What's wrong with my plant?
Work through the three checks below first — they resolve most cases, and each one ends with doing nothing. Then describe what you can see.
Before diagnosing anything
- Is it week 6 or later in flower, and only the lower leaves? Fully-fed control plants in a 2023 study began yellowing their lower leaves around week 6 with nothing wrong with them. This is probably normal →
- Are you flushing? Withholding nutrients may amplify or mimic deficiency symptoms. Judge the plant before a flush, not during one.
- What is your runoff pH? Out of range means the nutrient is present and unavailable, and feeding more makes it worse. Check pH first →
Possible causes
Nothing matches that combination. Try removing a filter — the symptom may not be well characterised in the literature, which is itself worth knowing.
These are possibilities, not a diagnosis. Only two controlled studies of nutrient disorders in cannabis exist and they disagree about where several deficiencies appear, so treat any confident symptom chart — including this one — as a starting point rather than an answer.