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Why Are My Sunflower Leaves Turning Black? (4 Ways To Save Your Plant!)

Sunflowers are garden-friendly and easy to grow flowers. Most gardeners enjoy planting sunflowers due to their daisy-looking features, broad leaves, and vibrant yellow color. Adding to their physical features, they have a rough hairy stem and are an annual herb.

Although sunflowers are adaptable and easy to grow, still they are susceptible to around thirty different diseases! Yes, you read that right. So if you are worried about why are my sunflower leaves turning black, then there might be a problem.

Many types of sunflowers are widely planted all over the world. They aren’t picky about the soil but require adequate sunlight to grow. Also, they bloom during summers and autumn.

This article gives a detailed view of problems and diseases related to sunflowers to provide you with the answer to your question why are my sunflower leaves turning black?

Why Are My Sunflower Leaves Turning Black
Black edges of sunflower leaves, anyone know what it is? – via Reddit

Why Are My Sunflower Leaves Turning Black

Newly sprouted sunflower leaves can turn black easily if the plant is affected by any fungal or viral infections. The blackness of leaves acts as an indicator to warn the gardener about any prevailing problem. If measures are taken timely, the sunflowers can be saved.

Below are some of the common reasons why are my sunflower leaves turning black.

1. Rust

Sunflower rust is identified by the presence of brown spots on the upper and lower sides of the leaves. These brown spots are caused by Puccinia Helianthi, which is a fungal pathogen that attacks various plants.

This virus is known for attacking the newly developed leaves during the summer season. The fungus continues to survive in winters in the soil and attacks the plant leaves in the following season.

Fungicides are used widely to prevent fungal viruses from infecting already planted sunflowers. Also, to prevent causing sunflower rust, try to plant them early in the season.

The fungal disease can cause plant death if it is not treated timely.

2. Wilting

Sunflower plants are unable to grow without the presence of moisture. If there is not enough moisture present in the environment, the newly grown sunflowers can be subject to wilting of their leaves.

Without sufficient water, the fungi present in the soil attack the sunflower leaves, causing them to turn brown or black.

However, do note that there is some difference between wilting caused due to lack of water and wilting caused by a fungal infection. If watering the plant cures the wilting and the symptoms start to get better, then it might be due to a lack of moisture and water.

But if watering does not work for your problem, it might be due to a fungal infection. Unfortunately, there is no quick fix for this fungal problem. The plant that begins to show the symptoms should be removed to save other plants from getting the disease.

3. Beetle Damage

If the black or brown spots on your sunflower leaves are moving, the spots are due to insects rather than any fungal or viral disease. These insects show up during the summer season and are dependent upon the leaves of your sunflower plant for their survival.

A type of beetle known as the Carrot Beetle usually attacks sunflower leaves and roots. It makes the plant appear wilted and dry, causing stunted growth of plants

Treating your plant with insecticide can discourage the beetles from feeding upon your plant’s leaves. To prevent the spread of the Carrot Beetle, keep an eye on your plant to remove dead and rotten flowers from your plant.

Why Are My Sunflower Leaves Turning Black 2
Black/brown spots on sunflower leaves – via Reddit

4. Leaf Diseases

The most favorable climate for the fungal diseases to affect your sunflower plant leaves is the temperate Mediterranean climate. As soon as the seeds are planted in this climate, the pathogens living in the soil start acting upon them.

As a result, when the new leaves emerge from the seed, they have brown spots present on them. Also, these leaves are dry and delicate and might break very easily.

The use of organic fungicides is the best possible treatment for your dying plant. The sunflower plants should be planted in direct sunlight, with adequate spaces between them, to prevent the cause of leaf diseases.

How Do You Know When Your Sunflowers Are Dying?

A variety of diseases can attack your sunflowers. The treatment is only possible if you identify the presence of the foreign pathogens timely.

If your sunflower leaves turn black, it might be due to overwatering, nitrogen deficiency, aging, or in some cases, underwatering. The leaves can also turn black or brown depending upon the seriousness of the disease.

The growth of abnormal plant leaves or changing of color is a symptom that something needs to be fixed. The life of the sunflower plant can only be saved if treated as soon as possible!

How To Save Sunflowers From Dying?

The issues such as overwatering and underwatering can be easily fixed by adjusting the watering levels of the plant.

If a problem such as nitrogen deficiency or imbalance of nutrients prevails, use fertilizers with high nitrogen content.

If the plant leaves are turning black or brown, look out for its reasons. In most cases, it is due to fungal or viral diseases which affect the plant. The use of fungicides and pesticides can prove to be effective to treat such diseases.

The use of clean gardening tools is very important to stop the transmission of diseases to other plants. The planting of sunflowers should be rotated every year to reduce the possibility of further diseases.


If you planted sunflowers in your garden for the first time and are worried about their leaves turning black, read out this article to find out your answer to why are my sunflower leaves turning black. The change of color can be due to various diseases and the correct identification of the disease is important to begin the treatment.

In case of further questions, feel free to get in contact!