Yellow leaves are one of the most common houseplant worries. Sometimes they are completely normal, and sometimes they are an early warning. The pattern of yellowing usually points to the cause, so look closely before you change anything.
1. Overwatering
This is the most common cause. Roots sitting in wet soil cannot get oxygen, start to rot and stop taking up nutrients.
Signs: yellow, soft lower leaves, soil that stays wet for days, sometimes a musty smell or fungus gnats.
Fix: let the soil dry out more between waterings, make sure the pot has drainage holes, and empty saucers after watering. If roots are brown and mushy, trim the rotten parts and repot in fresh, well-draining mix.
2. Underwatering
Signs: yellow leaves that turn crispy and brown, drooping, very dry soil pulling away from the pot.
Fix: water thoroughly until it drains from the bottom. If the soil has become hard and water runs straight through, soak the pot in a bowl of water for 20 to 30 minutes.
3. Natural ageing
It is normal for a plant to lose an occasional old leaf at the bottom as it puts energy into new growth. If only one or two lower leaves yellow now and then while new growth looks healthy, there is nothing to worry about.
4. Not enough light
Signs: pale, yellowing leaves, slow growth, long stretched stems leaning toward the window.
Fix: move the plant closer to a window with bright, indirect light, or add a grow light during darker months.
5. Too much direct sun
Signs: yellow or bleached patches on the leaves facing the window, sometimes with brown, crispy spots.
Fix: move the plant back from the glass or filter the light with a sheer curtain.
6. Nutrient deficiency
Plants in the same soil for a long time can run low on nutrients.
- Nitrogen deficiency: older, lower leaves yellow evenly first.
- Iron or magnesium deficiency: yellowing between the veins while the veins stay green, often on newer leaves.
Fix: feed with a balanced houseplant fertiliser during the growing season, following the label. Repot every year or two in fresh mix.
7. Temperature stress and draughts
Signs: sudden yellowing or leaf drop after a cold spell, or near radiators, heaters, air conditioners or draughty doors.
Fix: keep most tropical houseplants between about 16 and 27 degrees Celsius and away from heat sources and cold draughts.
Bonus: pests
Spider mites, thrips and mealybugs feed on plant sap and can cause speckled yellowing. Check the undersides of leaves for tiny dots, webbing or white cottony patches. Wipe leaves, isolate the plant and treat with insecticidal soap if needed.
Should you remove yellow leaves?
Yes. A fully yellow leaf will not turn green again. Remove it with clean scissors or gently pull it away once it detaches easily. This keeps the plant tidy and lets it focus on healthy growth.
Quick checklist
- Check the soil moisture first.
- Look at which leaves are yellowing: old or new, all over or in patches.
- Consider recent changes in location, season or watering.
- Inspect for pests.
- Change one thing at a time and give the plant a few weeks to respond.
Quick answers
Should I cut off yellow leaves? Yes, once a leaf is mostly yellow it will not turn green again. Removing it with clean scissors keeps the plant tidy and lets it focus energy on healthy growth.
Is it normal for old leaves to yellow? A single lower leaf yellowing now and then is usually natural ageing. Many leaves at once, new leaves yellowing or yellowing with spots are signs to investigate.
How do I know if it is overwatering or underwatering? Check the soil a few centimetres down. Soggy soil, a musty smell and soft stems point to overwatering. Bone-dry soil that pulls away from the pot edge suggests underwatering.
Can tap water cause yellow leaves? Some sensitive plants react to salts or chlorine in tap water, often with brown tips rather than full yellowing. Letting water stand overnight or using filtered water can help those species.
When should I fertilise? Feed only during active growth, usually spring and summer, and follow the label. Too much fertiliser can burn roots and cause yellowing too.
