How to provide good drainage
I have decided to put two very large pots of oriental lilies in the ground. I potted these lilies several years ago since every place I tried to dig there was hardpan about 8-10 deep. I have good topsoil for most perennials, but am afraid this impenetrable layer of clay will not drain well enough for the lilies.
If I plant them 6" deep they will only have two inches of soil before the roots reach the clay. Is this enough? Should I remove several inches of the clay and put gravel or sand in the bottom? Will this create the "bathtub effect?" I thought I would mix sand and bark chips in the backfill to help with drainage.
I hope you lily lovers can give me some suggestions, Tkx