My tomato plant has yellow leaves. Help! A tomato plant is fairly easy to grow, which is why many people grow them in their backyards or even in containers placed on their balconies. However, one common problem that tomato plant growers experience is their tomato leaves turning yellow.
There are many reasons why you’ll get yellow leaves on tomato plants. But whatever the cause or reason is, yellow leaves indicate that your plant is under stress.
It might be due to an environmental factor, a disease, or some other reason. In order to fix this issue, it is crucial to first discover the underlying issue.
So, to help you have healthy tomato plants in your grader, we have enlisted the most common reasons for yellow leaves in the tomato plant and their suitable solutions.
Keep reading to learn how you can keep your tomato plants green and healthy.
Key Takeaways
- Addressing Yellow Leaves: Focus on identifying and treating the causes of yellowing leaves, from nutrient imbalances to diseases, for healthier tomato plants.
- Essential Care Practices: Emphasize the importance of proper watering, sunlight, fertilization, and pest control in preventing common tomato plant issues.
- Environmental Awareness: Understand how temperature, sunlight, and water affect plants to adjust care and prevent stress-related yellowing.
- Regular Monitoring: Maintain ongoing observation and adjustment, including pruning and disease vigilance, for early problem detection and healthier plants.
Why Are Leaves on My Tomato Plant Turning Yellow?
Below are the possible causes of why leaves on your tomato plants are turning yellow.
Transplant Shock
Transplant shock is a temporary condition that occurs when plants have been transplanted from one place to another.
This type of shock commonly happens when tomato seedlings are transferred from a warm indoor environment to an outdoor ground or container in the early spring when nights still have low temperatures.
After one or two weeks of transplant, you will notice that vibrant green leaves that once looked fresh have now started turning pale yellow.
However, the newer leaves that will start growing at the top of the plant will still be green compared to the yellow leaves at the bottom of the plant.
Remember that it is completely normal and just a temporary period of transplant shock.
How to Fix It
One of the popular techniques that home gardeners use to fix this issue is applying one tablespoon of granulated sugar mixed in half gallon water. It is not a scientifically proven method, but people have still found it helpful.
You can prevent or reduce the symptoms of transplant shock by keeping your plant in the shade if the temperature is very high during the day and by giving it plenty of water every day.
It would help if you also hardened off your tomato seedlings before they are permanently transplanted into the garden.
To harden off tomato seedlings properly, you have to slowly expose seedlings to outdoor factors like sunlight, wind, temperature, etc. This way, they will adjust themselves according to the external environment even before being permanently transferred.
Lack of Water
One of the common causes of the yellow tomato plant leaves is the lack of water. If your plant does not get enough water, it will first start wilting then its leaves will start turning yellow.
Their edges will first turn yellow, and then the whole leaf will become yellow and drop off the tomato plant.
How to Fix It
You can treat this problem by watering the plant regularly. Try to water it every morning and, if possible, avoid making leaves wet.
Do not give excessive water instantly. Instead, give water slowly so that roots and soil can absorb it gradually. You can also use a water meter if you want to measure the moisture content of the soil.
Excessive Watering
Not only does lack of water make tomato leaves yellow, but excessive water can also do that.
Tomato plants are thirsty by nature, especially when it is the growing season. But that does not mean you can water them every time you look at them.
No, don’t do that because doing so can drown the plant and have a negative impact on its health.
When the soil has more water than its capacity to absorb it, it starts becoming soggy and fails to maintain the normal flow of air.
As a result, the plant does not get enough air that it needs to survive, so its leaves start turning yellow.
How to Fix It
You can fix such yellow tomato leaves in different ways.
First, remove the mulch layer if it has developed on soil near the base of the plant. Then, expose soil to sunlight so that water can evaporate and airflow gets normal again. If a plant has excessive leaves, then it is better to trim them as well.
You should water the tomato plant twice a week by keeping in mind the soil type and weather conditions.
If you like watering manually, use a water meter to measure how much water you give to the soil.
An automatic drip irrigation system is also very helpful in saving water yet giving enough water to the tomato plant roots.
Not Getting Enough Sunlight
Another reason that could cause tomato leaves to turn yellow is the lack of sunlight.
Even if you have grown a plant in an open space where it gets all the light, its bottom leaves may still not get enough sunlight because of the upper leaves.
As a result, they start turning yellow and then die.
Sometimes, the tomato plant also lets its lower leaves turn yellow so that they die, and growing tomatoes or the rest of the plant gets enough light to become healthy and reach maturity.
How to Fix It
It is a common problem that gardeners experience when they grow many plants in a small space. So, in order to avoid this issue, it is best to give each tomato plant enough room by growing fewer plants if you have a small space.
You should also keep an eye on weeds. Remove them whenever you see them so that your plants can get more sunlight.
Your growing tomato plant should get at least 8 hours of sunlight every day.
Some kinds of tomato plants like cherry tomatoes can survive even when they get 6 hours of sunlight. However, plants bearing large tomatoes should get 8 hours of sunlight.
Nutrient Deficiency
Nutrient deficiencies occur when your plant does not get a particular essential nutrient from the soil. It could be nitrogen deficiency, magnesium deficiency, or any other form of deficiency.
The most common nutrient deficiency is nitrogen deficiency. It occurs when your plant does not get much nitrogen. It affects only the older leaves while the upper leaves stay green.
