Diagnose a Plant Problem
Most houseplant symptoms have several possible causes, and the treatments are often opposite. Start from what you can see and work through the causes in order of likelihood.
Brown, crispy leaf tips
Brown tips are usually low humidity or mineral build-up from tap water, not thirst. Switch to filtered water, raise humidity, and flush the pot to leach out salts.
Most likely: Low humidity · 6 causes covered
Work through it →Tiny black flies around plant soil
Confirm the flies are fungus gnats, then address the damp potting mix where larvae develop. Use yellow sticky traps to monitor adults. If needed, choose a larval treatment labeled for fungus gnats on indoor potted plants, such as an appropriate Bti product.
Most likely: Potting mix staying damp · 2 causes covered
Work through it →Monstera leaves with no holes or splits
Monstera leaves may stay solid because the plant is young or receives too little light. Check maturity and light first, then provide climbing support. Existing solid leaves will not develop natural splits later; look for changes in new growth.
Most likely: A young plant or juvenile new growth · 3 causes covered
Work through it →Wilting, yellowing, but which cause?
Feel the soil two inches down and squeeze a leaf. Damp soil with soft limp leaves means overwatering. Dry soil with crisp papery leaves means underwatering.
Most likely: Overwatering · 4 causes covered
Work through it →Root rot
If a plant wilts while the potting mix remains wet, inspect the roots. Healthy roots are firm; rotted roots are soft and discolored. Remove affected tissue, use a clean container and well-drained mix, then avoid keeping the root zone saturated.
Most likely: Overwatering · 6 causes covered
Work through it →Leaves turning yellow
Check the potting mix first. Persistently wet soil points toward root stress, while very dry soil, low light, pests, nutrients and normal leaf ageing can produce similar yellowing.
Most likely: Overwatering · 7 causes covered
Work through it →Drooping or wilting leaves
Check the soil before watering. Dry soil means thirst, so water and it recovers in hours. Wet soil means root rot, and watering again makes it worse.
Most likely: Thirst · 6 causes covered
Work through it →Long bare stems, widely spaced leaves
Legginess is almost always insufficient light. Move the plant closer to a window or add a grow light, then prune the stretched growth, because it never re-compacts on its own.
Most likely: Not enough light · 5 causes covered
Work through it →White cottony clusters on leaves and stems
Isolate the plant, remove the mealybugs you can see by hand, rinse it and prune out heavily infested stems. If you need a product, choose one labeled for mealybugs and indoor use and follow the label. Keep inspecting weekly, because eggs and hidden insects often survive the first round.
Most likely: A newly bought plant · 4 causes covered
Work through it →Fine webbing and stippled leaves
Isolate the plant now, because spider mites spread fast. Shower it thoroughly, then treat with an insecticidal soap or horticultural oil labeled for mites on indoor plants, repeating as the label directs to catch each new hatch.
Most likely: Hot, dry air · 4 causes covered
Work through it →Shell-like bumps on stems or leaf veins
Isolate the plant and inspect leaf undersides, veins and stems for attached scale insects. Remove small infestations gently, prune heavily affected growth where practical, and monitor new growth. If treatment is needed, choose a product labeled for scale on indoor plants.
Most likely: Scale insects attached to the plant · 3 causes covered
Work through it →White fuzz or crust on the potting mix
Soft white fuzz on damp potting mix is usually a fungus feeding on organic matter, and it is not necessarily harmful to the plant. Scrape it off, let the surface dry as far as the plant tolerates and improve airflow. A hard, crunchy crust is more likely salt buildup, which needs flushing instead.
Most likely: Fungal growth on damp, organic-rich mix · 4 causes covered
Work through it →The two checks that solve most problems
1. Feel the soil, two inches down
Not the surface. The surface dries within a day of watering and tells you nothing. Damp at two inches means stop watering. Bone dry means water thoroughly. This single test resolves the majority of yellowing, drooping and wilting cases.
Overwatering vs underwatering →2. Be honest about the light
At midday, could you comfortably read a book in that spot without a lamp? If not, it is a low-light position no matter how bright the room feels. Light intensity falls off with the square of the distance from the window.
How to measure light →