styrofoam peanuts for drainage
In reading some past threads on this site I see that there are negative feelings about using styrofoam peanuts in the bottom of containers to allow adequate drainage. I have always used gravel in the bottoms, but using gravel makes the containers heavy. So this past winter (I am AZ so we plant things in the winter here) I planted several containers with geraniums using the peanuts at the bottom. The containers with the peanuts are lighter to move around and I can see no difference in the health or performance of the plants in those containers vs. the ones with gravel.
I would appreciate and specifics as to why the use of the non-biodegradeable peanuts is not a good idea.