Before you treat a plant, gather the clues.

Name what changed

Write the plant and variety, the date you first noticed the symptom, and whether it affects one plant or several. Record recent weather, watering, feeding, or transplanting. “Lower leaves yellowed after several wet days” is more useful than “the plant looks unhappy.”

Inspect without escalating the problem

Look at both leaf surfaces, stems, the soil, and nearby plants. Take a whole-plant photograph plus close-ups in good light. Check moisture below the surface before watering a wilted plant; wet roots and dry roots can both be associated with wilting. Avoid pulling up the only plant just to investigate its roots.

Separate observation from diagnosis

A hole tells you tissue is missing; it does not identify the cause. A dark area on a tomato may need a different response from a leaf spot. Use a crop-specific diagnostic resource or send your records to a local extension service. Describe the evidence and keep possible explanations separate from established facts.

Make one justified change

Choose a response that fits the identified problem. More fertilizer, pesticide, or water is not a universal rescue plan. If a product is recommended locally, follow its label and applicable rules. Record the action and a follow-up date so you can judge whether the plant’s new growth improves.

Sources & further reading

These extension resources support the growing principles in this guide. Our examples and planning suggestions are editorial explanations. Local recommendations take priority where conditions differ.

• NC State Extension: Vegetable gardening handbook ↗
• University of Maryland Extension: Blossom-end rot of vegetables ↗

Reviewed September 26, 2026. Read our editorial approach.