Marijuana is fertilized at different stages of its growth. No nutrient is required during the germination stage, but once the plant has developed a solid root system and vegetative growth begins, a nitrogen-rich nutrient is introduced. As the plant enters the flowering stage, the needs change to a nutrient with more phosphorus and potassium. Finally, in the weeks leading up to harvest, the nutrient is stopped to allow the plants to utilize the accumulated nutrients, thus improving the quality and flavour of the buds.