The most important phase of the marijuana plant life cycle is the first two weeks. This is when the plant's basic structure is formed and where you can make the most difference to how the plant will perform when it is fully-grown.
The first two weeks are when you need to do everything possible to encourage the plant to grow. This means, as much light as possible and nitrogen rich, fertilizer. The marijuana plant needs the nitrogen and light to power its growth. It is also important that you don't use flowering style fertilizers that are phosphor and potassium based because they will not have the nitrogen that the cannabis plant needs. This can be seen by slow growth and yellowing of the leaves.
The initial growth is followed by the formation of the flower structure. This is sometimes called the first flowering and since this is, where to buds and flowers will form when the plant matures if they are not taken care of, then yield will decrease and you will be sad. Regular use of smaller doses of nitrogen-based fertilizer will ensure the best growth and limit the chance of burning that just dumping a single large amount of fertilizer may cause. Yes it does take lots of work to get the best results but you will reap the rewards a few months down the track.
You may notice that the plant start to concentrate its growth in height and after a few days stamens and pistils start to form. This is a sign that the growth has stabilized and that you can start to cut back on the fertilizer that you are giving the plant.
After a week or two this will become a solid structure that you can easily identify the areas that the buds are situated. To get the most from the buds, and to ensure the highest yield it is important to remove any of the buds that are below the top and not likely to get good light. The buds in full light will now get the full force of the plant nutrition and the amount of leaves will also be less than if you didn’t prune the other buds.
It is also a good idea not to cut any leaves on the plant unless they turn yellow. The plant needs its leaves to properly convert light into energy. If you leave the buds on the lower parts of the tree and cut the leaves to give them better light then you may well get more buds but they will be sharing a much smaller part of the plant nutrition. This means they will not develop as well and most likely will have far less active THC in them.
I hope this guide has been helpful to you in understanding the importance of getting the cannabis plant of to a good start. The care and attention you show the plant as it forms will be rewarded when you harvest it. Enjoy.