Dre Campbell Farm
8 Natural Ways to Treat and Prevent Potato Scab

This post may contain affiliate links. Click here to view our affiliate disclosure

8 Natural Ways to Treat and Prevent Potato Scab

Have you noticed those ugly scabs forming on your potatoes? Potato scab is a disease that causes raised, corky lesions on potato tubers. If not controlled, it can lead to significant economic losses.

The good news is that there are some natural ways you can treat and prevent potato scab in your garden. Before the problem gets out of hand, take action now.

Symptoms of Potato Scab

The main signs your spuds have scabs are spots, pits, and scaly patches on the potato skin [1]. These spots can range from slightly sunken, scaly areas to deep pits. The scabs themselves are usually tan to brown in color.

As the spots get bigger, they become raised and rough. Badly infected potatoes develop a scabby, crusty appearance.

Scabs on potatoes don’t go deep, so you can eat the potatoes after peeling. The inside is fine.

Affected Crops

Certain varieties of potatoes are less prone to developing scab than others. Varieties like Russet Burbank, Norland, and Superior tend to be less susceptible.

Potatoes with thin skin tend to be affected more. Other root vegetables, such as parsnips, beets, turnips, rutabaga, carrots, and radish, can also suffer from potato scab disease.

How to Get Rid of Potato Scab Naturally

By taking simple precautions, you can prevent this disease and grow flawless potatoes in your garden. Staying ahead of the problem is key, so start planning now for your next potato crop.

1. Crop Rotation

Crop rotation is one of the most effective ways to prevent potato scab organically. Every few years, rotate your potato crop to a different area of your garden.

Potatoes and other plants in the nightshade family can harbor the fungus that causes powdery scab, so avoid planting tomatoes, peppers, or eggplants in that area as well.

Instead, plant crops like beans, broccoli, cabbage, carrots, cucumbers, lettuce, spinach, or Swiss chard the year after potatoes. These unrelated plants will not host the scab fungus. This helps to eliminate it from the soil before you plant potatoes again.

2. Do Not Overwater

When soil is constantly soggy, it creates the perfect environment for powdery scab to thrive.

Overwatering your potato plants can also lead to misshapen tubers. Therefore, properly manage moisture levels in the soil through controlled watering.

3. Till in a Cover Crop

Planting a cover crop, like mustard, before potatoes can help prevent common scab. As the cover crop grows, it acts as a biofumigant. This creates unfavorable conditions for the bacteria that cause the condition.

When the cover crop is tilled into the soil, it also adds organic matter that feeds the beneficial microbes in the soil. These good bacteria help create a natural defense against various pathogens, thus helping to reduce infection.

4. Keep the Soil Moist During Tuber Formation

Keeping the soil consistently moist is critical once the potato plants start forming tubers.

A high level of soil moisture encourages the growth of bacteria, which may crowd out S. Scabies on the surface of potatoes.

5. Keep the Soil Slightly Acidic

Keep the soil slightly acidic, around 5.5 to 6.5 pH. Potatoes prefer slightly acidic soil. Besides, the ideal soil conditions for potato scab are dry, alkaline soils.

You can test your soil’s pH with an inexpensive soil pH tester. If it’s too alkaline, add some gardening sulfur according to the package directions.

Some other natural ways to lower the pH and increase soil acidity include adding compost or peat moss to the soil.

The slight acidity creates an environment that is less favorable for the disease.

6. Keep the Planting Area Free of Invasive Weeds

It’s also important to keep your planting area clear of invasive weeds that can be hosts for potato scab.

Weeds may also compete with your potato plants for water, nutrients, and space. These plants also give shelter to pests like aphids, leafhoppers, and flea beetles. The pests may damage your potato plants.

Moreover, removing weeds regularly will promote better growth and yield in your crop. Therefore, stay on top of weeding, especially early in the growing season.

7. Molasses

Blackstrap molasses contains fatty acids that destroy pathogens that cause scab of potato. It is believed that the molasses will encourage the growth of beneficial bacteria and help them outcompete scab.

To use molasses as a preventative treatment, mix 1 cup of molasses with 5 gallons of water. When planting the potatoes, sprinkle this homemade solution on the soil under them.

Repeat this process a few more times during their growth.

Moreover, you can use molasses as a plant fertilizer. It can be incredibly beneficial for growing healthy plants. It also helps to keep pests at bay.

8. Cueva Fungicide

This is an organic copper-based fungicide that can help prevent and treat potato scab.

Cueva Fungicide Concentrate works in two different ways. First, it helps the copper (the active ingredient) get inside the fungi or bacteria cells. Copper will destroy the pathogenic cell once it has entered. This can lead to fatal cell leakage.

Second, it spreads the material over the surface of the plants.

This helps to protect plants against further damage or possible re-infection by creating an environment hostile to the disease.


So there you have it: some of the best natural ways to prevent and treat potato scabs in your garden.

The key is to keep your soil healthy and balanced and avoid overwatering. Also, rotate where you plant your potatoes each year and consider growing scab-resistant varieties.

Give some of these home remedies and natural methods a try!

Image via researchgate.net

Sasha Brown

Sasha Brown is a blogger and lover of all things natural.

Add comment

Organic pest control

DIY Pest Control