Why are My Apples Bumpy? Culprits Behind Uneven Apple Surfaces

Have you ever taken a bite out of an apple only to discover a bumpy texture? While we often associate apples with smooth and crisp surfaces, encountering bumps can be puzzling. In this article, we will explore the reasons behind bumpy apples, using credible sources and top search results to shed light on this intriguing phenomenon.

Apple Varieties

One of the main factors contributing to bumpy apples is the variety itself. Different apple varieties have different characteristics, including variations in texture and appearance. Some apple varieties naturally develop bumps, ridges, or lenticels (small spots or pores) that are part of their genetic makeup. For example, the famous Granny Smith and Jonathan apple varieties are known to have bumpy surfaces as a normal characteristic.

Environmental Factors

Environmental conditions during the apple’s growth can also affect its appearance. Irregular irrigation patterns, extreme weather fluctuations, or inadequate nutrients in the soil can contribute to the development of bumps on the fruit’s surface. These factors can disrupt normal cell growth and division in the apple, resulting in an uneven texture.

Pests and Diseases

Pests and diseases can have a significant impact on the growth and appearance of apples, contributing to the development of bumps or irregular surfaces. Here’s a more detailed explanation of how pests and diseases can affect apple growth:

  • Apple maggots: Apple maggots (Rhagoletis pomonella) are common pests that can cause bumpy surfaces on apples. Adult apple maggots lay their eggs under the apple skin, and once the eggs hatch, the larvae burrow into the flesh of the fruit, feeding and causing damage. As the larvae grow, they create tunnels and channels within the apple, resulting in raised areas and bumpy textures on the fruit’s surface.
  • Codling moths: Codling moths (Cydia pomonella) are another important pest of apple trees. Codling moth larvae tunnel into the fruit and feed on the apple flesh, creating irregular galleries and channels. This feeding activity can result in bumpy or distorted areas on the apple’s surface.
  • Apple scab: Apple scab (Venturia inaequalis) is a fungal disease that affects apple trees and fruit. It causes dark, scaly lesions on leaves, fruit, and twigs. Severe scab infections can result in rough, corky, or bumpy spots on the apple skin. These raised areas are a result of the fruit’s response to the fungal infection, as it attempts to protect itself by producing additional layers of tissue.
  • Apple mosaic virus: Apple mosaic virus (ApMV) is a viral disease that affects apple trees and can cause various symptoms, including irregular growth patterns on the fruit. Infected apples may have bumpy or distorted surfaces as a result of the virus disrupting normal cell division and growth processes.
  • Bacterial canker: Bacterial canker (Pseudomonas syringae pv. syringae) is a bacterial disease that can affect apple trees and fruit. It causes sunken, cracked lesions on the fruit, which can result in bumpy or uneven surfaces as the affected areas heal and scar.
  • Apple rust diseases: Rust diseases, such as cedar apple rust and quince rust, can affect apple trees and fruit. These fungal diseases produce distinctive, raised, and bumpy structures on the surface of the apple. These structures, known as galls or rust pustules, can give the fruit an irregular appearance.

Proper pest and disease management through Integrated Pest Management (IPM) practices, including regular monitoring, early detection, and appropriate control measures, can help minimize the impact of pests and diseases on apple growth and reduce the incidence of bumpy surfaces.

Chemical Exposure

Chemical exposure can affect apple growth in several ways. When apples are treated with pesticides or other chemicals, improper application or excessive use can disrupt normal growth processes, resulting in irregularities in the appearance of the fruit, including bumps on the surface. Here are some key points to keep in mind:

  • Growth regulation: Chemicals used in apple production, such as growth regulators, can affect the development and growth patterns of the fruit. These regulators are often used to control fruit size, enhance color, or delay ripening. However, if not applied correctly or in the proper amounts, they can cause imbalances in hormone levels, resulting in irregular and bumpy fruit surfaces.
  • Cell division and expansion: Chemical exposure can interfere with the essential processes of cell division and expansion in apple fruit. Pesticides or other chemicals can disrupt the natural signaling pathways and biochemical reactions that regulate cell growth. This disruption can lead to uneven or abnormal cell division, resulting in bumpy or distorted surfaces on the apples.
  • Tissue differentiation: Various tissues form during apple development, including the skin, flesh, and core. Chemical exposure can affect the differentiation of these tissues, causing irregularities in their growth and arrangement. This disruption may manifest as bumps, lumps, or other textural abnormalities on the surface of the fruit.
  • Physiological disorders: Chemical exposure may also contribute to the occurrence of physiological disorders in apples. Physiological disorders are non-infectious abnormalities that affect the internal or external appearance of the fruit. Excessive chemical treatments or improper application can cause disorders such as cork spot, bitter pit, or russeting, which can result in bumpy or rough spots on the apple skin.

It’s important to note that the effects of chemical exposure on apple growth can vary depending on the specific chemicals used, their concentrations, application methods, and timing of application. Appropriate and responsible use of chemicals, following recommended guidelines and regulations, can help minimize any negative effects on apple growth and ensure the production of healthy, visually appealing fruit.

Fruit Development Factors

During the early stages of apple development, irregularities in cell division or uneven growth rates can result in bumpy surfaces. Factors such as inadequate pollination, imbalanced hormone levels, or physical damage to the fruit can contribute to these developmental irregularities.

Can You Eat Apples With Bumps?

When you see apples with bumps, you may wonder if they are safe to eat. In most cases, apples with bumps are perfectly safe to eat. The bumps are usually cosmetic imperfections and do not pose a significant health risk. Many bumpy apples still retain their delicious flavor and nutritional value. It’s important to note that not all bumps are the same. Some bumps are natural and inherent to certain apple varieties, while others can be caused by environmental factors, pests, or disease. If the bumps are harmless and merely cosmetic, you can enjoy the apple by washing it thoroughly, removing any damaged areas, and enjoying the crisp, flavorful flesh.

