I have tomato plants I have grown froom seed in containers on my deck. I have 3 containers. I put one bag of the same kind of organic soil in each container. Four of the 6 plants are doing beautifully. The remaining 2 are not. I just noticed that the soil for those 2 plants has little white mushroom like things growing in it. I bought 2 bags of the soil from 1 Home Depot and the 3rd bag from another Home Depot. What should I do?