A plant dropping one old leaf is normal. A plant dropping leaves like it just heard bad news is not. Leaf loss is a general stress signal, so the pattern matters.
Quick Answer
Plants lose leaves because of watering stress, low light, temperature shock, transplant shock, pests, or natural aging. Sudden leaf drop usually means a recent change upset the plant.
Normal Leaf Drop
Older lower leaves naturally die as plants grow. If the plant is producing healthy new growth and only drops an old leaf occasionally, do not start a rescue mission.
Watering Stress
Both overwatering and underwatering can cause leaf drop. Wet soil plus yellowing points toward overwatering. Dry soil plus crispy leaves points toward underwatering.
Low Light
In low light, plants cannot support as much foliage. They may drop older leaves to conserve energy. Move the plant closer to a bright window, but avoid sudden harsh direct sun.
Shock
Repotting, moving homes, cold drafts, heat blasts, or a new location can trigger leaf drop. Keep conditions stable and give the plant time.
Pests
Sticky residue, white fuzz, webbing, or speckled leaves can signal pests. Check stems, leaf undersides, and new growth.
What to Do
Check soil moisture, inspect leaves and stems, review recent changes, and improve light if needed. Avoid changing five things at once. Plants appreciate care, not chaos.
Bottom Line
Leaf drop is a clue. Match the timing and pattern to watering, light, shock, or pests before deciding what to fix.