Tomato Plant Problems
Common Problems with Growing Tomatoes and How to Fix Them
Although tomatoes are not very fussy plants, there are some issues you may experience when growing tomatoes. Here I will help you identify the common tomato plant problems and give you some tips on how to solve or avoid them.
3 main areas of problems with tomato plants
What are the issues tomato plants may have?
The three main areas of problems with growing tomatoes are:
- Issues caused by inappropriate conditions (including mistakes in tomato care)
- Pests
- Tomato plant diseases
Let’s start with those related to inappropriate growing conditions or wrong tomato care.
How to Identify Tomato Plant Problems and fix them
How do I know if my tomato plants have problems and what to do about it? Here is what to look at:
Most common tomato growing problems and their signs
- Tomato cracks
- Curled leaves
- Puffiness (hallow fruits)
- Yellow leaves
- Sunscald
- Deformed tomato fruits (catfacing)
- Wilting leaves
Tomato cracks
Why do tomato fruits crack?
Tomato cracks appear due to rapid changes in watering, especially when there is a lot of rain after a spell of dry weather. When this happens, thirsty tomatoes soak up a large amount of water very quickly, which leads to cracking.
How to prevent tomato cracking?
Although you can’t control the rain, you can make sure that your tomato plants have enough water during the dry periods. To prevent tomato fruit splitting, maintain even moisture levels by watering them consistently and mulching.
Curled leaves
Curled leaves, also called leaf roll, can be a sign of a transplant shock, too high temperatures or dryness. Sometimes curled leaves can also be caused by lack of phosphorus, herbicide drift (leaves rolling downwards in this case), pest infestation or a viral infection. The reasons are many, so think about what could have caused it in your case.
To prevent leaf rolling, maintain consistent moisture in the soil, provide phosphorus-rich fertilization and make sure that your plants are hardened enough before transplanting them to the garden.
Puffiness (hallow fruits)
What is tomato puffiness?
Tomato puffiness occurs when the fruit looks normal on the outside but has empty spaces inside. It occurs most often in early fruit.
What causes shallow tomatoes?
Tomato puffiness can be caused by too high or too low temperatures, too high nitrogen levels or poor pollination.
How to prevent tomato puffiness?
If you are growing tomatoes outside, you won’t be able to regulate the temperature. What you can do, however, is to ensure appropriate nitrogen-rich fertilization and support pollination. How can you support pollination? Tomatoes are self-fertile, meaning each flower can pollinate itself. To help them do that, you can encourage bees in your garden by planting flowers or you can shak the plants gently to help the pollen move on the flower.
Yellow leaves
What causes yellow leaves on tomatoes?
If the leaves on your tomato plants turn yellow, and it happens before the end of the season, it can be caused by a variety of reasons, some of the most common include:
- Either over-watering or under-watering
- Lack of nitrogen, potassium, or magnesium
- Diseases such as early blight, late blight, or septoria leaf spot, tobacco mosaic virus
- Pest infestation by aphids, whiteflies, or spider mites
- Hot and dry weather
- Some tomato varieties are naturally more prone to yellow leaves than others
How to prevent yellowing leaves on tomato plants?
To prevent leaves on your tomato plants from turning yellow try the following:
- Provide fertilization rich in nitrogen, potassium and magnesium
- Water consistently and avoid overdrying and overwatering
- Keep an eye on the pests
Sunscald
What is tomato sunscald?
In simple terms, tomato sunscald is a tomato sunburn. Tomato sunscald occurs when the fruit is exposed to direct sunlight and heat for a prolonged period of time. This causes the skin to turn pale and become sunburned.
How to prevent tomato sunscald?
To prevent tomato sunscald provide shade to the tomatoes. You can do it by hanging a cloth or netting over the plants or planting your tomatoes between trees.
Deformed tomato fruits (catfacing)
Carfacing is usually caused by insufficient pollination caused by low temperatures or temperature fluctuations during the flowering stage.
To prevent tomato catfacing, grow your tomatoes in a place with consistent temperatures or plant them out later in the season when temperatures are higher.
Wilting leaves
What causes tomato leaf wilting?
The most likely cause of tomato leaf wilting is insufficient watering. Other possible causes include fungal wilt diseases, tomato spotted wilt virus and walnut toxicity.
In hot and dry weather it is a natural plant’s reaction to wilt in order to reduce water loss. To avoid wilting caused by dryness, water your tomato plants regularly, mulch to prevent soil moisture loss and consider adding some shade to protect the plants.
Pest problems
The second area of issues with tomato plants is pest infestation. Tomato plants can be susceptible to a variety of pests that can cause damage to foliage, stems, and fruits. Some common pests that attack tomato plants include:
- Aphids
- Cutwarms
- tomato hornworms
- Whiteflies
- Spider mites
Aphids
Aphids are one of the most common pests which are present in our gardens. They are small insects and there are many types of aphids: winged or wingless, green, black, grey and yellow. They feed on the sap of the leaves, stems, and fruits of tomato plants. Aphids can cause yellowing, curling, and stunted growth of the leaves, and can also spread plant diseases.
To deal with aphids on tomato plants, try these methods:
- Encourage natural predators such as ladybugs, lacewings, and syrphid flies
- Grow companion plants that deter aphids: dill, chives, marigolds, nasturtiums, and basil
- Use organic pest control such as horticultural (potassium) soap, horticultural oil, rotenone dust (derris) or insecticidal soap
Cutworms
Cutworms are a larval stage of certain moth species, they feed on stems and leaves, often cutting seedlings’ stems off at the soil level. If uncontrolled, they can cause extensive damage to your tomato plants. To get rid of cutworms try these tricks:
- Create physical barriers around the base of the plants, such as cardboard collars, tin cans or plastic cups.
