Ignore them and pretend they don’t exist? Use our visual guide to diagnose tomato leaf problems—plus tips on resistant varieties and prevention. So what’s going on? Well, sometimes it’s no big deal. · yellow leaves ? Find out the difference between normal seed leaves, watering problems, soil compaction, transplant shock, diseases, nutrient deficiencies, and more. It’s often something you can fix once you know what to look for. · if you’re growing tomatoes (whether it’s your first year or your fiftieth), you’ve probably noticed that as the season progresses, the leaves towards the bottom of the plant turn yellow. · it’s easy to feel like you’ve done something terribly wrong, but yellowing leaves are actually your plant’s way of waving a little flag for help. Should you panic? · learn why your tomato leaves are turning yellow and how to fix it. · are your tomato leaves turning yellow ? To figure out why tomato leaves turn yellow , we spoke with experts to understand this gardening mystery.