What Is The White Stuff That Keeps Growing In My Potting Soil In My Greenhouse?

What is the white stuff that keeps growing in my potting soil in my greenhouse? There could be several things that might happen in the greenhouse, including elements that may be found on plants. Here are the details and how you can address this problem.

What Is The White Mold On My Soil?

The white mold or the white element you see growing on the surface of the potting soil could be a saprophytic fungus and is usually harmless. Though the fungus does seem to damage your plant, having this is unusual and might tell you that there are problems with your crops being cultivated in the greenhouse. 

What Is The White Stuff That Keeps Growing In My Potting Soil In My Greenhouse

Among the causes of the fungus include overwatering the plant, insufficient drainage, contaminated potting soil, and more. They feed on decaying organisms in your soggy soil. 

They may also be white mold that thrives on the soil of your potted plants. These are usually because of insufficient drainage, and poor circulation of air, causing damp and humid environments. These are the ideal environment for the white mold to grow. 

What To Do With This

What is the white stuff that keeps growing in my potting soil in my greenhouse, and would you be able to get rid of it? Definitely. 

Here are the steps that you may want to follow to address the ongoing matter:

  • Remove sick plants. Once the garden is infected, you cannot save the plants when it is too late. However, you can prevent this. What you can do is to dig up the sick ones, throw them in the trash other than the compost pile, so the fungi will not spread. Clean up the debris in the garden right at the end of the season. You may also cut the perennials, pull up your annuals, and go rake up the leaves as you haul them out. This is because fungus may feed on your dead plants when winter arrives.


  • Commit to crop rotation. Crops that are found in various areas of the garden are an arrangement crucial in letting you avoid these instances. What you can do is to move the tomatoes to where you may have the herbs or the marigolds, or where you have the potatoes. If your garden is not huge for this, avoid planting anything in the garden for about a year and move the tomatoes to where the fungus cannot thrive. You may plant in containers.


  • Have you disease-resistant crops. You may cultivate herbs and veggies that are bred to resist the common diseases borne in soil. 


  • Have a fungicide ready. A fungicide with your greenhouse plants will get rid of the white stuff as they defend the plantation from such elements.

How Do You Kill Fungus In Soil?

Dealing with the fungus is gone, but completely removing them is another point of discussion. It is essential to deal with this early on. 

Get away from the trouble and the possibility of wasting your time and effort cultivating the plants because, once the fungus thrives, the plants may not grow beautifully. If your pots, raised beds, and containers have the pathogen elements in the soil, immediately throw away the plant as well as the soil, and plant more new ones.

Unsure of the kind of fungus

If you are uncertain about the type of fungus that has been messing with your greenhouse soil, what you can do is this. First, take a sample with your local office to test your soil. The office could be part of the network of universities, federal and state governments that collaborate to instruct people about better gardens, among many other stuff.

Does Cinnamon Kill Mold In Soil?

Cinnamon may be able to help remove or completely kill the soil in the mold. Scooping out the fungus physically, including the immediate topsoil layer or disposing of it will address most of the problems. If you are sensitive to allergens or have breathing challenges, it is essential that you go ahead and wear your mask. 

Next up, you must be able to sprinkle fine, even layers of ground cinnamon over the top layer of the soil. This is because cinnamon works as a very effective fungicide that can kill any remaining fungus. 

Make sure that you let the topsoil completely dry out before having to water this again, and preferably only water from below the area directly with the reservoir of the self-watering planter. Once the fungus has been cleared up, there should be no need to keep applying the ground cinnamon right into the soil. This shall just kill other forms of helpful fungus in your garden soil.


What is the white stuff that keeps growing in my potting soil in my greenhouse? Seeing fungus in the soil is common in potting soil and mixture, and aside from overwatering instances, they tend to have a huge amount of bark or wood chip present. The fungus usually feeds on them, as well as other decaying organic matter.

Overwatering poses issues with the soil, especially when the plants are grown indoors. In these areas, the soil receives limited sunlight, and this means the top layer of the soil cannot dry out as it stays overly wet. The fungus can and will thrive in these scenarios. 


Leave a Comment