Mold in my gritty?
So I was removing some stakes I had used for transplant plant support and when I pulled them out they all had what appeared to be mold on them. This only happened in one section of a planter box filled with gritty.
Any idea what this is (mold?). Is it damaging to the plants? Should I retransplant with fresh gritty?
Note this window container is on a north facing window and gets no direct light. I also have about 25 containers in the gritty mix now and this is the only one I have seen it in.
Here are pics: