In the south I plant where the rhizome is at least half out of the soil if not more. From what you said they are getting enough sun. How long is several years, Sundra? Are they growing with other plants that get fertilized? Many fertilizers that plants need are high in nitrogen. If irises receive a lot of nitrogen they will grow wonderful fans with little or no bloom. If you re-planted them last fall they may have taken this year to adjust and become established. Many irises do this and will bloom great the following year if the change has given them better growing conditions. You may have wonderful blooms next spring.
BTW, welcome to the irises forum!