by Bethany Hayes
No one likes to discover their tomato plants wilting, and when you think everything is going well, it leaves you scratching your head. You wonder why are my tomato plants wilting, and the answer is – several things could be the root cause.
Tomato plants are picky about their situation, in particular, watering needs. Both over and under watering are frequent problems for tomato plants; finding the right balance can be tricky, especially for new gardeners. Depriving the roots of water or drowning them in water is equally bad.
Improper watering isn’t the only reason for tomato plants wilting. Let’s look at all the reasons why your tomato plants are wilting and if it’s possible to fix the problem.
6 Plus Reasons Why Your Tomato Plants Are Wilting
Recently Transplanted Seedlings
The first reason that might cause tomato wilting is if you recently transplanted your tomato plants, especially if the first day was sunny. Too much sun after transplanting into your garden beds causes sun-stress to plants that aren’t sufficiently hardened off before going out.
Root damage during transplanting might also cause wilting. Secondary roots break easily when transplanting tomato plants out of their seedling pots, and a smaller root-ball leads to less capture area for water to get into the plant.
Don’t worry; if root damage is the problem, you’ll notice an improvement within a week or two.
The most common reason why your tomato plants are wilting is due to either a lack of water or an abundance of water. Tomato plants need two inches of water per week, either through manual watering or rainfall. Providing over or under this amount for extended periods will lead to wilting.
How do you know if you’re over or underwatering? Here is what to consider.
Tomato plants need between one to two inches of water each week to stay sufficiently hydrated. During warmer weather, their water needs increase to the two inches mark.
The first thing you should do is to check the soil. If it’s dry one to two inches below the soil’s surface, it’s time to water.
Here’s what else you might notice if you aren’t providing enough watering.
- Thin, dry, paper-like leaves
Plants also wilt and droop if there is too much water in the soil. You can take a look at the ground to help you understand whether or not you’re overwatering. If the soil is wet to the touch an inch or two below the surface, it needs to dry out; watch the plant and wait for the ground to become dry below two inches below the surface.
Here’s what to look for when determining if you’re overwatering your tomato plants.
- Yellow leaves that start at the oldest leaves.
- Drooping leaves
- Leaves won’t feel dry or paperlike because they’re hydrated.
If your tomato plants are correctly waterly and start to wilt more after ensuring the appropriate amount of water is provided, your plants might have fungal wilt. There are three common types of wilting fungal diseases in tomato plants.
Verticillium Wilt Fungus
Verticillium wilt is a fungal disease that doesn’t usually kill a plant, but it does cause growth reduction and production. It thrives in cool, moist environments, appearing most often towards the middle or end of the growing season.
This fungal disease causes v-shaped yellow discolorations on the plant’s lower leaves before spreading throughout the leaves. If the leaves aren’t droopy in the evenings, chances are it’s not verticillium wilt.
Verticillium wilt lives in the soil and stays alive for years. If you discover your plants have this, it’s best to rotate crops to avoid planting tomatoes in the same area.
Fusarium Wilt Fungus
Fusarium Wilt is a soil-borne fungal disease that enters the vascular system of the plant through its roots. Like most fungi, Fusarium Wilt likes to spread in warm, moist, humid areas.
As this fungus spreads throughout the vascular system of your plant, it clogs the system, preventing the flower of water from reaching the rest of your plant.
Over time, this leads to symptoms like yellowing leaves, stunted growth, and wilting. In most situations, the lower leaves start to turn yellow, and often one side develops problems before the entire plant.
Unfortunately, destroying the infected plant is the only option. There are no treatments for this fungus.
At the start of this disease, it can be hard to distinguish from fusarium or verticillium wilt, but Southern Blight quickly shows its differences. This fungal wilt causes an appearance of white mold on the soil around the tomato plant’s base. It also might cause rapid wilting of the plant.
In the late stages, Southern Blight causes the entire plant to collapse.
As you can see, both of these wilting fungal diseases are similar. They cause the plant to wilt and die quickly because the fungus clogs the plant’s vascular system. The easiest to identify is Southern Blight, but that doesn’t mean it’s better to have that type.
The worse part of having tomato fungal wilt diseases is that they are all untreatable and nearly impossible to control. If you determine that your plants have this disease, it’s essential to remove them entirely from your garden and avoid planting any nightshade vegetables in the same soil for two to three years.
