N-P-K refers to the primary nutrients required for growing high quality cannabis and other plant products in the agricultural industry and refers specifically to:

  • Nitrogen (N) – especially important for photosynthesis and although nitrogen is present in the atmosphere, most plants require nitrogen in the soil to absorb it through their roots.
  • Phosphorus (P) – a key nutrient for the development of strong roots and is typically increased for healthy bud development during the flowering stage.
  • Potassium (K) – helps to strengthen a plant’s immune system and metabolism to provide greater resilience against disease, pests, and infections.

Cannabis fertilizer products will indicate the ratio of these nutrients included in their products noted as N-P-K. Most growers favor a nutrient mix higher in nitrogen such as a ratio of 3:1:1 during the vegetative growth stage. Nutrient requirements change during the flowering stage with the recommended ratio more aligned with 1:3:2 and ending in 0:3:3 during the late bloom period.