Tomato Plant Wilting (Drooping) Causes and What to Do About It
Tomato plants wilt and droop for a number of reasons—some indicate a serious problem caused by disease, while in other cases it's absolutely nothing to worry about. Almost always, you may notice a droopy tomato plant after you have just transplanted it. Give it a day or two and the problem should resolve itself. Another common reason for wilted leaves is a lack of water in the soil. Don't instinctively water whenever you notice wilted leaves though, because overwatering is also a cause.
It is often not a cause for worry, but there are instances where drooping leaves are the result of a pest attack or a disease. It is important that you can distinguish the different causes and address the problem. Resolving the problem quickly can help save your tomato plant and the plants around it.
This article will cover the main causes of wilting or drooping in tomato plants and provide guidance on what you can do to help your plants recover.
What Causes Wilted Tomato Leaves?
There are quite a few clues that help you solve the mystery behind the actual cause of your tomato plants wilting. Let's take a look at some of the common, and also rare causes and their associated symptoms:
Recently Transplanted Tomatoes
As mentioned in the introduction, many people find their recently transplanted tomato plants to be droopy after their first day out in the sun. This is caused due to sun-stress when you have not sufficiently hardened a tomato plant before placing it out under the direct sun. Hardening is basically the process of getting your plant used to the sun by placing the container out in the sun for a few hours each day prior to transplanting. Read my article on transplanting tomatoes for a detailed guide on the topic.
Another possibility would be because of root damage when you transplanted. If you did not use the entire root bundle, but instead dug up the plant from a growing container it is very likely that some of the secondary roots would have broken up. The reduced root system means there's less capture area for water to get into the plant system. This problem will fix itself in a few days, but you should notice the plant getting better day-to-day.
The other reason could be that you are watering the plant with the same amount of water as you did when it was indoors. It's very likely that the soil is drying out a lot quicker due to the heat of the sun and the outdoor environment. Your plant, therefore, does not have access to sufficient water.
Under-watering: If you notice a droop with thin, somewhat dry, and paperlike leaves it is very likely that the droop is caused due to the under-watering of the plant. To confirm, check the soil. If it is dry one to two inches (5 cm) below the surface, water the plant. Using your favorite kind of mulch will help retain moisture among other things.
This happens often if you are new to growing a particular variety or if you are planting in a new soil/environment. As long as this does not happen too often you should be fine and your tomato crop won't be harmed.
Over-watering: The inverse is also true wherein your plants droop if there's too much water in the soil. In this case, the leaves would be droopy but they are not dry or paperlike but are completely hydrated. To check if over-watering is the possible cause take a look at the soil. If it's wet to the touch even an inch or two below the surface, let it dry out and keep an eye on your plant.
Watering your tomatoes is the single most important task for a number of reasons. When you splash water onto the plant you could end up creating the perfect condition for a number of pathogens, inconsistent watering during the fruiting stage can cause ripening tomatoes to crack or blossom end rot. I have written a complete guide on watering tomatoes for those interested.
Other Environmental Causes
It is well known that growing tomatoes and some other plants near a black walnut tree or if your tomato plant was out during a frost event the leaves are going to wilt. In both circumstances, the plant may not grow very well and it is best to avoid these two scenarios.
Please note that over or under-watering can always seem like the cause of wilt and it often is. But, the soil is always going to seem dry or wet to the untrained eye. You should, therefore, continue reading to find out if your tomato plants are actually suffering from some sort of disease.
Wilt Caused by Pathogens
When people talk about wilt they are almost always referring to the symptom of a disease, either fungal, bacterial, or viral. It is very important that you identify whether your plant is wilting due to physiological conditions or a pathogen. If the problem is caused by a pathogen it is almost always best to uproot the plant and get rid of it to prevent the problem from spreading to your other plants.
Fusarium wilt is a soil-borne fungal infection which means that it enters the vascular system of the plant through the roots. It is present in regions with warm and moist weather. As the fungus spreads through the vascular system and grows, it clogs the system blocking the flow of water to entire sections of the plant at a time. This lack of water results in the symptoms of yellowing leaves, stunted growth, and wilting.
You would notice the lower leaves begin to turn yellow and very often just one side of the plant or certain lower branches are affected before it affects the entire plant causing the death of the plant. Destroy the infected plant and do not compost it as the fungus is capable of staying idle without a host for a few years. If your soil is prone to fusarium wilt you should opt for resistant plant varieties which are marked with an F following the name on your seed pack.
Very similar to fusarium wilt, verticillim wilt does not kill the plant but reduces growth and production. This fungus prefers cool moist environments.
