What nutrients at what stage is important, so pay attention. When a plant is in the vegetating or non-flowering stage their needs are for nutrients that enhance the vegetative process.
The correct nutrients for vegetating your pot plants
Nitrogen is the big key here. Pay close attention to the NPK values of both your soils and your nutrients. You will see there is always a breakdown on the bag or the bottle of NPK; often it looks something like 6-2-2. That means 6 parts of Nitrogen to 2 parts of Potassium to 2 parts of Potash. That is a very good breakdown of a vegetating fertilizer or nutrient. Nitrogen helps your marijuana plant thrive in the vegetating stage, providing the basis for strong healthy leaf and stem structures, root and rhizome structures, and generalized rapid growth. The stronger your plant is before it starts flowering, the better your bud production will be. Phosphorous (P) helps roots and flowers establish themselves, and Potash (K) is important for overall plant health, roots and stems and flowers combined. Be sure to never over do your nitrogen percentage, too much nitrogen will make a plant grow fast, but may also make it grow so fast that the end result is a less healthy plant that is more susceptible to disease and attacks from pests. Monitor the speed and the sturdiness of your plants as they are in the vegetative process, stems should be growing thick and sturdy, as well as tall and leafy. Leaves should be a consistent green all over the plant, and the roots should be well established.
The correct nutrients for flowering, or “fruiting” in your marijuana plants
When you do go into the flowering cycle, whether you are inside or out, you are going to need a different set of nutrients with significantly different aims. If all has gone well, you will be faced with a group of hardy, strong and uniform pot plants before you go into the flowering cycle. An excellent nutrient or amendment for flowering stage is 2-8-2. That is a breakdown of 2 parts Nitrogen to 8 parts of phosphorous, to 2 parts of Potassium. Once again, phosphorous, or P is the big nutrient for getting flowers and root structures to grow strong and be productive. Because the weight of your buds is far heavier than the weight of your leaves, it is important that your root structures are as strong as the rest of the plant.