Yellow Leaves? It's Probably Not What You Think

The first time a leaf turned yellow on my monstera, I was convinced something was terribly wrong. I googled for hours. I adjusted the watering. I moved the plant. I bought fertilizer. I may have talked to it encouragingly.

The next week, another leaf turned yellow.

Panic.

More googling. Different theories. More adjustments. By the end of the month, I'd changed basically everything about how I was caring for this plant.

Then I learned something that would have saved me a lot of stress: sometimes leaves just turn yellow because they're old. It's normal. The plant is fine.

Not all yellow leaves are a crisis. But some are. Here's how to tell the difference.

When yellow leaves are totally normal

Plants don't keep their leaves forever. Older leaves, usually the ones at the bottom or back of the plant, eventually die off to make room for new growth. When they do, they turn yellow first.

This is completely normal and doesn't mean anything is wrong.

How to tell it's just aging: It's only one or two leaves at a time. The yellowing leaves are the oldest ones on the plant. The rest of the plant looks healthy. New growth is appearing normally.

If this describes your situation, just remove the yellow leaf (cut it close to the stem with clean scissors) and move on. There's nothing to fix.

When yellow leaves mean overwatering

This is the most common actual problem, and it's the one I ran into most often as a beginner.

When you water too much, roots can't get oxygen. They start to rot. Rotting roots can't absorb water properly, so ironically the plant shows signs of thirst (wilting, yellowing) even though it's sitting in soggy soil.

The pattern with overwatering is usually several leaves yellowing at once, or yellowing happening regularly over time despite the plant getting plenty of water. The leaves often feel soft and limp rather than crispy. The soil stays wet for a long time after watering.

If you check the soil and it's been wet for days, and your leaves are yellow and soft, overwatering is probably your problem.

The fix is straightforward: stop watering so often. Let the soil dry out before you water again. If the soil smells bad or you see fungus gnats, you might need to repot in fresh soil.

When yellow leaves mean underwatering

Less common in my experience, but it happens.

Underwatering yellowing usually starts with the lower leaves too (plants sacrifice old leaves first to conserve resources), but the difference is the leaves are dry and crispy, not soft and limp. The soil will be completely dry, sometimes pulling away from the edges of the pot.

The fix is simply to water more. If the soil has gotten very dry and hydrophobic (water runs right through without soaking in), try bottom watering: set the pot in a dish of water for 20-30 minutes and let it absorb from below.

When it's a light problem

Too much direct sun causes yellow or bleached patches on leaves, usually on the side facing the window. The leaves might look faded or washed out, sometimes with brown crispy spots.

Too little light causes a different pattern: gradual, overall yellowing. The plant looks pale and sad. Growth is slow or nonexistent. The plant might be stretching toward whatever light source is available.

If you've ruled out watering issues and the yellowing seems related to the plant's position, light might be the problem.

When it's nutrients

If you haven't fertilized in months (or ever), and the leaves are yellowing in a pattern (between the veins, for example, while the veins stay green), you might have a nutrient deficiency.

I'll be honest: I rarely have nutrient issues because I fertilize every few weeks during spring and summer. Most potting soils come with some nutrients, and light fertilizing keeps things topped up.

If you suspect a deficiency, start with a balanced fertilizer at half the recommended strength. Don't go overboard trying to fix it fast; overfertilizing can cause its own problems.

When it's pests

Check the undersides of leaves. Seriously, look closely. Many pests hide where you won't casually see them.

Spider mites leave tiny webs and cause stippled yellowing. Aphids cluster on new growth and can cause distorted, yellow leaves. Scale looks like small brown bumps on stems and leaves.

If you find pests, isolate the plant immediately (so they don't spread) and treat with neem oil or insecticidal soap. Check all your other plants too.

The diagnostic process I actually use

When I see yellow leaves now, I don't immediately panic. I run through a quick mental checklist:

Is it just one or two old leaves at the bottom of the plant? Probably normal aging. Remove them and move on.

Is the soil wet and has it been wet for a while? Probably overwatering. Let it dry out.

Is the soil bone dry and has the plant been neglected? Probably underwatering. Water thoroughly.

Is there a pattern related to light exposure (yellowing on one side, bleached patches)? Light issue. Adjust the position.

Are there bugs or webs when I check the undersides of leaves? Pests. Isolate and treat.

Has the plant been moved recently, exposed to a draft, or experienced a temperature change? Stress. Give it time to adjust.

None of the above and I haven't fertilized in months? Maybe nutrients. Try fertilizing.

This sounds like a lot, but most of the time it's one of the first three. Overwatering especially.

What tracking taught me

The most useful thing I've done for diagnosing yellow leaves is keeping track of my watering.

Before I started tracking, I had no idea how often I was actually watering. I thought I was watering "about once a week," but when I looked at the actual data, some plants were getting water every four or five days.

Now when a plant develops yellow leaves, I can look back at my care history. If I see I've been watering every five days and the soil is staying wet, the diagnosis is obvious. If I see I haven't watered in three weeks, that's probably the issue.

It takes the guesswork out of it.

I use Beflore for this because the logging is quick and it shows me a timeline view, but the important thing is having some record you can refer back to.

Removing yellow leaves

Once a leaf turns yellow, it's not coming back to green. The chlorophyll is gone. The plant is reabsorbing whatever nutrients it can before the leaf dies completely.

You can leave yellow leaves on the plant until they're fully dead and brown, or you can remove them once they're mostly yellow. Either way is fine. I usually remove them because it looks tidier and lets me see new problems more easily.

Cut close to the stem with clean scissors. Don't pull, which can damage healthy tissue.

When to actually worry

Most yellow leaves are minor issues or normal aging. But there are situations that warrant real concern:

If many leaves are yellowing at once and the problem is spreading quickly, something is genuinely wrong. Check roots for rot, check thoroughly for pests, and consider whether something major changed recently.

If new growth is yellow or distorted, that's more serious than old leaves dying off.

If yellowing is accompanied by a bad smell from the soil, root rot is probably advanced.

In these cases, more aggressive intervention might be needed, like unpotting to check the roots and removing rotted sections.

But for the typical "a couple leaves turned yellow" situation? Usually not a crisis. Check your watering, check for obvious issues, and don't overthink it.