Yellow Leaves with Brown Spots: The Causes and Solutions for this Plant Problem

Yellow leaves with brown spots can leave gardeners feeling very discouraged and disheartened. No matter how diligent and experienced a gardener is, a time will come when those tiny brown circles will appear on the leaves of your plant.

A common gardening question that comes to mind is, “why are my plants turning yellow with brown spots? Although there are many reasons your plant may have brown spots, most of them include Overwatering, sunlight, and excessive fertilizer, the most common is Leaf Spot Disease.

Leaf Spot Disease

Leaf Spot is a limited discolored common fungal or bacterial infection that plagues houseplants. If you keep seeing brown or black spots on the leaves of your plants, that means your plant has been infected with leaf spot disease. 

Leaf Spot Disease
Leaf Spot Disease.

The spots vary in size and are seen on the leaf surface. They are also irregular and measure between 3/16 and ½ inches (0.5 to 1.5cm) wide. Plants won’t die from leaf spot fungus because most trees can tolerate leaf spots with little or no apparent damage.

However, leaf spot disease should be taken seriously, especially if they have been leaf loss for more than two years. Most times, you will spot the infection on lower or inner branches, and the shape of the spots can vary from circular to angular.

When infected, the first sign is usually a grouping of small brown spots that can sometimes merge to form larger areas of browning or reddish-brown spots over the leaf.

Common Leaf Spot Disease

Leaf Spot Disease

Here are some of the most common Leaf spot diseases. They include;

1 . Septoria Leaf Spot

Septoria Leaf Spot can be described as round with black margins. When plants are infected, the leaves will wilt and blacken, then fall to the ground where the spores will overwinter.

2. Cedar-Apple Rust

This disease is most common in apples and crabapples. It can cause damage to leaves and fruit of apple varieties. However, it is only a minor problem on resistant or partially resistant trees.

3. Anthracnose

Anthracnose is a fungal disease group that affects various plants in warm, humid areas. It is found in several plants, including grasses and annuals. Though its symptoms vary from host to host, the most common include; irregular spots, dead areas on leaves, etc.

4. Venturia

When a plant is infected with venturia, brown and black spots form in early spring, causing irregular leaves. The infected shoots turn black and weaken, so the stems twist and contort.

Cause Of Leaf Spot Diseases

Multiple ways trigger leaf spot disease to appear on plants. They include;

1 .  High Humidity levels paired with poor airflow and circulation.

2. Over-misting foliage.

3. Fluctuations in temperature.

4. Overcrowded plants.

5. Lack of sunlight and airflow.

6. Wet Conditions.

Ways To Treat Plant Leaves Turning Yellow With Brown Spots

It is advisable to hire an arborist if you have significant leaf spot problems. However, there are many treatments and preventive steps you can use.

1 . Prune and remove the affected leaves. Properly rake up and destroy the infected fallen leaves and broken and pruned branches.

2. Frequently use the treatment of neem oil or another fungicide on the foliage. Though copper-based fungicides are safe and effective for most plants, make sure you conduct your research because copper can be harmful to certain plants.

3. Avoid watering the leaves. Instead, could you leave it to recover.

4. Keep the affected plant away from other plants temporarily to prevent the infection from spreading to the foliage of other plants.

5. Ensure you monitor the plants daily to know if the Infection has stopped.

6. Repeat the steps until you are sure the plant has fully recovered.


Like they always say, “Prevention is better than cure.” To prevent the leaf spot disease from taking out your plants, try these tips and tricks.

1 . Provide good air. Place the plant in a location where it can get a sufficient amount of good air, especially during summer when it gets hot and humid.

2. Avoid misting or splashing; apply water to the soil and root zone but be careful not to wet the leaves because wet conditions promote disease. Avoid sprinklers; instead, use a drip or soaker hose.

3. Do not overcrowd the plants. Give the plants more breathing room, so don’t bump leaves with other plants. Prune trees or shrubs to increase light penetration and helps to improve air circulation.

4. Use neem treatment. Spray your plants with neem oil to serve as a preventive method against bacteria, fungal, and pest issues. This treatment will help catch any early start of leaf spots before it spreads beyond control.

Frequently Asked Questions

1 . What Is The Best Fungicide For Leaf Spot?

Patch pro has proven to be the top recommendation to control leaf spots. The product contains active ingredients like propiconazole which works actively to eliminate and control leaf spots and prevent them from spreading. Also, chemicals like chlorothalonil, copper mancozeb, Iprodione, and thiocyanate methyl are recommended, and each has active ingredients.

2. Should I Cut Off Leaves With Brown Spots?

Prune dead plants, dormant stems, or brown parts of leaves. It is okay to pluck them with your hands, but be careful not to pull too hard because you may likely damage the healthy part of your plant. For more rigid stems, use scissors or pruning shears.

3. Can Brown Leaves Turn Green Again?

The brown leaf may likely not turn green again, but you can trim the edges to get the plant looking healthy again.

4. How Do You Tell If Underwatering Or Overwatering?

Telling the difference between the two can be pretty confusing. If the soil is wet, it is overwatered, but if it is dry, it is underwatered.

5. Can Leaf Spots Spread?

Leaf Spot can spread to your other plants in no matter of time. That’s why it’s advisable to isolate the Infected plants away from the other plant when you notice any sign of Infection.

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