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The Nutrient Lifecycle of Cannabis: Feeding the Green Goddess

The cannabis plant, like any living organism, has a lifecycle with varying nutritional needs. Understanding the nutrient requirements during each phase of growth not only maximizes yield but also ensures a healthy and potent harvest. Let’s delve into the stages of cannabis’s life and its corresponding nutrient needs.

1. Seedling Stage

The seedling stage is the infant phase of cannabis growth, typically lasting for two to three weeks. Here, the plant’s roots are just beginning to expand and leaves are starting to form.

Nutrient Requirements:

  • Nitrogen (N): Low to moderate. Essential for growth but excessive amounts can burn the young plant.
  • Phosphorus (P): Low.
  • Potassium (K): Low.
  • Micro-nutrients: Minimal.

Key Point: It’s essential to avoid over-fertilization in this stage. Seedlings are delicate and can easily get ‘burned’ by excessive nutrients.

2. Vegetative Stage

In this phase, the cannabis plant focuses on growing in size and stature. This stage can last anywhere from two to eight weeks or even more, depending on the strain and grow conditions and whether it’s an auto-flower or photoperiod plant.

Nutrient Requirements:

  • Nitrogen (N): High. Nitrogen is crucial for this phase as it aids in producing chlorophyll, promoting healthy leaf and stem growth.
  • Phosphorus (P): Moderate.
  • Potassium (K): Moderate to high. Potassium helps with root development and resistance to diseases.
  • Micro-nutrients: Moderate, especially calcium and magnesium which support cell wall structure and enzyme processes, respectively.

3. Flowering Stage

The flowering stage is where the magic happens. Here, the plant begins producing the iconic cannabis buds. Depending on the strain, the flowering stage can last between eight to eleven weeks.

Nutrient Requirements:

  • Nitrogen (N): Low to moderate. While essential in the early flowering stages, too much nitrogen later can hinder bud growth.
  • Phosphorus (P): High. Phosphorus is essential for bud development and boosts flowering.
  • Potassium (K): High. It aids in the synthesis of proteins and carbohydrates, crucial for flowering.
  • Micro-nutrients: Consistent levels of micro-nutrients, including magnesium, which aids in photosynthesis.

4. Late Flowering Stage

As harvest approaches, the plant’s nutrient needs change once again. This stage lasts for about two weeks.

Nutrient Requirements:

  • Nitrogen (N): Very low. Excess nitrogen at this stage can affect bud flavor.
  • Phosphorus (P): Moderate to high.
  • Potassium (K): Moderate.
  • Micro-nutrients: Reduced levels.

Key Point: Many growers practice ‘flushing’ during this phase – a process of only giving the plant water, without nutrients, to wash out excess minerals. This can enhance the flavor and smoking quality of the buds.


As cannabis transitions through its lifecycle, its nutrient requirements shift in tandem. By tailoring nutrient regimes to these shifting needs, growers can achieve optimal plant health, maximum yields, and superior quality harvests. As research and cultivation techniques continue to evolve, our understanding of cannabis’s exact nutritional needs will only deepen, leading to more tailored and efficient feeding schedules for the green goddess.