How to Treat Leaf Spot Diseases: Reasons + 11 Quick Fixes

Are you a garden enthusiast looking for ways to treat leaf spots? Read here to learn how to treat leaf spot disease for garden plants, houseplants, and your lawn.

If you are an avid gardener, you must have come across brown or yellowish spots on your plants. Are these signs of Overwatering or Underwatering?

Of course, seeing these leaf spots appear on your healthy plants can be frustrating. Hence, in order to ensure it doesn’t spread to other plants, you must treat them quickly.

The most common question from beginner gardeners is how to treat leaf spot disease. Since these spots are contagious, they can sometimes give new gardeners a pretty hard time.

Leaf spots appear when plants are infected by fungi. The fungus eats away at the leaves and causes holes to appear on the leaves. It can be treated in various different ways, such as removing the affected leaves, covering the soil, or using fungicides. Since the leaf spot disease is contagious, it is essential to treat it quickly before it spreads to other surrounding plants.

Continue reading to learn more about leaf spot disease and how you can treat them for different plants.

  • What is Leaf Spot Disease?
  • How to Treat Leaf Spot Disease on Tomatoes?
  • How to Treat Leaf Spot Disease on Houseplants?
  • How to Treat Leaf Spot Disease on the lawn?

What is Leaf Spot Disease?

How to Treat Leaf Spot Diseases
How to Treat Leaf Spot Diseases

Leaf spot disease occurs when fungi attack the plants, and brown spots appear on the leaves.

This progresses to small holes in the leaf, and a reddish brown halo surrounds them. Leaf spots can appear on house plants and outdoor plants alike.

If you do not control leaf spot disease, it is likely to spread to nearby plants and severely affect their health.

Airborne fungal spores are attracted to warm and wet surfaces on the leaves. Once the spores find a place to settle on the leaves, the fungus grows by reproducing, resulting in brown spots on the leaf.

The spot begins to spread out until it touches another spot on the leaves. The fungus grows until it consumes the whole leaf and turns it brown, and the leaf eventually falls off its stem

See also  21 Genius Ways to Use Plant Hangers for Maximum Wow!

The fungal spores are not gone when the leaf falls. In fact, they wait to find and occupy another warm and wet surface.

How to Treat Leaf Spot Disease on Tomatoes?

Leaf spots can appear on any type of plant. It often develops on garden tomatoes during the winter and initially spreads to the lower leaves.

Hence, if your garden tomato plant is affected by fungal spores, you will notice the lower leaves that are closer to the ground turn brown first.

The spots will be brown or black. Following are some tips to treat leaf spot disease on garden tomatoes:

How to Treat Leaf Spot Disease on Tomatoes?
Leaf Spot Disease On Tomatoes
  1. You can pinch off the leaf spots from the infected leaves and bury them in the soil.
  2. If you spot leaf spots on the lower parts of the plants, it is adequate to remove 1/3 of the leaves. However, it is essential to be careful and not remove more than this.
  3. It is essential to try and keep the leaves dry to prevent the tomatoes from getting leaf spot disease.
  4. In order to prevent the disease from spreading, some gardeners like to remove lower leaves from other plants as well to ensure they don’t catch fungal spores in the soil.
  5. This also helps enhance the air circulation for the plant, and the leaves dry faster.
  6. Tomatoes are highly sensitive to numerous herbicides, which is why it is better to try alternative treatments.
  7. You can also try covering the soil with plastic mulch, straw, or dried leaves. This will help prevent the disease from spreading to the tomatoes.

It is crucial for you to know that each spot has hundreds of fungal spores residing on it, and since they are contagious, they can spread to other plants in the surrounding area.

Hence, it is necessary for you to deal with the disease quickly and efficiently.

How to Treat Leaf Spot Disease on Houseplants?

Despite being inside, houseplants can also catch the leaf spot disease.

Your houseplants can attract bacteria and fungi if the potting mix has prevalent conditions for them to thrive.

You see, when the plant’s foliage remains wet for a long time and is surrounded by a cool environment, the fungi find itself an environment where it can grow.

Similar to garden plants, houseplants also display the same symptoms with brown, yellow, black, or reddish spots on the leaves.

