Chat GPT is great
Symptom picture:
• Significantly yellowing lower leaves, starting at the leaf tips and slowly spreading
• The veins remain green, the surrounding tissue yellows (interveinal chlorosis)
• Some brown necrosis at the edges
• Affects only older, lower leaves – everything looks healthy above
⸻
Most likely cause:
Classic nitrogen deficiency (N)
• Plants draw nitrogen from old leaves during the flowering phase or when nitrogen is scarce → typical yellowing from bottom to top
• In organic grows, this is often normal in late flowering, but:
• If it occurs too early, it slows growth and later reduces flower formation
• Deficiency also occurs when:
• The soil life does not mineralize quickly enough
• The plant is particularly hungry (e.g., during stretch)
• The substrate is depleted and no longer supplies enough
⸻
Differential diagnosis (less likely here):
• Magnesium or potassium deficiency → would show other signs (e.g., spots or edges affected first)
• Overwatering → would rather show in drooping and general lethargy
⸻
Solution approach (organic):
Short-term:
• Liquid, quickly available organic nitrogen
e.g., with:
• Worm tea / worm compost extract
• Fermented plant juice (e.g., nettle or alfalfa ferment)
• Organic nitrogen fertilizer like BioBizz Fish-Mix or TopMax
Long-term:
• Activate soil life:
• Compost tea
• Effective microorganisms (EM)
• Top-dressing with compost or worm humus