How to Get Rid of Black Spots on Hydrangea Leaves? –ISBUZZLE

Oakleaf Hydrangea is a type of flowering plant native to the southeastern United States. It is an ornamental plant much sought after for its flowers.

It appears as a whitish-pink flowering shrub with four seasons of interest and blooms and grows best in warm regions and during the months of May through July.

The plant’s flowers grow in large clusters, while the leaves are large and distinctive. The flowers are known to be originally white, gradually turning purplish pink.

The plants grow well in slightly acidic, well-drained soil and are not too demanding. fertilizers. They can be easily propagated by cuttings.

Although these plants are quite gorgeous and have attractive foliage, spotting can spoil the beauty of the leaves. But they are not necessarily lethal to the plant.

The black spots on the leaves of your hydrangea are mainly caused by the Cercospora fungus. These are fungi that live in the soil and are transferred to the leaves by rain or water.

Cercospora will usually have infected your plant for 1-2 months before your hydrangea starts showing the black spots, which is common from summer through fall.


What are black spots on a hydrangea leaf?

Pink hydrangeas with green leavesThere can be several reasons why hydrangea leaves have black spots.

They can be the result of bacterial or fungal infestation, poor air circulation between plants, dense branches/stems, especially at the base of the plant, excessive humidity, overhead sprinklers and heavy rains.

1) Bacterial stains

Xanthomonas species often cause bacterial leaf spotting. These spots appear on the leaves of plants that are kept in extremely humid conditions.

2) Fungal spots on the leaves

Many different fungi can cause fungal leaf spots. Some fungi that affect the plant are:

1) Cercospora Mushrooms

Fungal spots are usually caused by the fungus Cercospora. These fungi live in the soil and are transferred to the leaves by rain or water.

Spot symptoms take almost a month or two to appear on the leaves. This fungus normally infects plants in the fall.

2) Blackhead Fungus

Black spot on hydrangea leaves can also develop from black spot fungus.

Black spot fungus appears in the spring when temperatures rise to the 1960s and the garden stays wet for more than six hours.

When the temperature reaches the 70s, the disease progresses until the temperature exceeds 85 F.

At first, the infection appears as small black dots, which are later covered with a ring of yellow tint. This can lead to complete yellowing of the sheet.

3) Coletotrichum

Anthracnose, also characterized by brown to black spots, is caused by Colletotrichum species. The spots range from dark brown to black with tawny centers.

The distinguishing characteristic of this fungal infection is that the spots appear on both the leaves and the flowers of the plant.

Anthracnose, if severe, can kill your plant. All symptoms of a fungal infection worsen in summer during heavy rains. Plants rarely flower during infection.

The spots are not fatal to the plant and the leaf spotted hydrangea usually survives, but is slow growing and may droop and drop leaves prematurely.

The spots appear first on the lower old leaves, then on the new shoots.

If you like this article, check out our article on Why are the leaves of my hydrangea curling?

Are black spots on your hydrangea leaf a bad thing?

Blackheads are visually bad. They ruin the beauty of the plant and if one of your plants gets infected, it can ruin the beauty of our flower bed or garden.

It’s a shame if you carefully plant several plants in your garden and some of them turn out to be infested with fungus as this requires careful control.

Black spots on hydrangea leaves are not fatal. The plant can still grow, although the growth rate has slowed.

Infection, if severe, can cause defoliation and loss of vigour. Black dots indicate wet, damp conditions and poor sanitation in the yard.

They also indicate fungal growth in the soil. Therefore, the spots can act as indicators that you need to pay attention to your beloved garden and its inhabitants and require the use of fungicides.

It is best to act quickly to remove the infected parts of the plant so that the fungus does not infect other beautiful plants in your garden.

How to Get Rid of Black Spots on Hydrangea Leaves?

a blue hydrangeaWe all know that prevention is better than cure. So we start with ways to prevent damage to your plant.

1) Thin and cut the stems of your hydrangeas in the spring. Remove 1/3 of education from older stems. You can also remove the stems after flowering.

This promotes air circulation through the leaves, evaporating moisture and keeping the leaves dry.

2) Avoid over-fertilizing your hydrangeas, as too much fertilizer makes the plant more susceptible to disease.

