You’ve probably noticed white spots on parsley leaves if you are a gardener. White spots on parsley leaves are quite common in this low-maintenance herb.

Even such a straightforward vegetable to grow as parsley (botanical name Petroselinum crispum) has its challenges. White spots and even brown spots can appear on parsley leaves at times. If it happens to your parsleys in your vegetable garden, you want to know the causes and treatment.

I researched to help you deal with white spots on parsley leaves.

What is White Spot Fungus on parsley leaves?

A species of Cercospora causes white spot fungus on parsley leaves. And it has become more common in recent years.

White spot on parsley and various leafy vegetables is one of several cruciferous fungal issues. White spot fungus also goes by the name “frog eye.”

Look for circular to irregular spots on parsley leaves ranging from ¼ to ½ inch (6 mm. to 1 cm.). These white spots are scattered across the leaf. The spot starts with a light tan color and dry spots and soon turns to papery white lesions on the leaf surrounded by a yellow or pale green halo.

The white spots grow and merge. Chlorophyll production decreases as the green area on the leaves disappear, and the parsley leaves soon begin to yellow and die. White spots on leafy vegetables can destroy a crop of seedlings or severely deform them.

Older parsley plants can survive the loss of their outer leaves. Unfortunately, cruciferous fungal diseases, such as the white spot fungus, are passed along from previously infected surrounding weeds or plants.

They are borne on the wind and begin in cool temperatures of 55 to 65 degrees F. (10-18 C.) and rainy weather of early spring, exactly when cruciferous vegetables should be planted. White spot becomes more severe as the temperatures rise.

What causes white spots on parsley leaves?

Several things can cause Whites spots on parsley leaves. The good news is you can treat white spots if you follow this guide.

Does poor soil cause white spots on parsley leaves?

Poor soil can result in white spots on parsley leaves. Low-quality soil is the reason behind nutrient deficiency, causing white spots in parsley leaves. If you want to avoid white spots, this vegetable requires nutrient-rich and moist soil with decent soil drainage.

If the soil is of poor quality with insufficient moisture, then this vegetable cannot thrive. To avoid or get rid of the white spots, you need to make sure the soil provides all the required nutrients for your parsley.

Does the lack of sunlight cause white spots on parsley leaves?

The lack of sunlight can cause white spots on parsley leaves. Not enough sunlight is often the reason for white spots not just on parsley leaves but also on other plants’ leaves, like sage, mint, and basil.

If you want to avoid white spots, this plant requires sunlight. Without enough sunlight, this herb cannot thrive. To avoid the white spots on your parsley leaves, make sure to plant them in an area with full sun. But, parsley can tolerate some shade.

For indoor gardeners, make sure you position your parsley in a sunny location. But, it may require fluorescent lamps. To make sure your parsley gets enough light, keep the fluorescent lamps no more than four inches from the tops of the vegetables.

Does powdery mildew cause white spots on parsley leaves?

Powdery mildew can cause white spots on parsley leaves. It’s a common reason for white spots on parsley leaves.

This is one of the most widely spread plant diseases, resulting in white spots or patches on parsley leaves. Powdery mildew is most severe in dry, warm climates.

Unfortunately, parsley isn’t particularly resistant to this fungi. You can observe talcum-powder-like growth on the upper sides of parsley leaves. But, it may also affect the bottom sides of parsley leaves.

Do bacterial diseases cause white spots on parsley leaves?

Bacterial diseases can cause white spots on parsley leaves. If you grow parsley, you should know that contaminated plant materials, irrigation water, and equipment can introduce harmful bacteria to your garden.

You can prevent bacterial diseases by ensuring that you only bring disease-free plants and equipment into your vegetable garden. Another way to control bacterial diseases is by removing any infected parsley and plants from your garden.

Also, practice crop rotation to avoid the buildup of the disease with seasons.

Does Stemphylium cause white spots on parsley leaves?

Stemphylium is another fungal disease that can cause white spots on parsley leaves. This disease is seen as small spots which gradually grow larger with time and can turn dark brown. Stemphylium generally attacks older parsley leaves.

Do Spots Septoria cause white spots on parsley leaves?

Spots Septoria can cause white spots on parsley leaves. Parsley gardeners should be aware of the symptoms of Septoria leaf spot.

Parsley is susceptible to Septoria leaf spot in the summer. The first leaves that are affected are typically toward the parsley’s bottom.

How to eliminate white spots and other fungal diseases from parsley leaves?

One of the best ways to eliminate white spots and other fungal diseases from parsley leaves is installing a drip irrigation system. Unfortunately, when it comes to these diseases, the splashing water overhead is the culprit. A drip irrigation system will help you get rid of fungal diseases and white spots from parsley leaves.

Another way to get rid of white spots is to ensure your parsley plants get enough space for air circulation. The air circulation allows the parsleys to dry after rains and watering.

Garden sanitation is critical for treating white spots on parsley leaves. Unfortunately, fungal spores can overwinter on any organic matter left in your vegetable garden. Regularly clean your garden equipment and wash your hands after inspecting contaminated parsleys.

You should clear away and dispose of all garden debris from your vegetable garden at the end of the growing season. And if you have the garden equipment, plow under crop debris after harvest. This will allow organic matter to quickly decay.

