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Houseplant problem guides

Pick the symptom you see: each guide explains the causes in the order to check them, with a small tool that applies the fix to your plant, from a diagnosis of yellow leaves to a week-by-week pest treatment plan.

When a houseplant goes wrong, the leaves usually tell you before anything else, and the same few causes explain most of what they say. Clemson HGIC sums it up: most houseplant problems come from the environment or the care, not from disease, and over- or under-watering is a major contributor to decline.These guides take one symptom or task at a time and walk through the checks in the order that saves the most plants, drawing on extension fact sheets and on the problem tables of our 80 plant guides. Each one carries a tool for its own question: a diagnosis ranked from those tables, a brown-tip cause finder, an overwatering check, a root rot rescue plan, a pest treatment calendar, a light meter for leggy plants, a pot size calculator and a watering schedule.

  1. Underwatering64% of matches

    Likely why: A small pot dried out in a warm, bright window

    What to do: Soak the pot, move the plant into a larger container, and check the mix often in warm weather.

    Documented on: Basil, Croton, Fittonia, Hydrangea, Mint, Peace lily and 3 more

  2. Cold or chill21% of matches

    Likely why: Cold drafts combined with wet mix

    What to do: Move it away from doors and cold glass, keep it above 61°F, and let the mix drain before watering again.

    Documented on: Calathea, Dieffenbachia, Yucca

  3. Seasonal rest7% of matches

    Likely why: The normal rest period of the bulbs

    What to do: Stop watering, cut off the dead leaves and keep the pot in a cool, dark place for one to three months until new shoots appear.

    Documented on: Oxalis

  4. Too much direct sun7% of matches

    Likely why: A shade cultivar in hot direct sun

    What to do: Move it to bright light without midday sun, or choose a cultivar sold as sun-tolerant.

    Documented on: Coleus

Ranked from the problem tables of our plant guides, each sourced on its page. A ranking of likely causes, not a certainty.

Every guide

  • Yellow leaves: Most yellow leaves on a houseplant trace back to too much water: soggy mix starves the roots of oxygen and the plant sheds its oldest leaves first. Push a finger 2 inches into the mix. Wet means stop watering and look at the roots; dry means check light, feeding, pests and age.
  • Brown leaf tips: Brown leaf tips usually mean the leaf edge is the first place salt, fluoride or dry air does damage. Look for a white crust on the soil, think about your water and your heating, then flush the pot with plain water. The brown parts stay brown; new leaves show whether the fix worked.
  • Overwatering vs underwatering: An overwatered plant droops with soft, limp leaves while its mix is still wet and the pot feels heavy. An underwatered plant droops with dry, crisp leaves in a light pot of dry mix. Feel the mix 2 inches down before adding water: wilting in wet mix means stop watering.
  • Root rot: Root rot shows as wilting in wet mix, a sour smell, and roots that are brown to black and soft instead of firm. Unpot the plant, rinse the roots, cut every rotten one back to firm tissue and repot in fresh, sterile mix. If most roots are dead, root cuttings instead.
  • Pests: Most houseplant pests ride in on a new plant. Spider mites leave pale speckles and fine webbing, fungus gnats are tiny flies breeding in wet mix, and mealybugs look like white cotton in leaf joints. Isolate the plant, treat once a week for several weeks, and let the mix dry out to stop gnats.
  • Leggy plants: A leggy plant has long, bare stems with small leaves spaced far apart, and the cause is almost always too little light. Move it closer to a window or add a grow light, then cut the stretched stems back above a leaf node. Old stretched growth never tightens up; only new growth does.
  • Repotting step by step: Repot in spring or early summer, when the plant is growing. Pick a pot 1 or 2 inches wider with a drainage hole, slide the plant out, loosen or cut circling roots, set it at the same depth in fresh potting mix, press gently and water until it drains.
  • How often to water: There is no fixed schedule. Water when the plant's own drying test says so: most houseplants when the top inch or two of mix feels dry, succulents only when the pot is dry throughout. Pot size, clay, light, season and humidity stretch or shorten the interval, which the calculator below estimates.

Where to start when you are not sure

Check the mix, then the light, then the leaves. Push a finger two inches into the pot: soggy mix days after watering points to the overwatering and root rot guides, bone-dry mix and crisp leaves to the watering guide. Then ask whether the plant has moved or the season has changed, which explains stretching, leaf drop and slow growth. Only then turn the leaves over and look for webbing, cotton or tiny flies, the work of the pests guide. The diagnosis tool above runs the same order of questions against our plant data.

Questions people ask

What is the most common reason houseplants die?

Overwatering. Clemson HGIC calls it the main cause of death of potted plants: roots surrounded by water cannot take up oxygen, rot, and the plant collapses. The confusing part is that a rotting plant wilts as if it were thirsty, so many owners water it again. Check the mix two inches down before you reach for the watering can.

How do I know if a houseplant problem is a disease or my care?

Start by assuming care. Clemson HGIC notes that most houseplant problems have environmental or cultural causes, and that diseases are uncommon indoors because conditions do not favor pathogens. Rule out water, light, temperature, salts and pests first; suspect disease when spots spread with a yellow halo or ooze, or when roots are brown and soft.

Should I isolate a sick plant from my other houseplants?

Yes, when pests are involved. Clemson HGIC advises isolating any plant suspected of carrying pests until they are completely controlled, which can take several weeks, and quarantining new plants for six weeks before they join the others. A plant suffering from water or light problems is not contagious and can stay where it is.

How long does a houseplant take to recover after I fix the problem?

Expect weeks, not days. Damaged leaves do not heal; recovery shows as healthy new growth, which comes faster in spring and summer than in winter. Clemson notes that leaf drop after a change of environment should only last about three weeks, so a plant still declining after a month needs a second look at the cause.

Can I save a plant that has lost most of its leaves?

Often, if the roots and stems are firm. Cut back dead stems, keep the plant in bright indirect light, water only when its drying rule says so, and skip fertilizer until new leaves appear. If the roots are mostly brown and soft, take healthy cuttings instead: our root rot guide walks through the decision.

Why do my plant leaves turn yellow after repotting?

A few yellow leaves after repotting are usually shock: some roots were disturbed and the plant sheds older leaves it can no longer supply. Clemson HGIC advises against repotting ailing or dormant plants for this reason. Water once thoroughly, then let the new mix dry to the plant’s depth; fresh mix in a bigger pot stays wet longer.

Related plants, guides and tools

Plant problem diagnosis

The full symptom tool

All plant guides

Problems table on each

Sources

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