Brown Spots on Hydrangea Leaves: Reasons & Fix

Do you take pride in your beautiful garden filled with hydrangeas, only to notice unsightly brown spots on the leaves? Don’t fret, you’re not alone. Brown spots on hydrangea leaves are a common issue faced by many gardeners, and it can be concerning.

In this blog post, we will discuss the causes of brown spots on the leaves of Hydrangea and provide tips on how to treat it and fix the problem. We will also emphasize the importance of proper care and maintenance for hydrangeas to prevent future issues.

By the end of this post, you’ll have the knowledge and tools to tackle this issue easily.

Brown Spots on Hydrangea Leaves

Let’s get started!

Reasons Why do my hydrangeas have brown spots on the Leaves

Here are some of the most common causes of brown spots on hydrangea leaves:

Transplant Shock

If you recently transplanted your hydrangea, it may be experiencing transplant shock. This is a common problem that occurs when a plant is moved from one location to another.

Symptoms of transplant shock include wilting, yellowing leaves, and brown spots. To prevent transplant shock, make sure to water your hydrangea thoroughly before and after transplanting.

Fertilizer Burn

Hydrangeas require regular fertilization to thrive, but too much fertilizer can cause fertilizer burn. Symptoms of fertilizer burn include brown spots on the leaves, wilting, and stunted growth.

To prevent fertilizer burn, make sure to follow the instructions on your fertilizer package and avoid over-fertilizing your hydrangea.

Fungal Diseases

Fungal diseases, such as Cercospora leaf spot or Colletotrichum gloeosporioides., can cause brown spots on hydrangea leaves. These diseases are often caused by high humidity and poor air circulation.

To prevent fungal diseases, make sure to water your hydrangea at the base of the plant and avoid getting the leaves wet. You can also improve air circulation around your hydrangea by pruning any overgrown branches.

Insufficient Watering

Hydrangeas require regular watering to stay healthy, and insufficient watering can cause brown spots on the leaves.

Symptoms of insufficient watering include wilting, yellowing leaves, and brown spots. To prevent insufficient watering, make sure to water your hydrangea deeply once a week, or more often during hot, dry weather.

Too Much Sun

Hydrangeas prefer partial shade and can suffer from sunburn if they are exposed to too much sun. Symptoms of sunburn include brown leaf spots and wilting.

To prevent sunburn, make sure to plant your hydrangea in a location that receives partial shade, especially during the hottest part of the day.

How to Fix Brown Spots on Hydrangea Leaves?

Here are the ways to fix the brown spot issue:

Remove affected leaves

If you notice brown spots on your hydrangea leaves, it’s crucial to remove them promptly to prevent the disease from spreading.

Use clean pruning shears or scissors to carefully trim and dispose of the affected leaves.

Ensure proper watering

Insufficient watering can lead to brown spots on hydrangea leaves. Make sure to water your hydrangea deeply at least once a week, especially during hot and dry weather.

Ensure the soil is adequately moist, but avoid overwatering as it can cause other problems.

Apply fungicide

If your hydrangea is suffering from a fungal disease causing brown spots, applying a fungicide can be beneficial.

Follow the instructions on the fungicide packaging precisely to apply it correctly. This helps control the spread of the disease and encourages healthier foliage.

One of the best fungicides recommended for hydrangea leaf spot is chlorothalonil.

Chlorothalonil is a broad-spectrum fungicide that provides excellent control against various fungal diseases, including leaf spots.

When using chlorothalonil or any fungicide, it’s crucial to carefully read and follow the instructions on the product label. This ensures proper application and adherence to safety precautions. Consider the following tips:

  1. Purchase a chlorothalonil-based fungicide that is labeled for hydrangea leaf spot control.
  2. Mix the fungicide according to the instructions provided on the product label. Follow the recommended rates and application timings.
  3. Apply the fungicide evenly to all affected parts of the hydrangea, ensuring thorough coverage of the leaves, stems, and other affected areas.
  4. Reapply the fungicide as directed on the label. This is usually necessary every 7 to 14 days, depending on the severity of the leaf spot and the specific product’s instructions.
  5. Take precautions to prevent the fungicide from coming into contact with beneficial insects, bees, or other non-target plants. Follow any guidelines regarding waiting periods before harvesting edible parts of plants, if applicable.
  6. Store the fungicide properly, following the manufacturer’s recommendations, and keep it out of reach of children and pets.

