Hello! I am very new to gardening having just moved into my first home (not apartment). I wanted to put some potted plants on my stoop and so bought a variety of plants which can live in the shade, some potting soil and ceramic pots and made a go of it. I thought I did a nice job until someone asked "did you put a layer of rocks at the bottom of your pots?" Uh oh! I didn't and each pot does have a drain hole. Should I re-pot them with a layer of rocks at the bottom (under the soil)? Apparently this keep the roots from rotting?