Typically seen towards the mid or end of the growing season, the pathogen makes itself known by causing v-shaped yellow discolorations on the lower leaves before spreading throughout the leaves. The plants are often not droopy in the evenings when suffering from verticillium wilt.
Please note that a potassium deficiency shows up in a similar way (see image below) and some people have mixed up a potash deficiency as verticillium wilt. Remember that verticillium wilt begins from the lower leaves and you would notice that the leaf wilts which is not the case if it is a potassium deficiency.
Again, just like fusarium, this fungus also lives in the soil and can be dormant without a host for a few years. If you know that your region is prone to this disease it is best to buy varieties that have a resistance marked with the letter V.
I have never come across this problem as it is common in South Carolina, but for the sake of completeness, I am adding information based on research on this fungal infection.
During the early stages, it is difficult to differentiate between southern blight and verticillium wilt or fusarium wilt because the yellowing and the wilted leaves begin at the base of the plant.
During the later stages, the plant collapses. However, you can determine the fungus to be southern blight by looking for white hyphae or mycelia which show as stingy, mold-like substances near the base of the stem, on the roots, and the soil surrounding the plant. There is no way to treat an infected plant. The Beaufort county center suggests that you rotate solanaceous crops on a three-year rotation if your soil is infected.
Tomato Spotted Wilt Virus (TSWV)
The name suggests that the virus only affects tomato plants, but that's not true. Various species of plants can be infected across the globe. The virus is spread by different species of thrips which are tiny insects that feed on the sap of plants.
The symptoms differ depending on the stage of growth of the tomato plant. Unfortunately, this can happen at any time, even during the fruiting stage.
Unlike the other diseases we have seen up to this point, this virus affects the tips of the plant, that is the parts that are actively growing. When it affects fruit, unripe or ripening ring-shaped marks are seen.
The virus may cause just the tips of the plant to wilt or in extreme cases to die back. Leaves that do grow out on plants that are not too badly affected can turn brownish or bronze. They may even curl upwards. You should not mistake all upward curls with this virus though. Read my article on tomato yellow leaf curl for more on this.
It is very easy to misjudge yellowing and brown spots on your tomato leaves. If you are not quite sure whether you are suffering from TSWV or something else, you should take a look at my article on yellow leaves on tomatoes.
Unfortunately, there is no cure for the TSWV, but if your garden is prone to this problem there are pesticides that are pollinator safe which you can use. You would have to consult your local gardening organization for more information on what you can use. The good news is that this is not a soil-borne disease and you, therefore, can safely plant a new crop in the same spot the next year without having to worry about the virus affecting your new plants.
Bacterial Wilt and Canker
If you paid close attention you would notice that wilt was not the main symptom in the case of the fungal and viral infections described above. However, in the case of bacterial wilt, wilt is the predominant symptom wherein there is no discoloration of the leaves. The plant continues to stay green with the tips of the plant wilting far more than the base before the plant eventually dies.
Common in regions with hot and humid conditions as well as in soil with slightly elevated pH, the bacterium affects the plants through the vascular system just like the fusarium and verticillium wilt fungi. It can stay dormant in the soil for a few years, too.
A common way to determine whether your plant is infected with fusarium or verticillium wilt is to cut off the stem and look for brown regions of fungal growth. I did not mention this earlier because these fungi affect the base of the plant first and to do this you would have to kill the plant.
This is not the case with bacterial wilt where you can chop off upper branches and place them in a glass of water. If you notice a white substance draining from the stem, you can be sure that it is infected by the Ralsonia solanacearum bacteria.
Unfortunately, there is no cure and the bacteria can be dormant in the soil for years. The best thing to do is plant resistant varieties. Infected plants should be removed and destroyed.
Nematodes can be very damaging and they can spread around your garden and move into your neighbors garden or come in from theirs to yours easily. They are worm-like and feed on tomato roots.
They damage roots and cause knots and balls, thereby reducing or preventing the roots from taking up water and nutrients. This causes the plant to wilt during hot conditions while it can recover during the evenings provided the plant still has some healthy roots. There is no cure. Resistant varieties are marked by the letter N.
Overcoming Tomato Wilt
As described you can only recover a tomato plant from wilt if the cause is environmental. When the plant wilts because of a pathogen it is almost always necessary that you uproot and destroy the plant.
However, if you learn that your garden is susceptible to a certain kind of pathogen you can always buy resistant varieties marked by VFN. Most resistant varieties are hybrids and this scares people. You should know that hybrids are not genetically modified and you can without worry plant them in your garden. My article on hybrid vs heirloom tomatoes explains the difference between the two.
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.