Sunflower Leaves Turning Yellow

Sunflowers are one of the most popular annual flowers in the world. They are grown for their petals, which are used to make a variety of products, including wallpaper and flooring.

Sunflower leaves turning yellow is a common symptom of sunflower leaf scorch. The leaves start to turn yellow and then brown, usually starting at the top of the plant and working their way down.

This is caused by over-watering, too much fertilizer, or a lack of nitrogen in the soil. If your sunflowers leaves are turning yellow, it means you may have overwatered.

You may also have too much fertilizer on the plants. The soil should be moist, but not soaking wet.

Sunflower Leaves Turning Yellow- Identifying Problems And Solution

If you’re noticing your sunflower leaves starting to turn yellow and then dropping off the plant, it’s probably time to investigate the cause and take steps to rectify it.

What Causes Sunflower Leaves To Turn Yellow?

Sunflower leaves turning yellow can be a sign of a number of issues.

Over Watering

Over watering is one of the most common reasons sunflower leaves turn yellow. Sunflower leaves turn yellow and fall off when they get waterlogged.

When water sits on the leaves, it causes them to become heavy and pull down the stem. This can also cause the veins in the leaf to collapse, which results in a yellowing of the leaf.

All plants need water, but too much water will cause problems for your plants and can damage them.

Try to follow a watering schedule that focuses on letting the soil dry out between watering’s, and don’t water your plants when it is raining or snowing.

Nutrient Deficiency

Sunflower leaves may turn yellow if the plant is deficient in a specific nutrient. Deficiencies of nitrogen, phosphorus, potassium, and calcium can all cause leaves to turn yellow.

Sunflowers need these nutrients to grow healthy flowers and produce seeds. Plants that have been grown in nutrient-poor soils for a long time may be deficient in nitrogen, calcium, or both.

When this happens, the plant will produce yellow leaves instead of green leaves. Some people report that zinc deficiency also causes sunflowers to turn yellow.


Sunflower leaves typically turn yellow during warm weather because the plant’s photosynthesis process is slowed down.

Sunflowers use the sunlight to convert carbon dioxide and water into glucose, which provides energy for growth and reproduction.

When temperatures rise too high, the plant cannot cool itself sufficiently and its enzymes become ineffective in breaking down these complex molecules. This lack of glucose causes the leaves to become yellow.

Fungal Infection

A fungal infection is a reason for sunflower leaves to turn yellow. Fungi can invade the plant’s vascular system and block the flow of water and nutrients to the leaves, turning them a pale yellow or even brown.

Although fungal infections are often benign, they can also lead to leaf destruction and reduced yields. If you notice yellowing or wilting on your sunflowers, it might be time to take action and get your plant treated for a fungal infection.

Viral Infection

Sunflower leaves turn yellow and fall off when they get a viral infection. Viruses cause this problem by infecting the plant’s cells, and then the cell walls start to break down.

This makes it difficult for the plant to take in water and nutrients, and eventually the leaves die. There are many different viruses that can cause sunflower leaves to turn yellow, but most common is the leafminer virus.

Small viruses can pass through the cell walls of the plant and infect the plant’s cells. This causes the cell walls to break down and eventually leads to yellowing of the leaves.

Check This Out: Why Are My Potato Leaves Curling

Brown or Black Spots Appearing on The Yellowing Leaves Of Sunflowers

Sunflowers are one of the most popular flowers in the world, but many people do not know what causes sunflowers to turn brown or black spots.

Brown or black spots, often on the yellowing leaves, can be a sign that the sunflower is experiencing some type of disease.

It’s important to identify and treat any diseases as soon as possible so that the sunflower can continue to produce flowers and yield crops.

The yellowing leaves are also a sign of old age can give sunflowers a brown or black spot appearance.

How to Treat Sunflower Leaf Yellowing?

Sunflower leaves turning yellow can be a sign of a number of issues, but with the right treatment, it can be easily cured.

Using Good Fertilizer

Sunflower leaves that have turned yellow are a symptom of nutrient deficiencies. The most common deficiencies are nitrogen, phosphorus and potassium.

To correct these deficiencies, sunflower growers need to apply a fertilizer that contains these nutrients. Fertilizers that contain these nutrients include fish meal, ammonium phosphate and ammonium sulfate.

Apply the fertilizer according to package directions. When fertilizer is applied, the leaves will usually recover within a few weeks.

Adequate Water

Sunflowers need adequate water to remain healthy when their leaves turn yellow, it may be time to water them more frequently. Yellowing is usually a sign that the plant needs more water than usual.

If your sunflower is wilting or drooping, has sparse growth, or develops brown patches on the leaves, it might be in need of supplemental irrigation.

Try drenching the plant with a hose or filling a tub or container with water and soaking the roots until the soil feels wet before watering.

Remove Bugs

Sunflower leaves may turn yellow and die if there are bugs on them. To remove the bugs, first identify which type of bug is on the leaf, then do one of the following:

If it’s a beetle or caterpillar, use a hand lens to spot where they are located and squish them; if it’s a spider, kill it with a vacuum cleaner.

Check This: How To Get Rid Of Bugs In Houseplants?

What Are The Signs That Sunflower Leaves Are Turning Yellow?

Sunflower leaves are turning yellow when the plant is stressed. Symptoms of stress can be water deficiency, excess nitrogen, a lack of light, or pests. Stressed plants also have red, yellow or brown tips on the leaves.

How to Treat Yellow Leaf Sunflowers?

Sunflower leaves may start turning yellow and dropping off early this season if there is an extended cold snap. If you are noticing this issue with your sunflowers, some tips to help them recover are outlined below:

  • Remove any dead or Dying leaves. This will help to improve airflow and encourages new growth.
  • Water the plants regularly, especially during dry spells. Make sure the water is deep and well absorbed. If water is not available, try using a garden hose to provide direct flow over the plants foliage.
  • In the event of a freeze, you may want to cover the plants with black plastic or heavy blankets.
  • You should control weeds during the summer and fall months, but do not let them get too far away from your sunflowers as they will compete for nutrients.
  • Feed your sunflowers during the spring and summer months with a balanced fertilizer formulated specifically for your plants.

Sunflower Leaves Turning Yellow

How Do I Care For Sunflowers?

Sunflowers are a great addition to any garden, but they can be difficult to care for. Here are some tips on how to help sunflowers thrive:

1. Plant sunflowers in full sun or part shade.

2. Water them regularly, but don’t overdo it.

3. Mulch around the plants to keep the soil cool and moist.

4. Snip off the faded flowers to keep the plants looking fresh and blooming.

5. Fertilize them once a month with a balanced fertilizer, using half of what you would use      for roses or tomatoes.

6. Fertilize them as well with a product made for sunflowers.

7. Prune off the dead or faded blooms to encourage new growth and keep the plant                looking-fresh.


If you see yellow leaves on your sunflower, there may be a number of issues that need to be addressed. It is important to determine the cause and seek treatment as soon as possible.

Often, simple solutions can be found that will restore the plants to their healthy condition. So if you notice yellow leaves on your sunflower, don’t give up hope – there’s likely a solution available.