8 Reasons Your Tomato Plants Are Dying (& How To Save Them)

Tomatoes are generally considered easy to grow at home, which is why they are so appealing to gardeners of all abilities and experience. Nevertheless, it's still possible to have problems with them. Fungal and bacterial diseases can quickly overtake these plants, and improper amounts of nutrients, water, and sun can also lead to havoc. Common signs there could be one of these problems include wilting or spotted leaves, lack of fruit, or loss of foliage.

Unfortunately, some tomato plant problems cannot be fixed, such as in the case of tomato spotted wilt virus. In other instances though, it may be possible to address tomato plant issues before it's too late — but you'll first need to determine the exact issue going on with your tomato plant. Once you know, you can take steps to save the plant or others surrounding it, and also help prevent similar issues from developing again in the future.

Tomato plants are unfortunately susceptible to numerous fungal diseases. All of them can cause visible damage, but in slightly different ways. For example, large black spots on ripened fruit may indicate anthracnose fruit rot, while early blight in tomatoes can cause darkened rings on both the fruit and the leaves. Withering leaves, fuzzy growths, and brownish-black spots on leaves and fruit may all indicate late blight. Septoria leaf spot affects stems and leaves only, quickly causing dark spots and complete loss of foliation. Buckeye rot is another possible tomato fungal disease, which affects the fruit only. With this disease, you may notice fruit that first develops brownish-black colored spots and then a white fuzzy growth on top. 

The key to fungal disease management in tomato plants is to recognize the signs of a problem before the entire plant succumbs to disease. Commercial or homemade fungicides for tomatoes can help treat fungal diseases and possibly prevent further spread. In some cases, the best course of action is to remove the diseased plant in order to save others nearby. Further prevention can involve removing plant debris, adding mulch, and making sure tomato plant foliage is kept dry by watering the soil only. 

Tomato plants are generally hardy and can do well in warm temperatures. However, they still need water to grow and thrive. If you're seeing curled leaves that are still green in color, and not any spots or fuzz that could indicate fungal disease, your tomato plant could just be lacking in water. Another sign is a lack of fruit from the plants. 

A lack of water can be dangerous for tomato plants in the long-term, but the good news is they may perk back up immediately after you give them water if you catch this problem early on. Be sure to water directly around the soil only so you don't inadvertently contribute to fungal disease development along the leaves, stems, or fruit. As a rule of thumb, tomato plants require about an inch of water every week, but sometimes more in hot and dry conditions. You can give these plants more water if you see some of the key signs above, or you can consider buying a moisture meter that can tell you when the soil is too dry. 

Just as it's important to make sure your tomato plants are getting adequate water, it's equally critical to ensure you're not overdoing it. This is a common mistake gardeners make after first transplanting tomato plants into the ground. While new tomato plants need daily watering, this is usually required for the first week only. A tomato plant with too much water won't be able to develop strong roots. On top of this, excessive moisture can promote fungal and bacterial diseases in your plants. As such, an overwatered tomato plant may exhibit wilting leaves, cracked fruit, or spots on its foliage. 

Scaling back on the amount of water can help save a tomato plant that has been overwatered. When it's time to water tomato plants, be sure to do so in the morning. This helps to ensure that any excess moisture evaporates during the day, and can mitigate diseases in your tomato plants. Again, it's also important to water at the base of the plants only.

Fertilizers are important tools to provide plants with the nutrients they need to grow and produce more fruit. Whether you've selected a synthetic or organic fertilizer, it's possible to overdo it. In particular, tomato plants are sensitive to excessive amounts of nitrogen. Wilting leaves are some of the first signs of this problem. Additionally, the leaves may curl, turn brown, or look like they have been burnt. Over-fertilizing can be problematic in tomato plants of any age, but especially if they are more mature. In these cases, the plant may look healthy, but it's not producing any fruit. 

