← All symptoms
Brown spots
Usually a sign of nutrient burn or a localized deficiency rather than disease, though pattern matters.
Causes, how to tell, and fixes
- 1
Nutrient burn
too much feeding
How to tell
Brown, crispy spots concentrated at leaf tips and edges, often on the newest growth
Fix
Flush with plain water and reduce nutrient concentration on the next feeding
- 2
Calcium or magnesium deficiency
How to tell
Spots scattered across the leaf surface rather than just the edges, sometimes with a rust-colored tint
Fix
A cal-mag supplement is the standard fix, especially common in soilless or coco-based grows
- 3
Leaf septoria or other fungal spotting
How to tell
Circular spots with defined edges, often starting on lower/older leaves in humid conditions
Fix
Improve airflow and reduce humidity; remove affected leaves so it doesn't spread