Why Do Sunflower Leaves Turn Yellow?

why do sunflower leaves turn yellow

Why do sunflower leaves turn yellow? Flowers are beautiful to behold. It will make people happy because the surroundings become great to watch.

When you have a sunflower garden there are times that some of your plants will have a problem. You need to fix the problem as soon as possible so that the plants will live longer and the flowers will bloom great.

Why Do Sunflower Leaves Turn Yellow?

Some of the possible reasons why there are yellow leaves on sunflower plants are; lacking sunlight, watering problems, lacking nutrients, damaged roots, pests, diseases, and sunflower leaves are just old.

The problems will depend on many factors and you need to identify the cause and the appropriate solution to the problem. When the problem is just a little, then the sunflower plant may recover quickly and you can fix it easily.

Sunflower Plants Are Lacking Sunlight

Sunflower plants love sunlight and they must receive at least 6 hours of sunlight per day. If you try to observe, most sunflower gardens are located in an open area. An area where it is a little bit far from any tall trees. Tall trees will create a shade under or near to them so it is better to grow a plant a few distances away from them.

It feels great to visit a sunflower garden and you can take a lot of pictures. That is why some people try to make a sunflower garden in their homes. A mini garden with a lot of flowers.

Growing sunflowers is challenging especially if it is your first time growing this kind of flower. Yellow leaves and brown leaves on sunflowers may appear if they are not getting enough sunlight so you need to make sure they are getting their needs regularly.


Sunflower plants need water in order for them to grow. But the good thing about sunflowers is they are drought tolerant. Since they are drought tolerant they can grow and live for a couple of days or weeks without getting water or receiving only less water.

Watering sunflower plants less often will not be a problem. The problem in watering sunflowers is getting them overwatered. When overwatering occurs, yellow leaves and losing leaves on sunflower plants will happen.

You need to be careful in giving water to your plants to prevent them from getting too much water. The right amount of water will make them safe and keep them thriving. Caring for sunflower plants is very important to do as a gardener.

Damage Roots

Too much water can cause the sunflower roots to get damaged. It can happen if you overwater the plants or a heavy rainfall comes and your plants get flooded.

If the roots of sunflower plants get damaged, the yellow leaves may appear on the plant. It may happen because the root functions are not working well. The plant cannot get water and nutrients which affects the growth of the plant.

In some cases, gardeners grow sunflowers in a pot but then it gets waterlogged because of poor drainage which causes the leaves to turn yellow. You need to make sure that the pot you are going to use has good drainage and it is great if you also use well-draining soil.

Lacking Nutrients May Cause Yellow Leaves On Sunflower Plant

Nutrients are essential for sunflower plants’ growth. They need nitrogen and iron to maintain their leaves green. Lacking nitrogen and iron can cause yellow leaves so it is important to improve nutrients in the soil.

Iron deficiency will happen if there is lacking iron in the soil. The plants will have less chlorophyll when this particular element is missing in the soil. The chlorophyll is important for the sunflower because it will work to convert sunlight into food.

Aside from nitrogen and iron, there are other elements needed by sunflowers such as phosphorus, potassium, etc. But you also need to prevent over-fertilizing so that flowering will not be delayed.

Transplant Shock

If a mature sunflower plant is transferred to a new location, transplant shock may happen. You need to be careful in handling and transferring the plant to keep them alive and thriving.

Transplanting mature plants needs more care than transplanting sunflower seedlings. It is not common to transplant old plants because they have already long roots and are already established. It is best to transplant a plant when they are still young.

You need to give the plant water as soon as possible. The leaves on sunflowers will curl if they do not get water quickly.

Pests And Diseases Attack Sunflower Plant

Some numerous pests and diseases may attack the sunflower which can cause yellow leaves to appear. You need sunflower pest control as well as disease control to keep the plant healthy.

Some of those pests that may attack sunflowers are; aphids, mites, thrips, etc. Slugs, snails, squirrels, and birds may also damage the plant. You can use pesticides to control them or make a barrier to prevent animals like squirrels from going into the garden.

The sunflower plant lifespan will be in good shape if there are no pests on the plant. Aside from pests, diseases like downy mildew, fusarium, pythium, phytophthora, and Rhizoctonia may also cause some damage to the sunflower. You can use fungicides to control diseases on the plant.

Age Sunflower Leaves

If a leaf gets old, it will turn yellow. It is common to see yellow leaves on any plant because it is part of their growth. Sometimes you do not need to worry if you see some yellow leaves.

Most of the yellow leaves may grow underneath other leaves. The old leaves turn yellow and new leaves grow on the plant. You need to observe and analyze your plant to confirm whether they are old leaves or if there are other factors causing them to show on the plant.

It is great to know why sunflower leaves turn yellow. By keeping the plants healthy, the yellow leaves may be prevented. The beautiful flowers will appear very soon.