Yellow Spots On Apple Tree Leaves? [4 Reasons With Control Measure]

Four factors are responsible for yellow spots on apple tree leaves. They are Diseases, Pests, a Stressful Environment, and a Lack of fertilizers. 

Your apple tree may be infected by any one or more of these four factors. So your first task is to identify the root cause. After that, if proper measures are taken accordingly, the affected leaves can be fixed quickly.  

You must be thinking about how to find out the real reason. No worries, I will tell you all the possible reasons to fix the yellow spot on apple tree leaves in this article. So stay with me and read the article till the end.

4 Effective Ways To Fix Yellow Spots On Apple Tree

 Spots On Apple Tree Leaves

1. Disease

A fungal disease called cedar apple rust is the leading cause of yellow spots on the leaves of apple trees. One or more circular yellow spots develop along the borderline of the leaves of erosive plants. Sometimes red or brown dots are seen between them. If the infection reaches the severe stage, such spots also appear in the fruits.

This problem of apple trees is more common during the growing season. This can cause your plants to curl, turn brown and drop their leaves, stunt fruit growth, lose fruit, and even kill the plant.

The infection starts from the top leaves of the plant and gradually spreads downwards. New leaves are usually the main target of these fungi. These fungi can also cause the formation of galls, which are small, hard, and round growths on the branches of the tree.

Control Measure

The good news is that although cedar apple rust is quite fatal, it is treatable. But for that, you need to maintain some proper strategy. If proper guidelines are followed, affected plants can be cured within seven to ten days.

When you confirmed the infestation, you should first remove the affected leaves and fruits as soon as possible. This is the most effective way to prevent infection in the first stage.

Culprit fungi try to reproduce by producing spores on various branches of the affected plant that is very close to the affected leaves. The presence of a powdery substance on the branch should be pruned. But care should be taken not to damage healthy branches.

A quality fungicide should be sprayed over the entire tree after pruning. Besides, it is more effective to plant rust-resistant varieties before planting trees. Regular tree maintenance and the surroundings of the tree should be kept clean.

2. Pests

Aphids and apple maggots are two of the most responsible pests for yellow spots on apple leaves. Aphids are pear-shaped soft-bodied insects and can grow up to 5-10 mm in size. They stop plant growth by sucking sap.  

During this time, they release a sticky substance called honeydew, which is responsible for creating yellow or orange spots on the leaves. If the same substance comes in contact with the fruit, the fruit also spoils.

A bug called an apple maggot infested apple trees, causing harm to the leaves and fruit. The larvae of the adult flies burrow into the leaf and feed on the flesh after the eggs hatch. The adult flies lay their eggs in the skin of the leaves. The leaf may develop brown spots and turn yellow as a result.

Control Measure

For aphid control, you need to take some planned steps. First of all, you have to pay attention to the number of insects. Since controlling them is quite a tough task, the amount should be reduced gradually.

Pruning is most effective in this regard. The number of pests should be reduced by pruning the most infested parts. Then spray the entire plant with fresh water and wipe each branch with a clean cloth. The tree should be monitored for the next few days.

If the infestation does not subside, you may want to consider insecticides. A good quality chemical can quickly rid your apple tree of aphids. Apart from this, aphids can be controlled using natural parasites like ladybugs, and lacewings.

Sticky traps are the most effective way I have found for apple maggot control. And it’s very easy. All you have to do is apply some gum to a square tray and hang it on the tree. The insects themselves will get trapped there and die. You can also eliminate them by applying pruning, sanitation, and insecticides.

3. Lack of Fertilizer

If pests and diseases are not responsible for causing yellow spots on your apple tree leaves, you should be concerned about insufficient fertilizer. If your apple tree is not getting enough nutrients, the leaves of the tree can become spotty.

Basically, nitrogen deficiency causes the yellowing of plant leaves which is called chlorosis. The photosynthesis process is disrupted in plants due to a lack of sufficient nitrogen. As a result the cells of the leaves gradually die. At this time, the leaves of the tree first turn yellow and then turn brown.

Apart from this, due to manganese deficiency, plant enzyme, and hormone synthesis stop. In this case, the plant’s growth will also be disturbed along with spots on the leaves.

Control Measure

Plants usually get all their nutrients from the soil. So good quality soil is essential before planting. In general, apple trees prefer soil that drains well and has a pH between 6.5 and 7.0. They typically thrive in loamy soil that is rich in organic matter so it is best to apply organic compost to the soil.

Apple trees require appropriate nutrients and moisture in addition to proper drainage and a pH that is neutral for them to grow. Regular fertilization with a balanced nutrient, such as an NPK (10-10-10 or 20-20-20) composition, is beneficial to them. However, proper instructions must be followed before using any chemical. 

You can also apply manganese oxide fertilizer separately to the soil to compensate for manganese deficiency. Crops such as beans and peas are also effective in increasing soil manganese abundance.

4. Stressful Environment

Apart from the things discussed above, if the apple tree does not get a suitable environment such as the proper amount of water, temperature, humidity, and sunlight, spots can also occur on the leaves.

Control Measure

Apple trees need to be watered 1-1.5 inches once a week. However, the amount may be less or more depending on the rainfall.

Apple trees grow faster in bright full sun. So, plants require seven to eight hours of full sun per day. However, shade should be provided to protect the plant from the afternoon sun.

Apple trees grow best in a climate with cool winters, medium heat in summers, and moderate humidity.

Frequently Asked Questions (FAQs)

What Does Fungus Look Like On An Apple Tree?

Certain symptoms can easily identify Apple trees infected with the fungus. The leaves will turn pale and have black, brown, or yellow spots on the leaves, a powdery substance can appear on the branches, and sometimes bumps can form and canker on the plant.

Do Apple Trees Need A Lot Of Fertilizer?

Apple trees generally don’t need a lot of fertilizer. But that is why it is important to select quality soil. If your soil has all kinds of nutrients then good. However, if the soil is nutrient deficient, the tree is relatively young and the tree is affected by certain diseases, additional fertilizers should be applied to the tree according to the correct rules.


Fungi and insects are mainly responsible for causing yellow spots on apple tree leaves. So you need to be aware of these two factors. Regular tree care and keeping the garden clean can usually keep plants away from these two issues.

But even if the tree is affected in some way, without worrying, the proper measures should be taken in time. If you follow the guidelines I have discussed, you can easily fix your infected apple tree. Happy Gardening.

James Rivenburg
James Rivenburg
James Rivenburg

James Rivenburg is the founder of, a passionate gardener with valuable experience and knowledge gained through trial and error. The website has a large community of followers who trust his tips and techniques and have succeeded with his advice. He is always Committed to helping others create a beautiful and healthy garden.

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