Why Are My Plant's Leaves Turning Yellow? (7 Causes & Fixes)

Don't panic — but do investigate

A few yellow leaves on an otherwise healthy plant is perfectly normal — plants shed old leaves continuously. But if yellowing is spreading, affecting new growth, or accompanied by other symptoms, something's wrong. Here are the seven most common causes, in order of likelihood.

1. Overwatering (most common)

Yellowing, mushy, or translucent leaves combined with wet soil and a musty smell = overwatering. This is the number one cause of houseplant decline. The fix: let the soil dry out completely before the next watering, improve drainage, and check roots — brown, mushy roots mean root rot, which needs urgent action (remove affected roots, repot into fresh dry soil).

Test: Push your finger 5cm into the soil. If it's moist, don't water yet.

2. Underwatering

Dry, crispy yellow leaves (often from the tips) with bone-dry soil = underwatering. Less common than overwatering but still frequent. The fix: water thoroughly until it drains from the bottom, then establish a consistent watering schedule based on how quickly that particular plant and pot dry out.

3. Not enough light

Pale, washed-out yellow leaves — especially on lower or older foliage — can indicate the plant isn't getting enough light to produce chlorophyll. Move it closer to a window, ideally one with bright indirect light. Avoid dark corners for most foliage plants.

4. Nutrient deficiency

Yellowing between the veins (the veins stay green, the leaf tissue goes yellow) is a classic sign of magnesium or iron deficiency — common in plants that haven't been fed in months or are growing in depleted compost. Feed with a balanced liquid fertiliser during the growing season (spring–summer). For a quick fix, a diluted Epsom salt solution (1 tsp per litre of water) addresses magnesium deficiency.

5. Pests

Spider mites, fungus gnats, and mealybugs can all cause yellowing as they damage plant tissue or roots. Check the undersides of leaves for mites (tiny dots and webbing), the base of the plant and soil for fungus gnats, and leaf axils for mealybugs (white cottony deposits). Treat with neem oil, insecticidal soap, or a systemic treatment depending on the pest.

6. Root bound

When roots fill the pot completely, the plant struggles to absorb water and nutrients efficiently, causing yellowing. Check by sliding the plant out — if roots are circling the base densely or growing out of drainage holes, it's time to pot up one size.

7. Natural leaf drop

If only the lowest, oldest leaves are yellowing and the new growth looks healthy, this is simply the plant shedding old leaves to redirect energy. No action needed — just remove the yellow leaves cleanly.

Still stumped?

Post a photo in the Aiya's Garden forum with a description of your watering habits, light conditions, and soil type. Our community is brilliant at diagnosing plant problems — most questions get answered within a few hours. You can also post in the Plant ID & Help category for targeted advice.