Yellow leaves on tomato plants have many possible causes — from nutrient problems to diseases and watering issues. Finding the right reason often takes some research and trial and error. Discovering that your plants have yellow leaves (which can also lead to black spots), catfacing, and other tomato plant problems can be a big disappointment and … The post Yellow Leaves on Tomato Plants – Why are Tomato Leaves Turning Yellow? appeared first on The Gardening Cook.