However, if you suspect that the bumps are the result of pests, disease, or chemical exposure, it’s wise to exercise caution. In such cases, it’s best to consult agricultural experts or local extension services to assess the safety of the apples. They can tell you if the apples are safe to eat or if any precautions should be taken. In general, if the bumps on the apples do not indicate significant damage or the presence of harmful substances, you can safely enjoy them. Remember, appearances can be deceiving, and bumpy apples can still provide a tasty and nutritious eating experience.


In summary, the presence of bumps on apples can be attributed to various factors, including the apple variety itself, environmental conditions, pests and diseases, chemical exposure, and fruit developmental irregularities. By understanding these causes, we can appreciate that bumpy apples are not necessarily a sign of poor quality or safety concerns. Embracing the natural variations in apple appearance can add an element of intrigue and uniqueness to our fruit-eating experience.


Why are my apples bumpy?

There are several reasons why your apples may be bumpy. Here’s a quick list of common causes:

  1. Apple variety: Some apple varieties naturally have bumpy surfaces as a normal characteristic.
  2. Environmental factors: Inconsistent irrigation, extreme weather, or inadequate soil nutrients can all affect apple growth and cause bumpy surfaces.
  3. Pests and Diseases: Pests such as apple maggots or diseases such as apple scab can cause irregularities in the apple surface.
  4. Chemical Exposure: Improper use of pesticides or other chemicals during cultivation can disrupt normal growth processes and cause bumps on the fruit.
  5. Fruit development: Problems during early apple development, such as inadequate pollination or physical damage, can result in bumpy surfaces.

By identifying the specific cause of the bumps, you can take appropriate steps to correct the problem and promote healthier apple growth.

Can you eat apples with bumps?

Apple Scab is a fungus that causes hard brown lesions or bumps to form on the skin. Can you eat the apples affected by Apple Scab? Yes, you can definitely eat unaffected parts of the fruit.

What causes knobby apples?

Aphids: Usually, aphids are considered a pest of the leaves. However, the woolly apple aphid (Eriosoma lanigerum) feeds on the bark of small twigs, around pruning cuts, and on the roots of apple trees. The feeding causes the tree to form knobby galls, which can occur on the twigs and roots.

When should you not eat an apple?

It’s best to discard apples that are soft or show other physical signs of expiration, as moisture content under the skin can indicate contamination (5). You can usually tell whether an apple has started to go bad by examining its appearance. Apples that have gone bad should be discarded.

What are the bumpy apples called?

Hedge apple fruit

Hedge apple fruit

The fruit, like the tree, is unusual; it’s a heavy ball, ranging from 3 to 6 inches in diameter, and it has a tough, wrinkled, or bumpy surface, which turns from dull green in the summer to bright yellow-green in the autumn as the leaves fall.

Why do some apples have a weird texture?

Dry and Mealy Apples

When apple cells age, their cytoplasm and vacuoles lose moisture over time and can no longer reinforce the rigid cell wall. As a result, the cells become deflated and flimsy.

Why are my honeycrisp apples deformed?

Larvae hatching from the eggs feed inside the fruit until they are fully grown. Larval feeding in apples can cause distortion of the fruit. Control: If you are seeing this damage on the fruit, it is already too late to treat.

How do you treat apple gall?

No cure exists for the disease, and it may kill a young apple tree by girdling the stem. A mature apple tree may be able to tolerate crown gall. Carefully inspect apple trees to avoid purchasing a tree infected with crown gall.

Why should we avoid apples at night?

Potential downsides of eating apples before bed

Studies suggest that eating late at night may increase your susceptibility to obesity and cardiometabolic diseases, such as diabetes, high blood pressure, and high cholesterol ( 23 ).

Why do doctors not eat apples?

While the phrase was first coined in 1913, it was based on a Pembrokeshire proverb that originated in 1866. In fact, Notes and Queries magazine was the first to publish the original quote: “Eat an apple on going to bed, and you’ll keep the doctor from earning his bread.”

Why don’t we eat apples at night?

Pectin helps control blood sugar and cholesterol levels, which means you should indulge in the forbidden fruit a lot. But once again, not at night. Why? Because pectin is hard to digest, and since you won’t be exercising after dinner to help your body metabolise it, it can lead to acidity.

Are scabby apples OK to eat?

Scab can cause cosmetic blemishes on the fruit. Fruit with apple scab is still edible.

Is it safe to eat an apple with broken skin?

If your bruised fruit has so much fungal activity that you can see or smell it, don’t eat it. In addition to bruised areas, you should check the area around the fruit’s stem for mold, which is an entry point for opportunistic microbes. Food safety experts have a saying: If in doubt, throw it out.

Can you eat apples with lenticels?

Why the little dots on apples are OK to eat. Don’t worry, those little dots on your apple are supposed to be there. Like all living things, apples need to breathe, and that’s a job left to the tiny speckles, which are called lenticels.

What apples have bumps on the bottom?

Gala and Red Delicious apples have very similar eyes, with a few bumps surrounding the bottom of the apple.

Why do some apples have a weird texture?

Dry and Mealy Apples

When apple cells age, their cytoplasm and vacuoles lose moisture over time and can no longer reinforce the rigid cell wall. As a result, the cells become deflated and flimsy.

What are brown bumps on apples?

A: Known as “russeting,” it is a brownish corky or netlike texture that appears on certain varieties of apples and pears. Russeted patches are not only edible, but they also tend to have a nutty flavor. In apples, russeting typically occurs in heirloom varieties, such as Gravensteins, Pippins, and Jonathans.