See also  overwatering vs underwatering plants: 11 Early signs + Fixes

Here is how you can treat leaf spot disease in houseplants:

  1. The moment you see a leaf spot appear, remove the affected leaves.
  1. You must also remove the fallen debris on the soil because this is where bacteria thrive.
  1. In case the infection is severe and starting to spread to other plants, you can use a fungicide for the particular plant.

Here are a few actions you can take in the future to prevent leaf spot disease:

  1. Try to water the plants during the daytime so they are dry by nightfall.
  1. Try keeping the plant in a dry environment.
  1. If a plant has been infected, do not reuse its potting mix.

How to Treat Leaf Spot Disease in Lawn?

The grass on your lawn is no more safe from leaf spot disease than garden plants or houseplants. Bluegrass and Bermudagrass are the most affected.

Black or brown spots appear on the grass blades if it gets affected by leaf spot disease. They spread and widen and destroy the grass blades above roots.

This is known as the “melting out” phase.

Bluegrass and Bermudagrass are affected during different weather. Bluegrass gets affected in hot and humid weather, while Bermudagrass is likely to get leaf spot disease in cool and damp weather.

How to Treat Leaf Spot Disease in Lawn?
How to Treat Leaf Spot Disease in Lawn?

At times, these symptoms are confused with insect damage or drought.

The problem is that both require opposite solutions. Leaf spot requires less to no use of water, while damage from drought needs to be dealt with by watering the lawn.

Furthermore, you must note that leaf grass does not follow any pattern and will appear in the grass in random places. Following are a few ways to treat leaf spot disease in lawns:

  1. You can use nitrogen on the affected area in your lawn to eliminate the disease.
  2. Reduce the amount of water you use to water the grass.
  3. It would help if you also aerated the soil to improve the drainage of water.
  4. You can also apply fungicide to the affected area, but only when the spots first appear and the disease is in its initial phases.
  5. To prevent leaf spots in Bermuda grass, you can apply fungicide at the beginning and at the end of spring.

Will Leaf Spot Go Away?

Leaf spots can not go away on their own. In fact, it will keep spreading to other plants in its surroundings if left untreated.

Hence, it is essential to treat leaf spots by removing the affected leaves, covering the soil, or applying fungicide.

In addition to this, if you are treating leaf spots on the lawn, you must know that fungicide treatment will not work after the melting-out phase has begun.

See also  Are Peonies Deer Resistant: (Why Do Deer Eat Peonies)

How Do You Treat Brown Spots on Leaf?

  • Brown spots appear on the leaf because of fungal spores in the air, which are attracted to warm and wet surfaces on the leaf.
  • You can treat them by removing the leaves from the plants.
  • Whether you want to treat garden plants, house plants, or a lawn, the most important thing is to ensure that the leaves or grass blades remain dry.
  • Furthermore, you can use fungicide on houseplants and glass blades to completely eliminate the disease.

FAQs How to Treat Leaf Spot Disease?

Following are some questions that people often have regarding the leaf spot disease.

Q: Should I cut off leaves with brown spots?

Yes, You Have To Remove Affected Leaves.

This Helps Enhance Air Circulation And Allows The Foliage To Get More Nutrients Which Makes The Plant More Green And Healthy.

Q: How Do You Treat Leaf Spots Naturally?

In order to treat leaf spots naturally, you must cut off the affected leaves from the plant.

It would be best if you also attempted to keep the leaves dry. Try not to water the leaves.

If possible, keep the plant away from other plants to prevent spreading.

Q: What Kills Leaf Spot Fungus?

Applying fungicide can help kill leaf spot fungi. There are different fungicides available in the market.

You should try products that contain chemicals such as azoxystrobin, chlorothalonil, iprodione, mancozeb, penthiopyrad, and fludioxonil.


People who love gardening should definitely learn how to treat leaf spot disease because it is a common occurrence and, if left untreated, infect other plants you own.

It is essential to be vigilant and initiate treatment the moment you see spots appear on leaves. You must take action to control leaf spot disease. Otherwise, it can affect your entire lawn or garden plants.

In case your house plant gets infected, you can quickly isolate it and keep it away from other plants to ensure it doesn’t spread. However, this does not mean that all other plants will be safe.

Quick action is required to ensure that all plants remain healthy.