Why Your Plants Have Yellow Leaves (Diagnostic Chart)
Yellow leaves have 6 causes. Old leaves yellowing = nitrogen. New leaves = iron. Wet soil = overwatering. The pattern tells you which.
Yellow leaves are a symptom. The pattern is the clue.
The Chart
| Which Leaves | Pattern | Cause |
|---|---|---|
| Old (bottom) | Uniform | Nitrogen deficiency |
| Old | Between veins | Magnesium deficiency |
| New (top) | Yellow, green veins | Iron deficiency |
| Any | Droopy, wet soil | Overwatering |
| Any | Crispy, dry soil | Underwatering |
| Any | Spots, spreading | Disease/pest |
| Seedlings | Pale, stretched | Not enough light |
The Quick Check
- Old leaves first? → Nutrient or light.
- New leaves first? → Iron or virus.
- All at once? → Water issue.
- Spots spreading? → Disease.
What to Do
- Check soil. Dry or wet?
- Check light. Enough?
- Check age of yellowing. Old vs new.
- Fertilize if nutrient deficiency.
- Treat if disease/pest.
Common Questions
Will yellow leaves turn green? Usually no. New growth will be healthy.
Should I remove them? Only if fully yellow/dry.
Can over-fertilizing cause it? Yes. Flush soil.
Why only bottom leaves? Nitrogen or light.
How long to recover? 1-2 weeks after fixing cause.
Is it dying? Stress, not death. Most recover.