What Causes Mold On Leather Shoes?

As per EPA, mold spreads from invisibly tiny spores. Mold grows when mold spores land on damp surfaces.

Mold does more harm than discoloring and damaging leather shoes.

According to the CDC, mold exposure may cause a stuffy nose, wheezing, and red or irritated eyes or skin. Some people who are allergic to molds, such as those with asthma, can experience more severe responses.

This article will elaborate on the causes of mold on leather shoes. Knowing what causes mold to grow on leather shoes can help you take preventive measures to protect your footwear investment and health.

Causes of Mold on Leather Shoes

If you’ve ever found mold on your leather shoes, you know how frustrating it can be. Mold can cause the leather to deteriorate and make your shoes look old and worn.

Tests have shown that mold growth on leather increases its stiffness, reduces tensile strength, decreases stretchability at the breaking point, and weakens the leather’s grain surface.

In short, mold on leather shoes is terrible.

But what causes mold to grow on leather shoes in the first place?

There are a few causes of blighty leather shoes.


Mold loves wet and moist surfaces. When mold spores land on a receptive surface that is wet or even moist, they latch on. As per FEMA, under ideal conditions, spores can germinate within 24 to 48 hours.

Spore grows into mold in presence of humidity

Leather is a porous material. If your leather shoes are constantly exposed to moisture, it’s more likely that mold will grow.

Unfortunately, it can take mold up to 21 days to become visible. So, if you live in a hot and humid climate or often wear your shoes in the rain, mold can start to grow without you even realizing it. Follow this guide for taking care of wet or damp leather shoes.


Our feet are sweat factories. As per UC San Diego, each foot has 125,000 sweat glands. The soles of the feet have more glands per square centimeter than any other portion of the body. On average, your feet produce approximately half a pint of sweat daily.

Leather being a naturally porous material, can absorb sweat easily. Leather shoes damp with sweat are a perfect habitat for mold and other fungi.

Feet have the most dense sweat glands


While mold thrives on humidity, spores can survive dry conditions. Spores can hitch a ride on dirt to reach your leather shoes.

Nubuck and suede leather shoes are dirt magnets which makes them susceptible to spores in humid and sweaty conditions.

Humidity & Temperature

The ideal temperature for mold growth is 77° F and 86° F. But mold can still grow outside this temperature range if the relative humidity is more than 70%

If you live in a hot and humid climate or your home has high humidity levels, mold can start to grow on your leather shoes.

Mold growth at different temperatures and relative humidities

Improper Storage

Leather shoes must be stored properly to prevent mold growth. The best way to store leather shoes is a cool, dry place with good air circulation. Leather shoes should not be stored in plastic bags as this can trap moisture and cause mold to grow.

If you are regularly wearing a pair, you should not worry about storage. Just make sure to clean and dry leather shoes thoroughly after each use.

If you are storing your leather shoes for a long time, you should clean and condition them before putting them away. Consider using cedar balls, shoe trees, or silica gel bags to help absorb moisture in humid climates. Learn more about this topic with our guide on storing leather for a long time.

Lack of Care

Leather shoes require regular care to prevent mold growth. If you neglect your leather shoes, they are more likely to develop mold.

Leather shoes should be cleaned after every use. Leather shoes should be conditioned at least once a month.

If you live in a humid climate or your leather shoes are regularly exposed to moisture, you should dry them properly.

Conditioning leather shoes help to keep the leather supple and prevents mold growth.


Leather shoes that are not worn regularly are more likely to develop mold. Shoes in disuse don’t get TLC providing mold with an opportunity to grow.

If you have a pair of leather shoes that you only occasionally wear, clean and condition them before storing them away.

If you don’t plan on wearing your leather shoes for a while, consider using cedar balls, shoe trees, or silica gel bags to help absorb moisture.


Mold loves darkness. Mold is more likely to grow if you store your leather shoes in a dark closet or box. Unless you store them for an extended period, let your leather boots soak up the sun regularly.

Aggravating Conditions

Rain and flooding are apparent mold generators. However, other conditions like leaks, mold-infected AC ducts, and damp walls and floors can also cause mold growth on your leather shoes.

Is Mold on Leather Shoes Dangerous?

Yes, mold on leather shoes can pose health risks. Mold produces allergens that can cause respiratory problems, skin irritation, and other allergic reactions. Mold can also cause shoes to deteriorate and fall apart.

If you think your leather shoes have mold, it’s crucial to take action quickly. The longer mold is allowed to grow, the harder it will be to remove and the greater the risk of health problems.

How to Remove Mold from Leather Shoes

Wearing moldy leather shoes can cause several health problems, including skin irritation, allergic reactions, and respiratory problems. If you think your shoes might be harboring mold, it’s essential to clean them as soon as possible.

The best way to remove mold from leather shoes is to use a mixture of vinegar and water. Alcohol can also be used to kill mold. Check out our guide on how to clean mold on leather shoes. If you have mold on the inside of your leather shoes, this article will come in handy.


Mold can grow on leather shoes for many reasons, including improper storage, lack of care, disuse, darkness, and aggravating conditions.

Blighted leather can pose health risks, and it’s essential to take action quickly if you think your shoes might be moldy.

Mold can be a big problem for leather shoes. It is essential to take mold seriously and act when it starts to grow on your shoes, as the longer mold grows, the harder it will be to remove.

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