Similarly, iron deficiency occurs when a tomato plant does not get enough iron from the soil. It first affects younger or newer leaves and then the leaf vines.
Such yellow leaves drop off after some time, and the entire plant becomes unproductive.
How to Fix It
The best way to solve nutrient deficiency immediately is by giving your plant light fertilizer or compost. They can be sprayed or added to the soil. You should always follow the manufacturer’s instructions to avoid burning the plant.
Fungal Diseases
Fungus tends to attack many plants every year and causes diseases and destruction.
One of the common fungal infections is the early blight that affects tomato plants. It results in the formation of yellow spots on leaves that later become brown spots and turn the whole leaf yellow.
Another fungal disease that develops in tomato leaves is the Septoria leaf spot caused by a kind of fungus residing in the soil. In it, yellowish circles start forming on the underside of leaves.
After some time, they cover the whole leaf and may also affect the plant stem. The affected yellow leaves start shedding, and the plant may stop fruit production and maturation.
How to Fix It
A plant affected by a fungal infection requires immediate action. You should first remove all the affected leaves then throw them in the leaves so that they do not spread infection.
After that, buy a suitable fungicide and spray it on the entire plant to kill fungus and prevent the further spread of the disease.
Bacterial Wilt
Tomato plants also develop bacterial diseases caused by different bacterial species.
Ralstonia Solanacearum bacterium is a bacterial species present in moist soil that causes bacterial wilt. The bacterium enters plants through the injured root system during plant transplantation. The disease does not show its signs until plants start getting ready for fruit production.
Entire leaves become yellow, and their shape also changes. Then, within a few days, the whole plant wilts and dies entirely.
Other types of wilting can occur due to fungal diseases, which include Fusarium wilt and Verticillium wilt. Fusarium wilt and Verticillium wilt can both be signs of a fatal disease that has taken over your plant.
How to Fix It
So far, no cure has been developed for this bacterial disease. Therefore, the best thing to prevent its spread is to remove the entire affected plant and dispose of it in a garbage container.
Make sure this infected plant does not come in contact with a healthy plant.
Should I Remove Yellow Leaves from The Tomato Plant?
A tomato plant can develop yellow leaves for various reasons. It is better to remove them because they will not turn green again.
Removing them will allow green leaves and the growing fruit to get more sunlight. Removing them will also help the plant save energy and sugar.
Tomato Plant Care
1. Proper Planting: Discuss the importance of choosing the right location with adequate sunlight (6-8 hours daily) and well-draining soil. Include tips on spacing plants to ensure good air circulation.
2. Watering Techniques: Emphasize the importance of deep, consistent watering while avoiding overhead sprinkling to keep leaves dry. Offer guidance on checking soil moisture and setting a watering schedule based on the climate.
3. Nutrient Management: Explain how to conduct soil tests and the significance of balanced fertilization. Highlight the essential nutrients like nitrogen, phosphorus, and potassium, and how to spot signs of deficiencies or excess.
4. Pruning and Support: Guide on how to prune for better air circulation and support plants with stakes or cages to keep them upright and healthy.
5. Monitoring and Adjusting: Stress the importance of regular check-ups for signs of stress or disease and adjusting care as the plant grows and seasons change.
Common Tomato Leaf Problems
1. Nutrient Deficiencies: Discuss how a lack of nutrients like nitrogen, potassium, or magnesium manifests in leaves. Include pictures for visual identification.
2. Pests and Diseases: List common pests (like aphids and whiteflies) and diseases (such as blight or leaf spot) that affect tomato leaves. Offer a brief description of each and how they damage the plant.
3. Environmental Stress: Describe how factors like too much or too little water, extreme temperatures, or improper sunlight can lead to leaf problems. Include how to recognize and differentiate these issues from diseases or pests.
4. Natural Aging: Explain that older leaves at the bottom can naturally yellow and die off as part of the plant’s growth cycle and shouldn’t always be a cause for concern.
Solutions for Yellowing Tomato Leaves
1. Addressing Water Issues: Provide a step-by-step guide to adjusting watering practices, including how to measure soil moisture and when to water based on weather conditions.
2. Nutrient Management: Offer solutions for nutrient deficiencies, such as how to amend the soil with the right type of fertilizer or organic matter. Include specific instructions for common deficiencies.
3. Disease and Pest Control: Recommend treatments for common diseases and pests, including organic and chemical options. Emphasize the importance of early detection and preventive practices.
4. Environmental Adjustments: Give tips on how to protect plants from extreme weather, adjust planting locations, or modify care throughout the seasons to prevent stress-induced yellowing.
5. Pruning and Maintenance: Instruct on how to properly prune affected leaves and maintain plant health to prevent future issues. Explain how removing yellow leaves can redirect energy to healthier parts of the plant.
By thoroughly covering these topics, you’ll provide readers with a comprehensive understanding of how to care for their tomato plants, diagnose common leaf problems, and implement effective solutions for yellowing leaves.
The Bottom Line
Yellowing leaves can be one of the many tomato plant problems you’ll have to overcome.
Yellowing leaves on tomato plants can be ugly and discouraging. Tomato plant leaves can turn yellow if they do not get enough water, lack sunlight, have a nutrient deficiency, or have developed a fungal or bacterial disease.
To get rid of this problem, you should first identify what is causing it then treat it by using the methods described above. The sooner you fix the yellow leaves issue, the better it is for your plant’s health.