The first step is to prepare bottles with a fertile soil. Choose some big lab bottles or milk bottles with a wide neck and disinfect them with boiling water. Your first task will be to prepare a nutritive medium. Here is a sample recipe, others may vary:

1000 ml distillated water, 2 gram yeast extract, 4 gram peptone, 10 gram white sugar, 10 gram agar and 10 drops of polybione, a vitamine preparation.

Heat the ingredients and fill them hot into the prepared bottles. Close the bottles and lay them on the side. The nutritive soil will cool off and become a jelly-like substance. The result should look like the illustration below.

If you don't have access to a sterile room, the greatest problem will be to get the seeds into the bottle without getting it infected with unwanted spores.