Instead, try using a slow-release organic fertilizer instead of a chemical fertilizer.

3) Avoid using overhead sprinklers or watering hydrangea leaves. Instead, water the base of the plant first with a garden hose or drip hoses.

If you want to use a sprinkler, be sure to use it in sunny weather and the soil is not too wet between waterings.

4) Discard diseased leaves, stems and flowers that you have removed from affected hydrangeas and keep the infected plant away from the rest of the lot to minimize the risk of cross-contamination. Do not use diseased leaves as compost.

5) Don’t forget to clean up dead leaves around your plants in late fall.

6) If you are concerned about re-infection the following season, it may help to spray new hydrangea leaves with a fungicide every 10-14 days on shrubs damaged last year.

Don’t forget to spray the stems and undersides of the leaves as well.


Fungicides can be applied if its leaves are affected by fungus. Copper-based fungicides are preferred for this.

Fungicides containing chlorothalonil and thiophantate methyl control both Sigatoka and anthracnose.

Treating already damaged leaves is not an effective or meaningful option, as the leaves will eventually drop in the fall.

Adopting good hygiene habits is the best solution to combat recurring black spots on the leaves.

Thoroughly clean off damaged and infected leaves as they fall. Water splashed from infected plants should also not spread to adjacent leaves or neighboring plants, as this can transfer the spores.

When landscapingthen choose disease-resistant hydrangea plants.

This would reduce the risk of fungal infection and minimize the risk of recurrence and spread.

Check the nursery to make sure you are buying a disease resistant plant.

Natural medicine:

take oil works well in the treatment of black leaf spot. It is a natural oil obtained from the leaves of a evergreen tree. It works to eliminate fungus.

Mix baking soda and a little horticultural oil. You can also make a solution that treats blackheads by changing the pH so the mold doesn’t survive the pH change.

Begin preventive spraying before the temperature reaches sixty. Read the label and instructions for the method you choose and follow them carefully.

There are also other all-natural methods for treating leaf spots on hydrangeas, such as spraying the leaves with compost tea, liquid seaweed, garlic oil, or hydrogen peroxide.

compost tea the dining room came out after a few days of soaking the compost. Compost tea uses beneficial bacteria to kill bacteria that cause leaf spots.

Remember to use diluted garlic oil for spraying purposes. diluted hydrogen peroxide in 8 times the quantity to be used. Avoid contact with hydrogen peroxide on the skin.

If you are new to planting hydrangeas in your garden, here are some tips:

  1. Plant hydrangeas in areas that receive direct sunlight.
  2. Use a well-drained potting mix if planting in a container.
  3. Avoid watering at night.
  4. Do not water your plant, prefer water tables.
  5. Make sure your tools are clean and always launder your tools after cutting or handling fungus-infected plants to avoid the risk of spreading them.
  6. Use organic matter or compost in the soil before planting your plant.
  7. Spread a layer of mulch several inches from the stem of the hydrangea and remove it each winter.
  8. Use a low nitrogen fertilizer.
  9. Spray fungicides every 2 weeks when new growth begins to appear.

final thoughts

A purple hydrangea with green leaves.Native to the United States, the oakleaf hydrangea has beautiful blooms and foliage, but black spots can be distracting and spoil the beauty of your plant.

Fortunately, black spots caused by fungus or bacteria are not fatal to the plant and can be easily avoided by practicing strict sanitation techniques and avoiding overwatering.

Wet conditions encourage mold growth, so allow plenty of time. water.

Using neem oil and other home remedies like baking soda and compost tea can prevent the risk of recurrences and kill the fungus already present on the leaves.

Following a few simple tips when planting hydrangeas and using clean tools can prevent damage to your precious plants.

Before you go, here are some other related articles that I encourage you to read below to solve more of your gardening problems:

Why are my hydrangeas turning green?

Snowball shrub against hydrangea

Why does my hydrangea have small flowers?

How to use baking soda to grow hydrangeas

About the Author:

sad gosling

Saad is an avid gardener and a great lover of plants, animals, photography and people. He currently focuses on indoor plant photography and capturing beautiful landscapes. Write and rewrite feature articles on nature and science.

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