Why Are Your Onion Leaves Turning Yellow? (Solution)

Green onions, also called spring onions or scallions, are one of the most widely used vegetables in the kitchen. They are a plant species in the genus Allium. 

These plants taste milder than regular onions and are related to shallots, chives, leeks, Chinese onions, and garlic. Their leaves can be eaten raw or cooked and are available all year. 

They, like most plants, are susceptible to diseases that cause them to yellow. The phenomenon of yellow onion leaves can occur simultaneously, causing the onion plant to die in a short time.

Why are your onion leaves turning yellow? The causes include overwatering or underwatering, pests, and diseases. Let’s read this article for more information.

Why Are Your Onion Leaves Turning Yellow?

There are many causes of yellow onion leaves such as too much water or too little water, pests or insects that attack the roots, and so on. Let’s find out the causes and solutions below.

1. Onions Are Yellow Due To Overwatering Or underwatering

Green onion plants thrive in soil with consistent moisture, which means they should be watered properly and on a regular basis. If you notice the leaves turning yellow, this could indicate that you are overwatering or underwatering them. 

onion leaves turning yellow

To determine whether a watering problem is to blame, you need to use your hands to check the moisture and porosity of the soil.

If you believe the soil is too wet or too dry, poor watering techniques are most likely to blame for the yellowing leaves.

You should water the onion plants an inch of water each week to provide adequate water for the onion plants.

In addition, you should water in the morning and limit watering on onion leaves to avoid fungus growth in a humid environment.

If the weather rains continuously, you need to check the drainage of the soil. Too much water, sticky soil will also cause the onion plants to turn yellow at the same time.

If you water your onion plants too little, the onion leaves may turn yellow, but they can become fresh again when watered in time. The roots of onion plants are very shallow so they will quickly dry out if not watered adequately.

Read more: Is It Bad to Water Plants at Night?

2. Green Onions Are Yellow Due To Pests

Pests are one of the causes of onion leaves turning yellow or brown, and onions grow slowly, stunt, and die in a short time. Some common pests such as onion maggots or nematodes.

Onion maggots: Onion maggots are one of the most common pests of onion plants. When in the larval stage, they will attack the roots and bulbs, after they mature they burrow into the leaves and young shoots to destroy the onion plant.

In the early stages, the onion leaves may appear brown spots, and the leaves wilt and gradually turn yellow at the same time. You need early detection to remove infected onions and use biological pesticides to destroy them.

After harvesting onions, you need to clean the soil, rotate different crops, and only plant onions again when the temperature in the soil reaches 95 degrees F.

Nematodes: Nematodes are also common pests of onion plants. They cause onion leaves to turn yellow, brown, and severely deformed.

This worm is especially fond of tubers such as onions, chives, and garlic and wreaks havoc to a very rapid and dangerous degree. 

They attack onions from the ground making them unable to grow as well as causing onion plants to be damaged from the inside leading to serious consequences.

To get rid of these insects, you need to use insecticides as well as regular soil amendments to get rid of the nematode larvae in the soil.

Read more: Cut Onion Tops While Growing – The Truth Will Surprise You

3. Green Onions Are Yellow Due To Disease

Green onions can also be yellowed at the same time due to diseases. The disease can destroy a large area and directly affect the yield of the crop if not handled in time.

Green onion yellowing could also be caused by fungal diseases such as the following:

Pink root: Pink root disease is extremely common in onion plants and often causes their roots to become discolored. This disease is caused by a fungus in the soil and attacks the roots and onions directly.

This soil-borne fungal disease, which also affects garlic, attacks plant roots. Roots and bulbs become discolored, and the color of the leaves may also be affected. Leaf tips may appear wilted, and roots may turn pink, red, or purple. The disease will eventually stunt growth and result in low yields.

Pink root diseases will seriously affect the yield of the crop because they directly attack the roots and tubers of onions. As a result, the onion plant will suddenly wilt, and the onion will rot. 

To overcome this situation, you need to rotate crops as well as clean the soil regularly to remove fungi in the soil. Use a fungicide to kill it in time when you spot the early signs. 

Downy mildew: Downy mildew is also caused by the growth of a fungus that attacks onion plants. Signs of late blight are easy to recognize such as yellowing leaves, wilting, curled leaves, and plants dying slowly.

An early sign is yellow spots on the leaves which begins to spread very quickly from one onion plant to another. Onions are wet, watery, and rotten.

To overcome this situation, you need to control the moisture on the onion leaves by limiting watering on the onion leaves, and avoiding the use of drip or misting irrigation systems.

At the same time, you should check the drainage in the soil, and avoid the soil being too wet and sticky.

You also need to rotate crops and clean the soil to kill the fungus. In addition, when selecting onions or growing from bulbs, you need to make sure that the bulbs you choose are healthy and free of pests or fungal spores.

Bulb rot: Fungus is still the culprit causing this disease for onion plants. This fungus attacks onions directly and causes them to rot. Since then, the roots of the onion plant cannot transport water and nutrients, leading to the onion leaves turning yellow.

The initial signs such as wilted leaves, yellowing, the appearance of brown spots, and stunted and undeveloped onion plants. You can test an onion with your hand to feel its firmness.

When onion plants suffer from this disease, the yield will decrease rapidly if not handled in time.

To get rid of the fungus, you should keep the onion leaves dry and improve the soil regularly. Use biological products to remove fungal spores from the soil.


Green onions can become discolored due to a variety of factors. Green onions turning yellow could be caused by inefficient watering techniques, fungal diseases, or pests like onion maggots or nematodes. 

Pests and fungi develop mainly because the soil is too wet, and the leaves are constantly covered with water.

To limit the fungus, you need to limit wetting the leaves, improve the soil for good drainage, rotate the plants annually, and use biological products to kill the fungal spores.

In addition, join us for more useful tips in the process of growing onions to achieve the best yield. 

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