Growing your own vegetable garden is satisfying and rewarding, but there are some challenges. Discovering dark spots on wilting leaves and blotches on tomato fruit is a sign of a possible disease, and infected plants often lead to the destruction of the entire crop. Learn what causes brown spots on tomato leaves and the proper steps to save your tomato garden.
There are thousands of tomato cultivars, from heirloom to hybrid, and a garden full of tomato plants with green leaves, flower blossoms, and shiny fruit is enough to make any gardener happy.
Unfortunately, these plants are susceptible to garden pests and diseases, and your vegetable garden is all but healthy. Tomato plants contend with a wide range of disorders, from blossom end rot and sunscald to septoria leaf spot and verticillium wilt.
Brown Spots on Tomatoes and Ways to Prevent Them
Tomatoes are nightshade vegetables, and they are one of the easiest plants to grow in the garden. Give them the right amount of sunshine and water, and they reward you with a tasty harvest at the finish of the growing season. Adding a bit of baking soda for tomato plants gives you sweeter fruits, too.
However, these plants are prone to pests and tomato diseases, and tomato leaves turning brown is one of the first signs that something isn’t right. What causes brown spots on tomatoes?
If left unchecked, the entire plant becomes unproductive, and these diseases spread throughout the garden. Therefore, knowing how to identify these problems is the first step to solving them.
There are many causes for tomato plant disease, and understanding the different bacterial and fungal diseases goes a long way to growing healthy tomato plants. We’ll discuss the causes of these disorders and ways to prevent them in the future.
Why are My Tomato Leaves Turning Brown?
Tomato leaves turning brown indicate that something isn’t right in the garden, and the cause ranges from improper watering and aphids to bacterial or fungal disease.
Unfortunately, these issues can also occur when growing tomatoes in a pot or bucket. It’s important to understand the culprit to determine the next course of action.
Both under-watering and overwatering cause the leaves to turn brown and curled leaves on tomato plants, as well as using too much fertilizer. If you’re sure that you provide your plants with the right amount of water and food, then there is probably a different issue to worry about.
Blights are a common fungal disease with tomatoes. Early blight survives through the winter on old vegetation and affects new plants by causing brown or black spots on leaves.
Late blight attacks older leaves and gives them a water-soaked appearance that later turns brown and papery. Alternaria leaf blight starts with small brown spots on the lower leaves near the base of the plant and progresses to a yellow halo.
A plant with yellow leaves or wilting is a sign of fusarium wilt, and yellowing between the major leaf veins indicates verticillium wilt. Neither disease is treatable, and it’s essential to remove and dispose of the entire plant.
Anthracnose is a fungus that attacks plants in the spring, causing lesions on the leaves. The fungi overwinter in twigs and plant debris, and the wet, cool conditions create the ideal environment for the fungal spores to spread.
What Causes Brown Spots on Tomatoes?
There are a variety of diseases that affect plants and cause spotting. Some disorders cause the leaves to develop gray, yellow, or black spots, while others affect the fruit. What causes brown spots on tomatoes, and how can you prevent them?
If you notice random bruises on the plant’s fruiting bodies, this is a sign of Anthracnose. This fungus rears its ugly head as the weather gets hot and humid, causing sunken spots on your otherwise healthy tomatoes.
It’s still safe to eat these fruits by cutting off the bruised section. What causes bottom rot on tomatoes? Blossom end rot is a very common problem with tomatoes. Brown, rotten looking circles on the bottom of the fruits are a sure sign, and there are a couple of reasons this happens.
A lack of calcium in the dirt and inconsistent watering are the two main causes and easy to rectify. Another tomato disorder is bacterial speck.
The symptoms are canker on the stems and small dark spots on the leaves and fruits. While the tomatoes are still safe to eat, they are not very attractive.
A final issue you come across with tomatoes is fruit with concentric rings or cracks. This is actually not a disease but rather the result of rapid changes in the soil moisture and temperatures, and your best option is to harvest them right away to prevent rotting.
Ways to Prevent Brown Spots on Tomato Leaves
Why are tomato plants turning brown, and can you save the affected plants? If the problem is insect-related, there is a good chance of saving some of your crops using a pesticide. However, a fungal disease requires a different remedy.
The most effective measure to take to grow the healthiest tomato plants is to purchase disease-resistant varieties, whether they are seeds or young plants from the nursery.
Planting cherry tomatoes or other varieties in a new garden bed is best if you struggled with a disease the previous year to reduce recontamination. Tomatoes have low watering needs, and giving them too much water promotes fungal growth.
Make sure to provide them with a drink in the morning when the top three inches of soil are dry, and use a soaker hose to keep the leaves from getting wet.
Apply fungicides, such as chlorothalonil, when necessary. Prune infected leaves and stems immediately and discard them in a location away from your garden.
Make it a routine to disinfect all your garden tools to keep from spreading disease from one plant to another.
Fungal spores overwinter and splatter easily on your plants during rainfall, so spread a decent layer of mulch throughout the garden bed to halt weed growth and promote a robust tomato plant.
Tomato plants grow quite dense, so prune them as they grow to promote good air circulation. Clip new sprouts from the main stems once they begin fruiting and train them into an open form.
Insects weaken plants, making them more vulnerable to disease, so use an insecticide as soon as you are aware of a bug problem. Feed your plants a couple of times during the growing season to keep them strong and healthy.
Crop rotation is another good practice since diseases are the result of a pathogen in the ground. Planting your crops in different locations each year reduces the number of soil pests and lessens the chance of tomato plant disease.
You put a great amount of time and effort into your garden, planting and nurturing your plants for a bountiful harvest.
Watching the tomato leaves turn brown and fall to the ground feels devastating. Understanding what to look for and how to stop it in advance is the best way to ensure your garden grows healthy and productive.
It’s vital to understand what is causing brown spots on tomato leaves to save your garden veggies and prevent future problems, so why not share our tomato plant disease guide with the gardeners in your life on Facebook and Pinterest?