowl, saturated with weak nutrient solution (not too much!), and cover with plastic wrap to keep it from drying out. Put bowl in a warm area; top of the gas stove, water heater closet, or above warm lamps. Cover with black paper to keep out light. Check every 12 hours and plant germinated seeds with the grow tip up (if possible) in a growing medium as soon as the root coming out of the seed is 1/16″ or longer. Use tweezers, and don not touch the root tip.
Transplant as little as possible by germinating in the same container you intend to grow the plant in for a significant period of time. Just plant in vermiculite or rockwool. You will be amazed at the results! 90% germination is common with this method, as compared to 50% or less with Jiffy Cubes. (Your milage may vary.)
5-55-17 plant food such as Peters Professional will stimulate root growth of the germinating seed and the new seedlings. Use a very dilute solution, in distilled water, about 1/3 normal strength, and keep temperatures between 72-80 degrees. Warm temperatures are very important. Many growers experience low germination rate if the temperatures are out of this range. A heating pad set to low or medium may be necessary, or a shelf constantly warmed by a light may do, but test it with a few seeds first, before devoting next years crop to it. No light is necessary and may slow germination. Cover germinating seeds with black paper to keep out light. Place seedlings in the light once they sprout.
Plan on transplanting only once or twice before harvest. Use the biggest containers possible for the space and number of seedlings you plan to start. Plants will suffer if continuously transplanted and delay harvesting. You will suffer too, from too much work! 13 2-liter plastic soda bottles filled with vermiculite/pearlite will fit in a cat box tray, and will not require transplanting for the first harvest, if you intend to grow hydroponically. Transplant them for a second regenerated harvest.
Cut holes in the bottom of containers and fill the last few inches at the top with vermiculite only, to start seeds or accept seedling transplants. Since vermiculite holds water well, wicks water well, but does not hold too much water, roots always have lots of oxygen, even if they are sitting in a tray full of water. A hydrogen peroxide based plant food is used to get extra oxygen to the plants when the pans are kept continuously full. The water can be allowed to recede each time after watering, before new solution is added. This allows the plants roots to dry somewhat, and make sure they are getting enough oxygen.
Use SuperSoil brand potting soil, as it is excellent and sterilized. If you insist on using dirt from the yard, sterilize it in the microwave or oven until it gets steamy.(NOT RECOMMENDED) Sterilize the containers with a bleach solution, especially if they have been used a previous season for another plant.
Article written 2004 and featured on Grow-Marijuana-Seeds.com