If your parsleys get enough sunlight, it’s less likely they develop white spots on their leaves. Indoor gardeners should keep their parsleys near a window to ensure they get enough sunlight and air.

Crop rotation is another effective way to control white spots on parsley leaves. Plant your parsleys in different areas each season. Leave a two-year span before planting parsleys in the same spot again.

As soon as you notice white spots, spray a natural fungicide to control the problem.

So, these tips should help you avoid and eliminate white spots in your parsley next season.

How to treat white spots on parsley leaves?

Natural remedies are safer to treat white spots on parsley leaves than toxic ones. Indeed, natural remedies can still be toxic, so always use remedies to get rid of white spots with care.

As we all know, chemical-based fertilizers and fungicides can be very toxic to our health. There is no doubt that chemical fertilizers can be effective, but they are more harmful to humans and animals.

Here, we list some natural remedies you could try for treating white spots on parsley leaves. Some of these treatments may be more effective than others, but why not if you want to experiment?

Of course, you should always protect yourself with gloves and a mask before treating any of your plants.

Is neem oil effective in getting rid of white spots on parsley leaves?

Neem oil is a natural fungicide, excellent for eliminating white spots on parsley leaves. It’s a biodegradable fungicide effective for the treatment of bacterial infections.

As an added benefit, neem oil is also safe for humans and pets. The best method is to spray neem oil on the infected parsley leaves. Spray on a sunny day. For best results, use neem oil every 14-days.

Can I treat white spots on parsley leaves with sulfur?

Sulfur is a natural remedy for white spots on parsley leaves and other fungal infections. If used correctly, sulfur can stop white spots from spreading.

Follow the manufacturer’s instructions when you use it. And avoid using it when the temperature is above 85 F. Even though sulfur is nontoxic to fish, bees, and birds and relatively nontoxic to humans, you should wear a respirator during application.

Avoid skin and eye exposure. Don’t use sulfur for at least 30-days after applying an oil spray.

Can I treat white spots on parsley leaves with baking soda spray?

Baking soda has countless household uses. Although it’s one of the most versatile household items, it’s not the most effective for treating white spots on parsley leaves.

You are better off using baking soda for cleaning and cooking. But, if you want to try anyway, you can try treating white spots on parsley. It is a natural and nontoxic fungicide that some people claim to work.

Keep in mind that if you try to use baking soda spray to eliminate white spots on parsley leaves, it may result in a sodium build-up in the soil. And sodium can harm the roots of your parsleys and other plants.

As long as you understand that baking soda may negatively affect soil quality, at least it’s safe for your health. For this, mix 1/2 cup of baking soda with two cups of tap water. Mix well and fill the solution in a spray bottle. And spray infected leaves with the mixture.

Can I treat white spots on parsley leaves with horticultural oil and baking soda?

Here is a variation on the baking soda treatment for white spots. Adding horticultural oils can make the baking soda mixture more effective in controlling some types of fungi, such as white spots.

If you don’t want to purchase the mixture, you can combine your natural petroleum-based horticultural oils with baking soda fungicide.

In a gallon of water, mix two tablespoons of baking soda with four tablespoons of horticultural oil. Then, fill a spray bottle with the fungicide.

When you see white spots or powdery mildew signs, spray the mixture on the parsley leaves and stems. Keep spraying the leaves until they’re dripping wet.

During the summer months, you can use it every two weeks. Avoid using horticultural oils on young shoots or open flowers. You should also avoid spraying if the temperature is over 90 F or below 32 F or if the parsley is wet or rain is in the forecast.

Can I use copper fungicides and soaps to treat white spots on parsley leaves?

Copper-based fungicides are manufactured as ready-to-use formulations, dusts, wettable powders, and liquid concentrates. It is effective against downy mildew, powdery mildew or white spots, and various other fungal diseases.

Before using the product, read and follow the manufacturer’s directions on the package label for timing and safety precautions, dosages, and dilution recommendations.

Even though copper-based products are toxic to people, pets, and aquatic organisms, including fish, they are considered safe for birds and bees. Unfortunately, over time, copper can accumulate in the soil to levels that may damage the roots of your parsleys.

Is it safe to eat parsley with white spots?

Avoid eating parsley using the leaves if you notice white spots or other fungal or bacterial infections.

Conclusion

Parsley is a sensitive plant, and improper care could result in white spots on parsley leaves. But where do white spots come from on parsley leaves?

The white spots on parsley leaves are caused by fungi such as powdery mildew and downy mildew. Both of these fungal infections result in white spots on parsley leaves.

In addition to powdery mildew and downy mildew, white spots can be caused by the following:

  • Bacterial infection – These microscopic organisms rapidly divide in cold, humid conditions. A bacterial infection can inhibit growth.
  • PestsPests such as thrips, whitefly, and aphids attack parsley. As a result, white spots appear on parsley leaves.
  • Celery mosaic virus – This virus produces white circles that may look like white spots on parsley leaves. Celery mosaic virus could severely affect the development of your parsley.
  • Saline soil and hard water – Water that includes magnesium sulfates, sodium chloride, calcium bicarbonate, and magnesium carbonates could cause white chalky deposits on parsley leaves. The white deposits form as the water evaporates, and the high salt content remains on the parsley leaves.