The white mold It is a disease caused by fungus Sclerotinia sclerotiorum (Lib.) de Bary. This pathogen is widespread throughout the world and affects many species. It is found especially in areas with moderate temperatures and high humidity, such as northern Spain. It appears in many crops causing a significant decrease in the yield and quality of the harvest, especially during the humid summer and autumn.
In this article we are going to tell you how to remove white mold from plants and what you should take into account to do so.
The mushroom Sclerotinia sclerotia is included in the Ascomycete fungi and forms the famous white mold. Their life cycle consists of an asexual stage and a sexual stage with the main function of spreading diseases. In the asexual stage, the sclerotia germinate under conditions of high humidity and moderate temperature, producing a cotton-like mycelium. It usually enters plants through wounds or openings in the soil. The fungus grows on the infected plant and produces new sclerotia, that easily fall to the ground and start the cycle again. Sclerotia are composed of a large number of hyphae that can survive in the soil for several years and is the main mode of disease transmission.
The sexual life cycle also begins with the sclerotia. On them, structures called apothecia develop, which house the asci that contain the ascospores. These are easily blown away by the wind and deposited in different organs of the plant. Ascospores germinate and infection occurs rapidly, and senescent parts of plantslike wilted flowers, are very susceptible. From here, the fungus grows and infects the other organs of the plant and develops a white cotton-like mycelium. Sclerotia form on the mycelium and can easily fall to the ground, starting the cycle all over again.
Why does white mold grow on plants?
Mold is a fungus made up of microorganisms that live on animals or plants, so when it spreads through air, water, or insects, it can grow on soil, food, or other surfaces. To grow and reproduce, mold needs a moist environment and organic matter. Therefore, in your plants, moist, warm and humid conditions, such as overwatering or poorly drained pots, favor their growth. According to gardening experts, indoor plants are more prone to mold than outdoor plants due to ventilation, but this is not the rule.
White mold on plants tends to appear in warm, humid conditions, especially when plants are overcrowded. It is often easiest to identify when it appears on the leaves of our plants, looking like fluffy white spots. In the case of soil, it can also appear as white specks, but it is easy to confuse it with traces of lime or salt.
Lime or salt stains appear due to irrigation because they are components of the water that has accumulated in the soil. Unlike molds, these residues tend to harden, allowing them to be removed. Mold may appear on the soil because it spreads throughout the substratesometimes invading pots and foliage.
A leaf mildew condition, in addition to being identified by the appearance of white spots and soft hairs, may be accompanied by dead leaves and shriveled stems. Plants can die completely if left untreated.
How to remove white mold from plants
Let’s see step by step how to remove white mold from plants:
Get rid of the layer of white mold
The first thing is to isolate the plant, since the mold (its spores) can quickly spread to other pots. In a ventilated area, take the plant out of the pot to assess the problem, and take a look at its roots: if you find soft or rotten roots, cut them off.
Now, with the help of a garden spade or a rake, you need to remove the first 6 to 10 cm of soil, the topmost soil, and replace the plant growth with new soil. This little trick will be enough if the mold does not settle on the plant for a long time. However, if this is not the case and the fungus has managed to reach deeper depths, or resurfaces after a few weeks, we need to replace all the soil in the pots and repot our life partner plants.
For this, it is convenient to use a good substrate or organic compost, especially for the plants, since we will know that the drainage will be good. Just what we need so that the water does not accumulate and the happy mold does not come out again!
One tip is to add perlite or garden gravel, it can lighten the soil and prevent it from compacting, as we said when we talked about the best substrate for cacti and succulents. Either of these two options can improve drainage. We can cover the surface of the pot with a layer of expanded clay balls, that controls moisture and prevents mold from reappearing.
Clean the pot with soap and baking soda
We also need to clean the pots and pans with dish soap (a common cleaner), a bit of baking soda, and water. The grandmothers were right: baking soda is like a light ash that helps to remove mold from pots well.
As is sometimes claimed, baking soda does not attack fungus, but it is a very good dehydrator that removes moisture from surfaces (exactly what fungus loves). Let the pot dry completely before filling it with new soil.
Clean the leaves well
Subsequently, the affected leaves should be washed with water and then dried with kitchen paper, one per leaf to prevent the spread of mold. Also, remove or cut off damaged or dead leaves.
For this cleaning to be more effective, we can use an eco-fungicide, or do it ourselves at home: for this we need a tablespoon of baking soda (for the same reasons that we mentioned before), half a teaspoon of liquid soap, a tablespoon of horticultural oil (as we find it in nurseries or from this link) and half a liter of water. We didn’t skip the oil because, in addition to its antifungal properties, it helps the mixture stick well to fungus.
I hope that with this information you can learn more about how to remove white mold from plants.