Although there is still debate over how best to classify the cannabis plant, the most widely-accepted view is that there are three distinct sub-species: Cannabis Sativa, Cannabis Indica, and Cannabis Ruderalis. Breeders often work with hybrids of all three types, creating new and interesting blends which contain genetics that offer a variety of different attributes. Many of your favourite cannabis strains are the result of intensive breeding programs that blend desirable qualities and traits from each of the three different types.
The traits which are generally selected range from the yield of the crop to the aroma of the buds, and by cross-breeding popular or distinctive strains it is possible to combine the best properties of one type of cannabis with those of another. Ruderalis, for example, has an extremely low THC content, so you might think it would be largely ignored by cultivators; but unlike the other two sub-species it flowers at a time determined by the age of the plant, rather than by changes in the length of daylight exposure, and this means that its genes are widely utilised to create the popular “autoflowering” strains which are now very popular with growers.
The cannabis seeds the breeders produce contain the basic recipe for the finished plant (known as the “genotype”), but how it will actually turn out is also dependent on the conditions in which it is grown. The end result is known as the “phenotype”, and it will vary according to the exposure to light, heat, nutrition, water, etc.
Cannabis is a dioecious herb, meaning that it appears in male and female forms, but for the purposes of the majority of cultivators it is the un-pollinated female plant which is most sought after. Many of the seeds available commercially are “feminized”: this does not mean that they will necessarily develop into female phenotypes, but it significantly increases the probability that they will do so.
Reputable breeders will test their seeds regularly to ensure that their feminization technique is as effective as possible, so it’s worth doing a little research on the people who are going to provide your seeds before making a purchase.
The law regarding cannabis seeds can be a strange thing. In many countries, selling or buying the seeds themselves is entirely legal, even though it is illegal to grow an actual marijuana plant. This can be confusing, so if you are purchasing them it is always a good idea to check all the relevant legislation in your country or region. In quite a few places the act of germination is the point at which your seeds become unlawful, so make sure you know what your legal position is before you get yourself in trouble!
To germinate the seeds you simply place them in a warm and moist environment, such as between damp tissues in a room heated to approximately 21C. You should ensure that they are kept away from direct light and that they remain hydrated, then for most seeds you will see roots appearing within 72 hours (although some strains take longer).
Once they have a couple of millimetres of root growth they can be transferred – carefully! – into the growing medium, and as soon as the seedlings proper make their appearance they should be exposed to plenty of bright light. Your seeds are now on their way to becoming fully-grown cannabis plants, and if you give them the care and attention they need then hopefully they will reward you with a handsome crop.