There are several methods of germinating marijuana seeds. The most popular include the use of cotton wool (cotton buds) or rockwool. Like any other seed, marijuana seeds require water to germinate. Growers will usually pre-soak the seeds in cotton wool or in a damp environment, often in the dark, making sure they keep the seeds moist but not totally wet inside the cotton wool or rockwool. The seeds will usually take a few days or a week to begin to germinate. Growers then carefully transplant the seed after the tip of the root becomes visible. Carefully the seed and root is then put in soil or a hydroponic marijuana medium such as pearlite or rockwool to continue growing.
Below are some examples of marijuana seeds germinating or small seedlings that have just germinated. Growers will often then use a weak light like a fluoro to continue the process until the plant is ready for a more powerful light such as a metal halide.