(Image credit: Getty Images) A lemon tree is one of the most rewarding things you can grow at home — fragrant flowers, glossy leaves, and the occasional actual lemon if conditions are right. They're also more communicative than most plants, and once you learn to read the signs, caring for them becomes a lot more intuitive. Yellowing leaves are one of the most common concerns, and one of the most misread. One day the plant looks fine; the next, something is clearly off and it's not obvious why. In most cases, the cause is straightforward and the fix is simpler than you'd expect. You just need to know where to look. 1. Overwatering The most common culprit. If leaves are yellowing and dropping while the soil feels wet, the roots are likely drowning, or already rotting. Check the soil before every water . Push your finger two inches in and if it's still damp, leave it alone. Also ensure your pot has drainage holes and empty the saucer after watering .…