Nutrient Science

How cannabis plants take up, use and lose nutrients — from nitrogen form to flushing, from deficiency signs to toxicity thresholds.

• Boron Deficiency in Cannabis – the Role of Boron in the Cell Wall, Symptoms, and the Limits of Diagnosis

  What role boron plays in the plant cell wall, how a deficiency presents itself, and why the gap between requirement and toxicity is narrower for this element than for almost any other.

• Calculating a Nutrient Solution: Working Out Milligrams per Litre from Label and Irrigation Water

  Fertiliser label, dose and irrigation water together give the concentration of each nutrient element in milligrams per litre, and the target ranges it is compared with come from trials with one or two varieties per study.

• Cannabis Flushing – Withholding Nutrients Before Harvest and What It Actually Does

  What flushing means in cannabis cultivation, which controlled studies have tested its effects, and why the data looks quite different from what growers expect.

• Feeding and Root Volume: Their Influence on Flowering Onset, Duration and Plant Size

  Too much nitrogen pushes flowering onset back, too little does the same, and in between sits an optimum whose position depends on the growing system.

• Identifying Nutrient Deficiency in Cannabis – by Location on the Plant, Leaf Tissue Analysis, and Substrate Solution Testing

  Where on the plant a nutrient deficiency first becomes visible in cannabis, why describing the symptom alone is not enough, and which two laboratory analyses secure the diagnosis.

• Leaf Senescence in Cannabis – the Programmed Ageing Process During Flowering

  What leaf senescence in cannabis is physiologically, how it becomes visible during flowering, and why it is regularly mistaken for a nutrient deficiency.

• Nitrogen (N) – an Important Nutrient for Cannabis Growth

  This article covers the role of nitrogen (N) in cannabis growth, how to identify nitrogen deficiency and overfeeding, and how to optimise nitrogen uptake.

• NPK Ratio in Cannabis: Basics, Myths, and Evidence-Based Recommendations

  Evidence-based analysis of the optimal nitrogen-phosphorus-potassium ratios for Cannabis sativa – from tissue analysis to phase-specific recommendations and the classification of popular fertiliser systems.

• Nutrient Lockout in Cannabis – a Practical Term for Four Very Different Causes

  What nutrient lockout means, why the term confuses more than it clarifies, and which four mechanisms – pH, ion antagonism, salt pressure, and root-zone temperature – hide behind it.

• Nutrient Oversupply in Cannabis – What the Controlled Fertilisation Studies Show

  What controlled cannabis studies show about the upper limit of nitrogen, phosphorus, and potassium supply, and why a higher rate does not automatically mean more yield, let alone more potency.

• Silicic Acid in Cannabis – Uptake, Deposition in the Tissue, and the Question of the Source

  How cannabis takes up silicon, in which tissues it is deposited, and why with silicic acid products the solubility of the source matters more than its silicon content.

• Water Quality and Nutrient Solution in Coco Coir: Why the Water Source Decides the Outcome

  Demineralised water as the basis of a nutrient solution regularly causes problems in coco coir that look like overfeeding but have a different cause.