This is a common problem that any amateur gardener encounters at some point: the dusty-looking mold on the soil of houseplants. First, keep calm! Those dusty-looking deposits are not necessarily caused by mold, as many tend to believe.
When you water your plants, especially when you put water in the pot’s plate, salt and lime in the fertilizer reach the soil’s surface. With time, they remain on the soil even if you water the soil directly from the top. Residues can be recognized because of their crumbly and dry texture. These dusty-looking deposits appear after water and nutrients were absorbed by the plant (salt and lime being left behind). If you want to restore the soil’s natural look, just remove the dusty-looking layer and add fresh soil.
On the other hand, if the deposits are fluffy and white with a strong odor of mold, act quickly. Mold is not only unsightly, but it can put your plant’s health in danger.
Less is more
A certain amount of mold can be found in every pot – in small quantities, along with insects and bacteria they naturally decompose the organic material and convert it into fertilizer. However, if the mold expands, it is the result of improper care of the plant. Excess watering favors the formation of mold.
Also, if you use soil with a high content of compost, excess watering will encourage mildew and fungi formation. Substances contained in compost favors reproduction of mold. In this case, repoting in fresh soil is recommended.
When cleaning the plant remove as much of the affected soil. Remove the affected soil off the plant roots. You can reduce the plant roots to stimulate growth. The rule is to reduce the root to a third of its previous size.
Do not forget to properly clean the pot before repoting because spores can remain on the pot’s walls. It is advisable to clean the bowl with warm water and vinegar-based detergent. Finally, rinse the pot with cold clean water. In order to prevent water leakage you can cover the pot holes or you can mix the soil with coarse sand or gravel. Make sure there is no moldy compost in the soil.
How to prevent mold
You can prevent mold recurrence by watering the soil only when needed. The occasional aeration of the soil can also be a solution. Thus, the soil and plant roots remain properly aerated. Do not water your plants too often – only moderately water them when needed. Keep in mind that plants need less water in low light months (October to March) compared to the summer months. Add fertilizer as directed on the package. Remove the fallen leaves and dried flowers because they favor the occurrence of gray mold. You can use soil rich in minerals, it is less prone to mold.
Watering through a plate is the best way to prevent mold occurrence. Pour water into the saucer and remove the excess after half an hour. If water has been fully absorbed, add more water to the plate and repeat the process.
Image Credits: Gardening Stackexchange