This past weekend I transplanted a few clumps of "black" bearded irises in my garden. The first time I planted iris rhizomes I thought they were planted similar to canna rhizomes and planted them too deep in the soil. A couple of clumps of iris rhizomes never bloomed and some bloomed only sporadically over the next few years. While reading a garden book one day I learned that the reason for the poor flower production was probably due to planting the rhizomes too deep.