The 6 Most Common Reasons Plants Turn Yellow

We often take pride when we see the results of our hard work in the garden: the rich green leaves fill our hearts with beauty and a sense of a job well done.



But when plants turn yellow, it is usually a sign of an underlying problem and that our plants need help.Here are the 6 most common reasons why that occurs and how to prevent it!

Plant aging & diseases

One of the reasons your plant’s leaves might be turning yellow can be due to the plant’s age. 

As some plants age, their lower leaves turn yellow and fall off. If this is the case, you shouldn’t worry about the plant’s health; it’s just a normal part of its growth. 

However, if you notice that the plant has become too leggy, you can consider trimming its main stem back to promote newer, more bushy growth.

Another culprit could be fungal, viral, or bacterial diseases.

The most frequent ones responsible for your plant’s leaves yellowing are:

  • Powdery mildew: a fungal infection that leaves white or grey powdery spots on your leaves, which leads to yellowing;
  • Leaf rot: a bacterial infection that causes brown or black spots;
  • Root rot: this fungal infection prevents the plant from absorbing water and nutrients, which then causes leaves to turn yellow.

In some cases, the damage may be so extensive that a complete garden clearance could be your only option. Sometimes getting rid of all affected plants and starting from the beginning is the best decision you can make for your garden. 

Moisture stress

Both overwatering and underwatering can cause a plant’s leaves to turn yellow.

When it comes to potted plants, it’s essential to know precisely how much water each species needs to grow healthy.

So if you notice that one of your plant’s leaves has become yellow, inspect the soil to find out whether it’s dry or soaked.

The soil can become waterlogged and drown the root system if the plant is overwatered.

Without enough oxygen, the roots will begin to rot, and the plant’s leaves will turn yellow.

To deal with this, quickly move the pot to a shadier area, even if your plant is sun-loving. Remove dying leaves and any dead or dying roots. Give your plant’s roots space to breathe by creating additional space around them.

Start watering the plant again once the soil has become somewhat dry to the touch.

Not giving your plants enough water can also cause them to shed leaves to conserve water. But before they start dropping, the leaves will usually turn a tinge of yellow.

Give it some water to save the plant, and start watering it more regularly. However, first, check online how much water your species of plant needs.

Light deficiency

When sun-loving plants don’t receive enough sunlight, their lower leaves often turn yellow before dropping. 


An easy way to find out whether lack of light is the reason for your plant’s leaves turning yellow is to check on which side the yellowing is occurring. 

Typically, the part of the plant farthest away from the light source will start turning yellow, while the leaves closer to the light will be green.

Solving this issue is simple, move the plant to a spot where it gets enough sunlight, or if that’s not a viable solution, opt for artificial plant light.

Lack of nutrients

Like all living things, plants need specific nourishment to grow and thrive.

And naturally, when these nutrients are lacking, that can cause the yellowing of the leaves.

The 5 most essential nutrients your plants need are:

  • Nitrogen: when deficient, older leaves yellow first;
  • Potassium: evident when leaf edges turn bright yellow;
  • Iron: responsible for chlorophyll production, and when deficient younger leaves turn yellow first;
  • Magnesium: deficiency manifests as yellow patches between leaf veins and older leaves;
  • Sulfur: becomes apparent when the newest leaves turn yellow throughout.


Since these deficiencies are responsible for most of the reasons why your plants turn yellow proper soil fertilization with the right plant nutrients is really important.

If you grow landscape plants and experience that problem, the soil’s pH can also be the problem. Since that index shows whether your greens can access nutrients, it can tell you whether the land is within the optimal range.

For example, most plants find soil with a neutral to a slightly acidic range of 6-7 pH ideal. However, some acid-loving plants also require an index of about 4.5-6.

A soil test can help you determine whether that’s the case but rest assured that the problem will persist until the proper soil amendments are applied to restore the pH balance. 

If the issue persists, you can talk to a gardening pro who will quickly assess the situation and offer the best remedies to restore your plants’ optimal health. 

Cold draft

If you’re looking after tropical plants, it’s essential to know that their leaves turn yellow and even drop when the temperatures drop. 

And worse yet, more prolonged exposure to intense cold can even cause browning of the foliage or pale transparent spots to pop up between the plant’s veins.

Here are a few things to bear in mind here:

  • During summer, keep your plant away from the air-conditioner; 
  • When winter comes along, move the plant to a warmer place: 
  • A great way to deal with tropical plants you’ll be overwintering is to increase their humidity through misting.


Another reason that plants turn yellow is because of various kinds of bugs that feed on them.

You can tell if that’s the case quite easily: there will often be visible signs on the leaves called “bullet” marks where the pest has fed.

The most frequent bugs who love to prey on your greens are aphids, scaly bugs, spider mites, whiteflies, and thrips.

Rest assured that most pest problems can be solved quite easily with a pesticide. 

However, instead of commercial products, try to go for natural ones like neem oil. Some plain dish detergent and water may also solve the problem.


So, there you have it, the top 6 reasons plants turn yellow.

Now that you know more about the reasons, you can efficiently deal with the causes and prevent that from occurring.

Happy gardening!