Adjust fertilizer usage

Overfertilization can cause brown spots on hydrangea leaves. Review the instructions on your fertilizer packaging and adjust the amount and frequency accordingly.

Following the recommended guidelines prevents fertilizer burn and maintains leaf health.

Provide shade

Hydrangeas can experience sunburn, resulting in brown spots. Shield your hydrangea from intense sunlight by providing partial shade during the hottest part of the day.

Relocate potted hydrangeas to a shadier area or use shade cloth as protection.

Natural Treatment for Brown spots on Hydrangea leaves

If you prefer natural treatments, there are several options you can consider to address brown spots on hydrangea leaves:

1. Neem oil

Neem oil is a natural fungicide and insecticide that can help control fungal diseases and pests.

Dilute neem oil according to the instructions on the product and spray it on the affected leaves. Repeat the application every one to two weeks as necessary.

2. Baking soda solution

A baking soda solution can be effective against fungal diseases.

Mix one tablespoon of baking soda with one gallon of water and spray it on the affected leaves. Apply this solution every two weeks or after rainfall.

3. Milk solution

Milk has antifungal properties and can help combat fungal diseases in hydrangeas.

Mix one part milk with nine parts of water and spray it on the affected leaves. Apply this solution once a week.

4. Chamomile tea

Chamomile tea can act as a natural fungicide. Brew chamomile tea using tea bags or dried chamomile flowers and let it cool. Strain the tea and spray it on the brown spots. Apply this treatment once a week.

Additional Tips for Hydrangea’s brown spots on leaves

  • Ensure good air circulation around your hydrangeas to reduce the chances of fungal diseases.
  • Avoid overhead watering, as wet foliage can contribute to fungal growth.
  • Regularly inspect your hydrangeas for signs of pests, as some infestations can cause leaf discoloration.
  • Pruning your hydrangeas annually can improve their overall health and appearance.
  • Mulching around the base of the plants can help conserve moisture and maintain more stable soil temperatures.

By following these steps and considering the additional information, you can effectively address brown spots on your hydrangea leaves and promote a healthy and vibrant plant.

Remember to provide the necessary care, such as proper watering, fertilization, and maintenance, to keep your hydrangeas thriving for years to come. To know the complete details on Hydrangea care, you can check this guide here.

Can Using Bone Meal on Hydrangeas Cause Brown Spots on the Leaves?

Using bone meal for hydrangeas may result in undesirable brown spots on the leaves. While bone meal can provide valuable nutrients to plants, the high levels of phosphorus present in bone meal can lead to phosphorus toxicity in hydrangeas. This can manifest as brown spots on the leaves, negatively impacting the overall health and appearance of the plant. It’s crucial to carefully consider alternative fertilizers or adjust the quantities of bone meal used to prevent such issues.

Frequently Asked Questions

How do you get rid of brown spots on hydrangeas?

To treat brown spots on hydrangeas, you should remove affected leaves, ensure proper watering, apply a fungicide such as chlorothalonil, adjust fertilizer usage, and provide shade to prevent sunburn.

Why do my hydrangeas have brown spots on the leaves?

Brown spots on hydrangea leaves can be caused by fungal diseases such as Cercospora leaf spot or Colletotrichum gloeosporioides. These fungi can spread through water droplets on the leaves, so overhead watering or rainfall can contribute to the spread of the disease. Over-fertilization or a wet environment can also increase the likelihood of brown spots on hydrangea leaves.

Should you cut off brown hydrangeas?

If the hydrangea bloom is completely brown and dead, it’s best to cut it off as it will not produce any more flowers. However, if the bloom is partially brown but still has some color, it’s possible that it may continue to produce more flowers, so it’s best to leave it on the plant. Additionally, pruning hydrangeas after flowering can encourage reblooming in some cases.

What does a fungal leaf spot on Hydrangeas look like?

Fungal leaf spots on hydrangeas can manifest as brown, black, or gray spots or angular blotches on the leaves. These spots may be surrounded by a reddish or purple halo, and the severity of the spotting can range from mild to severe.

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