Question
Hi. I have 4 different plants in the same area- Goldfish plant, Mother-in law Tongue plant,Jade and Lipstick plant. The plants themselves look normal, but there is unpleasant smell coming from the soil surface. There also white substance on it. I took one of the plants out of the pot and didn't found smell or any sign for disease there. Can You  tell me what is it and how to treat the problem?
Plants in the other locations in the house don't have  that problem.

Answer
Hi Alla, It's probably just from fungus that is growing in the soil.  I suspect it will not hurt your plants, it's just growing on the decomposing organic matter in your soil. Since it's isolated to just these plants, it probably came in on one and has spread to the others. You might mix a tablespoon of deodorizing cat litter into the soil surface or try spraying the surface of the soil with Febreeze.  Avoid getting it on the plant.  The enzymes in Febreeze do a good job of neutralizing odor.  You may have to do this occasionally to control it.  Jim