Tomato Spotted Wilt Virus
Are your tomato plants wilting and have purple or brown spots on the leaves? Chances are your tomato plants have a virus called Tomato Spotted Wilt Virus.
Unlike other viruses and diseases, Spotted Wilt affects the tips of the plants which are actively growing. It can affect fruit, causing ring-shaped marks to develop. It either causes the tips of the plant to wilt or die back in extreme cases.
Some other symptoms of Tomato Spotted Wilt Virus include:
- Leaves turning brown or bronze.
- Leaf curling
Tomato Spotted Wilt Virus’s problem is that there are no treatments, and removing the plants is a crucial step. The virus will spread to the other plants nearby if not removed.
Avoid planting tomatoes in the same spot for at least one to two years. It’s important to note that even though it’s named Tomato Spotted Wilt Virus, it doesn’t affect only tomato plants. Various plants experience this virus, spreading by different thrips species that feed on the plants’ sap.
Tomato Bacterial Wilt
While it’s less common, some tomato plants wilt due to Tomato Bacterial Wilt. It can be hard to identify this disease until the plants are dead because wilt is the only predominant symptom. You won’t notice discoloration of leaves or anything else. The plant continues to stay green even as the plant wilts until death.
Tomato Bacterial Wilt causes the plants to wilt and die quickly. After death, close inspection shows that the stem’s inside is dark, watery, and hollow.
Bacterial wilt is common in areas with hot, humid conditions, and it thrives in soil with a high pH range. Like other tomato problems, Bacterial Wilt affects the plant through the vascular system, and it lives in the ground for years.
There is no way to treat or fix Tomato Bacterial Wilt, and removing the plants is the only step possible. If you suspect that your plant has this bacteria, solarizing the garden bed can prevent it from spreading to future plants; the disease survives for years in the soil or weeds. It can be hard to get rid of this bacteria from a garden bed even if left unused for years.
Less Common Reasons for Tomato Plants Wilting
If you still suspect something else is wrong with your tomato plants, causing them to wilt, here are some of the less common reasons for tomato plants wilting.
Stalk borers are pests that attack a wide variety of plants, including tomatoes. The larvae dig into the stems and tunnel throughout them. The entrance hole is small and hard to locate, so discovering them that way is nearly impossible.
You can identify stalk borers if you find cream and purple striped caterpillars crawling on your plants.
Since treating stalk borers is challenging due to not noticing their presence until it’s too late, most affected plants wilt and die. The safest course of action is to pull out the plants and destroy them, which might kill the stalk borers as well.
While far from the most common pests, nematodes arguably are one of the most damaging tomato plants. Nematodes spread around your garden, naked to the eye under the surface, feeding on tomato roots.
As their name indicates, root-knot nematodes damage roots, causing knots and balls that make it impossible for the roots to take up water and nutrients throughout the plant. This causes the plant to wilt in hot conditions, but it might make a slight recovery in the evenings.
There is no cure or way to stop nematodes. By the time you realize there is a problem, the damage is done. If root-knot nematodes are common in your region, consider growing resistant varieties that are marked by the letter N.
Aphids are a common pest on tomato plants, and most infestations are minor, requiring little aid from you. These tiny pests like to suck out the sap from your plants as they spread a sticky substance over the leaves called honeydew.
That’s where the problem begins. Honeydew also attracts ants, which can cause a significant problem for your plants. It also attracts sooty mold that causes a black film to develop over your plants.
Like other pests, aphids damage your plants in vast quantities, leaving them vulnerable to bacteria, pests, and viruses that might cause even more severe damage.
Planting Near Allelopathic Plants
Certain plants are called allelopathic plants because they produce a substance that makes it harder for other plants to grow nearby. Typical examples are sunflowers, butternut trees, and black walnut trees.
The most common one is walnut toxicity because black walnut trees produce juglone, a toxic material that kills solanaceous crops, such as tomatoes, potatoes, peppers, and eggplant. Walnut toxicity causes:
- Stunted growth
- Yellowing leaves
- Wilting of foliage
- Death of the plants
Finding the Cause of Tomato Plants Wilting
The hardest part of dealing with your tomato plants wilting is figuring out what the cause is. Some reasons for tomato wilting are fixable, but many of the fungus, bacteria, and viruses that lead to wilting equal death to your plants. The most important thing you can do is to pay close attention and catch wilting as soon as it appears.