If you're noticing possible signs of over-fertilization in your tomato plants, it's time to cut back on the amount of product you're using. You should also test the soil to confirm whether your plants are getting too much food. The ideal soil pH level for tomatoes ranges between 6.2 and 6.8. As a preventive measure, consider holding off on fertilizer for newly transplanted tomato plants until their roots take hold. 

If you have a garden and live in a subtropical or tropical region, it's important to be on the lookout for bacterial wilt. It's caused by the infamous Ralstonia solanacearum bacterium, and can be quite destructive. Tomato plants are most susceptible to this bacterial disease in climates with hot temperatures and high humidity. However, it can also sometimes cause problems in temperate climates, too. Among some of the possible signs of bacterial wilt in tomato plants include predominantly daytime wilting of leaves and stems, ooze-filled stems, and stunted growth. It's also possible for infected tomato plants to be asymptomatic. 

Any suspected bacterial wilt in tomato plants must be addressed right away to prevent further spread of the disease. This may unfortunately involve removing infected plants to help save healthy ones. Bacterial wilt can also survive in soil, so it is important to plant any new tomatoes in a new site entirely. Consider rotating with plants that are not susceptible to bacterial wilt for at least three years before planting tomatoes and other plants of the potato family in the infected site. Possible replacements include cabbage and beans. 

Plants can succumb to heat, especially when they aren't watered enough. On the contrary, if you're providing your tomato plants with plenty of water and they are in the shade, chances are that direct sunlight is not the issue here. In fact, tomato plants grow best in full sun. This is similar to other plants in the same family, such as peppers. Tomato plants that are placed in the shade are unlikely to thrive because they are not getting enough sunlight. Even if the tomato plant isn't dying, it will likely be less productive than it could. 

As a rule of thumb, tomato plants need at least six hours of direct sunlight every day. It's even better if they can get eight hours of sun or more. Before transplanting young tomato plants into the ground, it's important to be certain they will get their sunlight needs met, so you will need to plan ahead to be certain. Gardens that face towards the south will likely receive the most amount of sunlight throughout the day. 

If you're witnessing sudden wilting of your tomato plants without any obvious cause, stalk borers are possible. These small pests are gray colored moths as adults, but are problematic caterpillars in their earlier stages. If you do happen to see a stalk borer, you can identify it with its telltale purple and white stripes. They tend to crawl around tall grasses, but once they have found a plant in a garden, the caterpillars bore small holes in its stems and create destructive tunnels throughout the stalk. In addition to grasses and weeds, stalk borers infamously like to hang out in tomato plants.

Unfortunately, stalk borers are among some of the most difficult tomato plant issues to deal with. Some gardeners are successful in saving their affected tomato plants when opening the affected stems and removing the borers by hand, but these can be difficult to locate. Thinking of insecticides? No luck, they're immune. If any of your tomato plants do succumb to a stalk borer infestation, you may have to pull them out of the ground and start over. You may be able to help discourage future stalk borer infestations by making it more challenging for the pests to access your plants from the ground. This can involve keeping weeds and grasses at bay with mulching or mowing surrounding areas.

Staking is used by tomato growers to support large plants and optimize fruit production. This method isn't exclusive to tomato farmers, though. If you're growing tomato plants specifically for their fruit to enjoy at home, you may want to consider stakes. The larger a tomato plant gets, the heavier it ultimately becomes. While good in theory, the plant can sometimes collapse under its own weight as it starts bearing fruit. If you're starting to notice your tomato plants are collapsing, consider staking to help support them. 

To stake a tomato plant, place a piece of wood or bamboo rod into the soil away from the roots. Then, carefully affix the plant to the stake with a small amount of twine. This will encourage the plant to creep upwards along the stake, rather than collapse forward towards the ground. When staking tomato plants, it's also important to choose supports based on variety. For example, heirloom tomatoes may require larger stakes up to eight feet tall since they are larger plants. Multiple rows of tomato plants should also have at least four feet of space between them.