Q.strange white fluffy stuff
I have grown grass in a pot, and now it is about 3 inches tall. But I have noticed some kind of white fluffy stuff on the surface. What is it? Is it poisonous to plants?
This is generally a fungus mold and may be due to soil that is not sterilized.
Make sure you use a good quality potting soil for container plantings.
You also can have fungus and mold issues if the plant does not receive good air circulation and or too much moisture.
Most types of fungus like this will not kill the plant, but you can make sure it does not spread or continue.
Increase the light and even place a small fan in the area.