Sample result
A sample diagnosis: yellow leaves on a tomato plant
[Photos attached] The lower leaves on my tomato plants are turning yellow with brown spots. What’s going on?
Likely causes
| Cause | What points to it | How to check |
|---|---|---|
| Early blight (a fungal disease) | Brown spots with rings like a target, starting on the lowest leaves | Look for concentric rings and yellow halos around the spots |
| Septoria leaf spot | Many small spots with pale centres | Look for tiny dark dots in the centre of each spot |
| Nitrogen deficiency | Even yellowing of older leaves without distinct spots | Check whether the plant has been fed this season |
Try first
- Remove the affected lower leaves and bin them; do not compost them.
- Water at the base in the morning, keeping the leaves dry.
- Mulch under the plants so soil does not splash up onto the leaves.
- Give the plants space for air to move between them.
If it keeps spreading
Your local agricultural extension service can confirm the disease and recommend treatments approved in your area. If you use any product, follow its label exactly.
