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Seedlings Turning Yellow

Solving the Mystery: Why Are My Seedlings Turning Yellow?

Are you growing seedlings for your herb or vegetable garden or planning a flower bed from your seeds? At one time or another, you will ask why are my seedlings turning yellow, as this is a very common problem that almost all plant growers face. The most common causes of yellow seedlings are nitrogen deficiency or wet soil, causing root rot. We will discuss the factors that contribute to seedlings turning yellow and ways to fix these problems. 

The other problems that can make the seedlings yellow are compacted soil, damaged roots, disease or pest issue, nutrient deficiencies, and incorrect soil pH levels. By observing your seedlings and the conditions they are receiving, you can find out the cause for their yellowing and then move toward fixing it.

Why are my seedlings turning yellow?

Seedlings are like toddlers, who can fall ill by a very small change in the conditions around them. Similar to how you care for toddlers, you must care for the seedlings. The care needs of every individual specie must be fulfilled, the common reasons why are my seedlings turning yellow are:

  • The seedlings don’t need the cotyledons anymore
  • Sunlight issues
  • Watering issues
  • Fertilizing issues
  • Need to be repotted
  • Disease or pest problem

Let’s discuss these problems and know about ways to fix each of these issues.

1. The seedlings don’t need the cotyledons anymore

Cotyledons are the primary or the first leaves of a seedling when it sprouts. They are not true leaves because they help deliver nutrients to the plant by carrying out photosynthesis. These leaves are important for the seedlings till the roots don’t establish as much as to start absorbing nutrients and moisture from the soil. s important for the seedlings. 

But when the tree leaves emerge and grow big and healthy to carry out photosynthesis, the cotyledons naturally turn yellow and fall off. This is a natural process and you should not be worried about this.

why are my seedlings turning yellow

2. Lighting issues

Every plant has its own light needs and the answer to why are my seedlings turning yellow can be unsuitable lighting.

Lacking light

If your seedlings grow best in bright direct sunlight, then if you plant them under a shade or filtered light, they can turn yellow. Before growing the seedlings, know about their sunlight needs and what would be the best place to grow them. The seedlings may turn yellow if you are using artificial light sources rather than natural light. Choose the right-to-grow lamp that has light similar to that of the sun. 

Excessive sunlight

You should carefully know about the light needs of the seedlings. Some mature plants may need full sun, but their seedlings cannot grow well in similar conditions. Seedlings are fragile and have a few leaves for photosynthesis and an underdeveloped root ball. It is a good idea to protect the seedlings from direct sunlight by shading them during the afternoon. 

Excessive sunlight

3. Watering issues

Both overwatering and Underwatering can harm the seedlings, so always water them properly. 


This makes the soil soggy and can damage the roots of the seedlings that are left to stay in this water for a long. Only some plants may rarely like to sit in waterlogged soil, and for the rest of them, ensure that water drains well from the soil. 

The roots become rotten due to wet soil and it can be deadly, particularly in the case of seedlings.


Overwatering proves damaging for the roots and insufficient water can lead to killing the seedlings. The seedlings turn yellow due to the nutrients not reaching the roots to absorb them, resulting from dry soil. 

4. Fertilizing issues

Fertilizing issues

Both too much fertilizing and too little can lead to the seedlings turning yellow. The seedlings need some fertilizers to trigger new growth and make them strong enough to fight off diseases. You should understand the fertilizer needs of the plant you are growing.

Excessive fertilizing

It can cause root burn or the seedling getting stressed due to the shot it gets if showing fast growth. 

Lack of fertilizersWhen you are planning to transplant your seedlings, then lack of nutrients in the soil can prove a very destructive factor. The seedlings cannot grow new and healthy stems and leaves without getting their required share of nutrients. This leaves you wondering why are my seedlings turning yellow. Provide slow-release organic fertilizers and food supplements to your seedlings to support their growth.

5. Need to be repotted

why are my seedlings turning yellow

Some seedlings prefer to be planted or transplanted at a specific time. If you don’t do it on time, then it can make the seedling turn yellow and wilt. 

For instance, if the care needs of your seedling list moderate temperatures, then you should transplant it in early spring when the days warm up a bit or in the early fall. If you even delay the transplant for a few weeks, then the seedling is likely to show stunted growth due to excessive heat and this can cause it to turn yellow. 

In addition, if you plant your seedlings in a small container, they will run out of room quickly and use up their share of nutrients. Never postpone transplanting when it is time to do it. 

