Plant symptoms · explained
Why are my plant's leaves turning yellow?
There are six usual reasons — and the pattern of the yellowing tells you which. Here's how to read it, so you fix the cause, not just the leaf.
Show a photo — get a free diagnosis →Yellow leaves are a symptom, not a diagnosis — and the two most common causes, too much and too little water, look similar but need opposite fixes. Treating the wrong one wastes days you may not have. So start by reading the plant, not by reaching for fertiliser or the watering can.
The 6 most common causes
1. Overwatering (the most common cause)
If the lower, older leaves yellow first, the soil stays wet for days and the base of the stem feels soft, the roots are likely drowning. Waterlogged roots can't take up oxygen — or nutrients — so the plant yellows despite plenty of water. Let the soil dry out, check drainage, and don't water on a fixed schedule — water when the soil is actually dry.
2. Underwatering
The opposite look: leaves go dull, then crispy and dry at the edges, and the whole plant wilts and perks up after a drink. The soil is bone-dry and may have pulled away from the pot's sides. Water thoroughly until it runs from the drainage holes, and consider a bigger pot if it dries out within a day.
3. A nutrient shortage
Pattern is the clue. Yellowing that starts on the OLD lower leaves while the plant keeps growing usually means nitrogen. Yellow NEW leaves with the veins staying green points to iron or manganese, often because the soil is too alkaline or too wet to release them. Feed appropriately — but rule out overwatering first, because soggy roots mimic a deficiency.
4. Too little or too much light
Not enough light makes a plant shed its lower leaves to save energy; harsh direct sun can bleach and yellow leaves in pale, dry patches. Move the plant to match what the species actually wants and give it a week or two to settle.
5. Natural ageing
A few of the oldest, lowest leaves yellowing and dropping while the rest of the plant looks healthy is completely normal — the plant is retiring old foliage. Nothing to fix.
6. Pests or disease
Look closely: fine webbing (spider mites), sticky residue or tiny insects (aphids, whitefly, scale), or defined spots and blotches (a fungal or bacterial disease) all cause yellowing. This is the one case where a precise identification really matters, because the treatment is specific to the culprit.
How to tell which one it is
Read three things and it usually narrows down fast: which leaves (old and low, or new and top), the soil (wet or dry a few centimetres down), and the leaf surface (clean, or spots, webbing or insects). If you see spots or pests, or it's still unclear, that's exactly what a photo diagnosis is for — it names the specific cause and the fix.
Diagnose my plant — free →Questions people ask
Can yellow leaves turn green again?
Usually not. Once a leaf has yellowed it rarely re-greens, because the plant has already withdrawn chlorophyll from it. The goal isn't to save that leaf — it's to fix the underlying cause so the NEW growth comes in healthy and green. The exception is a nutrient deficiency caught early, where feeding can partly restore colour to leaves that aren't too far gone.
Should I remove yellow leaves?
You can remove a leaf that is more than about half yellow or fully limp — it won't recover and cutting it lets the plant put energy into healthy growth. Use clean scissors and cut at the base. Leave leaves that are only slightly yellow if the plant is short on foliage, as they still photosynthesise a little. Removing leaves treats the symptom, not the cause, so always work out why it's happening too.
Why is my plant getting yellow leaves even though I water it?
Most often it's too MUCH water, not too little. Frequent watering keeps the roots waterlogged, they can't breathe or take up nutrients, and the plant yellows exactly as if it were starving. Check the soil a few centimetres down: if it's still damp, hold off watering, improve drainage, and let it dry out. If the soil is dry and the plant still yellows, look at feeding, light and pests next.
What does the plant lack when leaves turn yellow?
It depends on the pattern. Whole older leaves yellowing usually points to nitrogen; yellow new leaves with green veins point to iron or manganese; yellow with dark spots suggests disease rather than a deficiency. But a shortage of nutrients is often not the real problem — overwatered roots simply can't absorb the nutrients that are already in the soil, which looks identical. Diagnose the cause before reaching for fertiliser.
How do I know exactly which cause it is?
Read three things: which leaves (old and low, or new and top), the soil (wet or dry), and the leaf surface (clean, or spots/webbing/insects). Those three narrow it down fast. If it's still unclear — or if you see spots, pests or damage and want the exact culprit named — a photo diagnosis will identify it and tell you the specific fix.
Not just yellowing? How to save a dying plant · browse the disease library.