Why‌ ‌Is‌ ‌My‌ ‌Soil‌ ‌Turning‌ ‌White‌?

The GardenSpring |

Soil that is turning white can be an indication of a number of issues that could be killing your plants or be a cause for worry.

A number of diseases can cause this effect on the soil and it’s a good idea to find out the answer to Why‌ ‌Is‌ ‌My‌ ‌Soil‌ ‌Turning‌ ‌White‌?. The soil may also turn white due to overwatering or a lack of proper nutrients.

White fluffy stuff on the soil of your plant could be a fungus or mold. If there is an excess of water, poor drainage in the soil, and contamination of the soil itself (such as from a dead insect).

You could get fungus growth on your plant’s surfaces that may even cause it to die.

Why Do Molds Form?

During the rainy season, when it is humid all day and night, indoor humidity can rise above a certain level and mold can form on the soil. Plants love moisture, but if the topsoil is humid and there is no ventilation, mold will also form.

Why‌ ‌Is‌ ‌My‌ ‌Soil‌ ‌Turning‌ ‌White‌?
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Actually, this fungus is a beneficial microorganism called ‘actinomycetes’. It is a  microorganism with characteristics intermediate between mold and bacteria. It decomposes organic matter in the soil, makes it fertile, and secretes various antibiotics.

Mushrooms, the same fungus, for similar example, are good friends to help plants grow healthy. Small pollen contains an ecosystem.

Microorganisms such as fungi and bacteria can help and sometimes harm a child’s growth, but most of the fungi living in healthy soil are beneficial to plants in various ways.

Why‌ ‌Is‌ ‌My‌ ‌Soil‌ ‌Turning‌ ‌White‌?

We all recognize healthy soil with its pure dark brown color and fluffy texture. Over time and as we take care of the plants we have in pots, some whitening may appear on the soil surface.

Is there a disease? The first thing we think about is mold, especially if the pots are indoors that are not well ventilated. Is the plant sick and is bleaching a sign?

What happens when the soil in the pot starts to turn white and is covered with a white layer? The whitening of the soil in the pots of plants mainly occurs in two cases.

The first has to do with the appearance of white mold in the soil due to the development of fungal diseases in the pot. The second reason that creates Mold in the soil of the pot is the excessive accumulation of salts from fertilizers or irrigation water. 

What Causes the Whitening of the Soil in the Pots?

If you keep flowers and plants at home or at work, sometimes we see the soil surface of our pots crack and turn white. As if sprinkled with salt on the ground. Do you know the reason?

Whitening in the Soil Due to Salts and Calcium 

If a white brittle crust appears in the soil of the pot, it is usually due to the excessive accumulation of salts and calcium.

The salts come from the water with which we irrigate, especially in coastal areas. Where the water has a high salt content.

In addition, the salts come from the nutrients present in the soil of the pot and which we add when we use fertilizer. The phenomenon is more intense when we do not have good drainage in the soil of the pot so that the salts are removed with the irrigation water.

Bleaching in the soil due to the accumulation of salts occurs more often. When we water the plants from below by putting water on the saucer or by dipping the pots in a basin of water.

The water rises upwards bringing to the surface salts and calcium that has accumulated in the soil. 

How Can We Avoid the Salts in the Pot?

  • Remove the surface layer of soil 2-3 cm and replace it with new topsoil. 
  • Water the plants with good quality water that does not contain a high concentration of salts. 
  • If the plants on our balcony are covered when it rains, it is better to take out the pots to be watered with rainwater that helps to wash away the salts.
  • Avoid excessive use of chemical fertilizers that can cause gradual accumulation of salts on the soil surface.

Whitening in the Soil Due to the Appearance of Mold 

A small amount of mold can appear in all pots and is not something we should worry about. But if the asparagus begins to cover the entire surface of the soil, then we understand that our planet needs help.

In this case, there is the development of various fungal diseases, such as sclerotia, which can cause significant problems in the plant.

The development of fungal disease is favored in conditions of excessive humidity and poor ventilation in the soil. As well as when we do not have good drainage in the pot.

As a result of which more water is retained than the plant needs. Small mushrooms can also appear in our pot, something that is more common in soils that contain a large percentage of organic matter from manure .or compost. 

How to Deal With the Appearance of Mold in the Pot?  

  •  Remove the plant from the pot and remove the old soil. 
  • Shake the soil from the roots of the plant and cut the peripheral roots, removing part of the soil. 
  • Wash the pot with warm water to remove possible residues of the disease.
  • Plant again, using high-quality perlite-containing topsoil to ensure better aeration and drainage conditions. 
  • We ensure better ventilation conditions for the plant and follow the tips for proper watering and healthy plants.
Salt Washing Plants

The plant absorbs the materials it needs and the substances that are not absorbed accumulate in the soil around the plant.

This accumulation of minerals can damage the plant. Fortunately, there are very simple ways to get rid of this condition, known as leaching.

Potted plants should be washed regularly to keep the soil clean. Click to see the salt washing method.

Potting Soil

If you do not use suitable soil with a suitable salinity range and pH, the soil surface will gradually turn white with watering the plant. Use a mixture of peat moss and coco peat instead of miscellaneous soils.

Peat moss is pest free and is very suitable for flowers and plants due to its soil fertilizer. Cocopeat also creates a suitable substrate for more rooting and better plant growth due to the porosity it creates in the soil texture.

Type of Water

You might think that plants can be irrigated with any kind of water. But this idea is wrong. Plants, like us humans, need good quality water. Some plants are also sensitive to water temperature.

Another reason for the whitening of the soil surface may be the salinity of the water.

What Can We Do to Whiten the Soil Surface?

  • Replace the potting soil. Use a combination of coco peat + peat moss.
  • Reduce watering the plant.
  • Use humic acid fertilizer every 20 days.
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The Botany Girl

Mold Prevention & Treatment

Although the fungus on the soil is not harmful to plants, there are some who are concerned that it is not aesthetically pleasing and may harm pets or children. 

To prevent mold growth during the rainy season, first of all, you should check the dryness of the soil frequently. In summer, when moisture evaporates quickly.

You need to water more often than usual, but in the rainy season, conversely, you should increase the watering cycle. Turn on a dehumidifier indoors to control the humidity or move it to a place with good ventilation. 

However, if you put it close to the air conditioner, it may be damaged by sudden temperature changes, so please avoid it.

If mold has already grown, use an unused spoon to slightly remove the moldy top, and fill in the empty areas with new soil.

If mold develops clean it under running water. Dry it in the sun, and cover it again. However, Masato acts as a barrier to moisture evaporation, so if you are in a humid environment.

You can wait until autumn to use it. In case of severe mold growth, mix 70ml of hydrogen peroxide with 500ml of water and spray it to get rid of it.

Please note that spraying too often can kill all other beneficial bacteria in the soil as well.


White Mold on top of soil on houseplants and is it Harmful ? (2017, December 27). YouTube. https://www.youtube.com/watch?v=uaRtzuuYYdE

Z. (2022, February 25). How to Get Rid of White, Fuzzy, Moldy Potting Soil. Dengarden. https://dengarden.com/gardening/Moldy-Potting-Soil



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