- Pick them by hand!
- Encourage natural predators such as birds, spiders and toads
Tomato hornworms
Tomato hornworms are large, green caterpillars that feed on the foliage and sometimes on the fruit of tomato plants. They can cause significant damage if left uncontrolled.
To deal with tomato hornworms try:
- Handpicking – this is the most effective way to get rid of them
- Allowing natural predators such as wasps, ladybugs, and birds
Spider mites
Spider mites are tiny, spider-like pests that spin webs underneath the leaves. They feed on the leaves, causing yellowing, browning, and stippling of the foliage. Spider mites are especially problematic in hot, dry weather, and they can reproduce quickly, making an infestation difficult to control.
If you notice spider mites on your tomato plants, consider encouraging to your garden natural predators such as ladybugs and lacewings. You can also use insecticidal soap or neem oil to control the infestation for natural pest control and to avoid using pesticides.
Diseases
The main types of tomato diseases include:
- Blight
- Blossom end rot
- Blossom drop
- Septoria leaf spot
- Tobacco mosaic virus
Tomato blight
What does tomato blight look like?
Tomato blight is a fungal disease that can affect both the leaves and fruit of tomato plants.
Early blight symptoms may appear as irregular brown or black spots with a yellow ring around them. These spots can grow larger and merge together, causing the leaves to turn yellow and eventually fall off.
Late blight symptoms include pale brown wilting leaves and water-soaked indented spots on the fruits.
How to deal with tomato blight?
Here are some tips:
- Practice crop rotation
Tomato blight can survive in the soil for several years, so it is important to rotate tomato plants to a different part of the garden each year. - Water the plants at the base of the plant, and avoid getting water on the leaves.
- Consider using fungicides.
If the disease is already present, you can try fungicides such as copper-based fungicides, or chlorothalonil. - Remove infected leaves
Remove the infected leaves to prevent the spread of the disease and don’t compost them.
Blossom end rot
What is tomato blossom end rot?
Blossom end rot, appears as a black or brown lesion on the blossom end (bottom) of the tomato fruit. The lesion usually starts small and can increase in size as the fruit matures, eventually causing the entire fruit to rot.
What causes tomato blossom end rot? Tomato blossom may be caused by various factors including a lack of calcium in the fruit, uneven or insufficient watering, high nitrogen levels, and soil with a low pH.
As there may be various reasons why blossom end rot appeared on your tomatoes, you may have to try different fixes. Those fixes include:
- Fertilize with calcium. You can use calcium-rich fertilizers; add lime or crushed egg shells to your soil and compost.
- Water evenly and regularly to maintain a consistent moisture level in the soil. Mulch around the plants to help retain moisture in the soil and keep it at a stable level.
- Maintain appropriate soil pH
The ideal pH for tomato plants is between 6.0 and 6.8. If you want to check your soil pH, you can use a soil pH test like this:
/>Blossom Drop
What is a tomato blossom drop?
Tomato blossom drop means that flowers on a tomato plant fall off before they form a fruit.
Tomato plants losing flowers may be caused by extreme temperature changes, lack of water, lack of nutrients or over-fertilization, pest infestation, various diseases or lack of pollination (the latter can happen when you are growing tomatoes indoors).
Here is what you can do to deal with blossom drop:
- Provide stable temperature and even watering
- Ensure appropriate fertilization
- Monitor for pests and diseases
- Manually pollinate the flowers or use fans for pollination
Septoria leaf spot
Septoria leaf spot is caused by the fungus Septoria lycopersici, which infects the leaves and spreads quickly in warm, wet conditions. Symptoms of Septoria leaf spot include small, circular, brown or black spots that appear on the leaves, often surrounded by a yellow halo. As the disease progresses, the spots will grow and eventually cause the leaves to wilt and drop from the plant.
Septoria leaf spot is difficult to control once it has infected a plant, but there are ways to prevent the disease from spreading. What you can do is:
- Avoid overhead watering to keep the plants dry
- Keep the proper spacing between plants
- Remove infected leaves and destroy them to prevent the spread of the disease
Tobacco mosaic virus
The tobacco mosaic virus is a highly contagious viral disease that affects tomatoes and other garden plants. It is transmitted mechanically (e.g. by insects or gardener’s hands) and can be very persistent.
What does the tobacco mosaic virus look like? On the infected plants, a green and yellow mosaic-like pattern appears, hence the name. Patterns of dead tissue can also develop on the fruit. Although the mosaic virus won’t kill your tomato plants, it will affect the crop.
To avoid the mosaic virus start growing tomatoes with healthy seeds, wash your hands after handling infected plants, sterilize all gardening tools, and don’t compost the infected plants or fruits (the virus can survive even 100 years!)
Above are the most common tomato diseases. If you want to know more about fungi, viruses and other diseases your tomato plants may suffer, you will find more information here:
- 25 tomato diseases and how to protect your plants
Summary
Being able to identify the problems with your tomato plants, and knowing how to prevent and fix them will help you grow beautiful high yielding tomatoes. I hope this helps you to troubleshoot the most common issues. If you want to know more or if you have other issues not covered here, check out these articles where you will find more in-depth information:
- Pests on tomato plants
- 25 tomato plant diseases
- What not to do when growing tomatoes
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