Yellow Tomato Leaves: A Field Guide to Diagnosing the Real Cause

Yellow leaves can mean five very different things — from a simple watering mistake to a virus that ends your season. Here is how to tell them apart in five minutes.

Tomato is one of the highest-value crops a smallholder can grow — and one of the most fragile. A wrong diagnosis of yellow leaves can mean spraying the wrong chemical, losing a week of growth, or in the worst case, losing the whole crop.