What should be checked first to determine if a plant is diseased?

Checking the leaves for discoloration or spots is crucial as the leaves are often the first part of the plant to exhibit symptoms of disease. Many plant diseases, especially those caused by fungal and bacterial infections, manifest through changes in leaf appearance. Discoloration can indicate various issues, including nutrient deficiencies, exposure to pests, or specific infections. Additionally, spotting can reveal more about the type of disease affecting the plant, such as leaf spot diseases or the effects of environmental stress.

While inspecting roots for wilting, stems for brittleness, or checking soil for moisture are also important aspects of plant health assessment, they may not provide as immediate or clear indicators of a disease as leaf examination does. The leaves typically respond more visibly to health issues, making them a logical starting point in the diagnostic process.