6. Pest and disease problems

The last problem we will discuss here for why are my seedlings turning yellow is the pest and disease problems. Discoloration of the roots and the plant can result from infections, such as root rot. You should treat the disease or pests in no time using fungicides. Immediate action and the correct measures can save the seedlings.

Is there a way to make the yellow leaves green?

You should first know how a leaf turns yellow: when the leaf no longer has its chlorophyll due to any factor, the plant abandons it and starts to extract leftover nutrients from this leaf. Now you may guess that once your seedlings turn yellow, you cannot normally make them green again. But it depends on the cause of the problem and how fast you detect and treat it. 

For yellow seedlings due to inadequate lighting, poor soil, and lack of watering, you may recover the yellow seedlings by providing them with the right light conditions, a dose of organic fertilizer, or regularly watering them respectively. 

But if there is a serious cause, such as damage to the roots, or a viral infection, you would have to start a new plant as the old seedling might die.

What are some ways to revive a seedling with yellow leaves?

You should first find out why are my seedlings turning yellow, then you can move towards fixing these yellow seedlings. As you now know that most issues causing yellow seedlings are related to the growing conditions. So, you can start by providing your seedlings with their ideal growing conditions as the first step.

why are my seedlings turning yellow

Some fixes that may help you are:

  • Amend the pH level of the soil: You should check the pH requirements of the plants you are growing and then check the soil pH reading, it should be within the suitable range. Most plants grow well in slightly acidic or neutral soil, but some may need alkaline soil to grow well. Therefore, fix the soil pH level by seeing what plant you are growing.
  • Provide enough sunlight: The seedlings should get adequate light to fulfill their growing needs. If you cannot expose them to sunlight, then use grow lights to make them grow well.
  • Water regularly: Always check how dry the top inch of soil feels before you water the seedlings. If it is wet and moist, then don’t water it till it feels a bit dry. Use well-draining soil and you should neither underwater nor overwater it.
  • Fertilize properly: If you are struggling with why are my seedlings turning yellow, then check the soil to determine which nutrients it is lacking. Use organic fertilizers and plant food supplements to enrich the soil and fulfill the fertilizer needs of your seedlings.

After solving the issue of seedlings turning yellow, you may stumble across the seedlings becoming leggy. Read more about the difference between healthy and leggy seedlings and ways to grow healthy and bushy seedlings here: Leggy vs healthy seedlings: what’s the difference?

Leggy vs healthy seedlings


Which minerals does a plant lack if its leaves turn yellow?

There are two common reasons for yellow foliage with deformities, pests of mineral deficiency. First, inspect the leaves for any pests and if you don’t see any, then it is a likely result of a mineral deficiency. The plant usually lacks boron or calcium, and a way to fix it is to fertilize the plant every month or take it out and plant it in fresh potting soil.

Is it good to trim away the yellow leaves of seedlings?

When you get an answer to why are my seedlings turning yellow, you may wonder whether you should cut off the yellow leaves or leave them. You should pluck away or trim the yellow or dead leaves as this keeps away unwanted pests from settling onto your plant. The nasty pests are usually attracted to dead or decaying leaves as compared to the healthy ones, and they usually infest the struggling plants. Trimming the yellow leaves would make the plant focus its energy on growing green and healthy leaves.

How much watering do seedlings need?

You must water the seedlings once every day or a couple of days, depending on where you put them and how much heat and sunlight they get. You don’t need to provide them a deep soak as larger plants need, because their roots are close to the surface and you are growing the seedlings in a small pot. Keep in mind that a possible answer to why are my seedlings turning yellow is overwatering them.

why are my seedlings turning yellow

Do I grow seedlings in direct sunlight?

You should first place your seedlings outdoors in a place sheltered from the wind and direct sun. You should increase the duration of sunlight exposure each day with 30-60 minutes of more filtered sunlight. First, give the plants direct morning sun and then expose them to noon-day sun in the end.

That’s a Wrap, but Before you go …

If you want to know why are my seedlings turning yellow, then you must know about the possible causes and then inspect your seedlings to determine what’s bothering them. The plausible reasons for yellowing seedlings are not the right light conditions, irregular watering, compact or poor soil quality, diseases, pests, etc. Carefully observe your seedlings as the first step and provide them with their required growing conditions. Then solve their problem by using a helpful measure to make them grow in strong and healthy plants.