Why are my plant's leaves turning yellow?

By Sophie Sparkes · Updated September 2026 · 6 min read

Yellow leaves (a condition called chlorosis) are your plant's way of waving a flag. The good news: there are really only seven common causes, and most are easy to fix once you know what to look for. Here's how to diagnose yours.

Short answer: most yellow leaves are overwatering. If the soil is wet and the yellowing started on the lower leaves, water less. If the soil is bone dry and the leaves are crisp as well as yellow, water more. Those two account for the majority of cases; the other five causes are below.

1. Overwatering (the most common culprit)

Soggy soil starves roots of oxygen, and they begin to rot, which shows up as yellowing leaves, often starting low on the plant. The leaves may feel soft, and the soil stays wet for days.

Fix: Let the soil dry out before watering again, make sure the pot has drainage holes, and empty any saucer of standing water. Only water when the top 2-3cm of soil is dry. See our watering guide for the finger test.

2. Underwatering

The opposite extreme also yellows leaves. Here the soil is bone dry, the pot feels light, and leaves may be crispy at the edges as well as yellow.

Fix: Give the plant a thorough soak until water runs from the base. If the compost has shrunk away from the pot, stand it in a basin of water for 20-30 minutes to rehydrate fully.

3. Too little (or too much) light

Plants not getting enough light often yellow and drop their lower leaves as they "give up" on the parts they can't sustain. Too much harsh direct sun, on the other hand, can bleach and scorch leaves pale yellow.

Fix: Move the plant to suit its needs: most houseplants love bright, indirect light. If a plant has been in a dark corner, shift it somewhere brighter gradually over a week.

4. Nutrient deficiency

If the soil is exhausted, plants run short of nutrients: most commonly nitrogen, which causes older leaves to yellow evenly. An iron deficiency, by contrast, yellows new leaves while their veins stay green.

Fix: Feed during the growing season with a balanced liquid fertiliser, and repot tired plants into fresh compost every year or two.

5. Pests

Sap-sucking pests like spider mites, aphids and whitefly drain plants and leave yellow stippling or patches. Check the undersides of leaves for tiny bugs, webbing or sticky residue.

Fix: Wipe leaves down, rinse with water, and treat with insecticidal soap or neem oil. Isolate the plant so pests don't spread.

6. Cold, draughts or shock

Sudden cold, a chilly windowsill, or a draught from a door can yellow leaves. So can the stress of being repotted or moved: plants dislike sudden change.

Fix: Keep plants away from cold glass and draughts, avoid temperatures they're not suited to, and give a newly moved plant a couple of weeks to settle before worrying.

7. It's just natural ageing

Not every yellow leaf is a problem. Plants naturally shed their oldest, lowest leaves as they grow. If it's just one or two at the bottom while the rest looks healthy, that's completely normal.

Fix: Simply remove the spent leaf and carry on.

Quick diagnosis cheat sheet

• Soft, yellow, soggy soil → overwatering
• Crispy, yellow, dry soil → underwatering
• Old lower leaves, even yellowing → nitrogen / natural ageing
• New leaves yellow, veins green → iron deficiency
• Speckled or patchy, bugs underneath → pests
• Pale, bleached patches in bright sun → too much light

Yellow leaf questions

Why are my plant's leaves turning yellow after repotting?

That is transplant shock, and it is normal. Roots get disturbed, the plant pauses, and it sheds a few leaves while it settles. Keep watering steady, keep it out of direct sun, and do not feed it: a stressed plant cannot use the fertiliser and it makes things worse. New growth within two or three weeks means it has recovered.

Why are my plant's leaves turning yellow at the bottom?

Usually one of two things. Plants naturally shed their oldest, lowest leaves as they grow, so one or two yellowing at the base while the rest looks healthy is completely normal. If it is spreading upwards and the leaves are evenly pale, that is a nitrogen shortage and the plant needs feeding or fresh compost.

Why are my plant's leaves turning yellow and drooping?

Check the soil before you do anything, because the two causes are opposites. Yellow and drooping with wet soil is overwatering and the start of root rot. Yellow and drooping with dry, light compost is simple thirst. Guessing wrong here is how people kill the plant they were trying to save.

Should I cut yellow leaves off?

If a leaf has gone fully yellow, remove it. It will not turn green again and the plant is no longer getting anything from it. If it is only part yellow, leave it alone for now: the plant is still drawing nutrients back out of it, and cutting early wastes them.

Do yellow leaves turn green again?

No. Once the chlorophyll has gone from that leaf it does not come back, so do not judge your fix by watching the yellow leaves. Judge it by the new growth: healthy new leaves mean you have fixed the cause.