An intriguing Iris relative from higher elevations in South Africa which has narrow vertical foliage and dark yellow very Iris-like flowers.  This has proven to be nicely hardy for us here and may well be hardy to Zone 6 especially with mulch.  This provides that important  vertical element in your design scheme.

Love Moraea and a lot of them are winter-growing and too tender for us but this is one that is summer growing and flowering which fits right into the program!  Narrow green leaves with a slight tunic at the base, not as flamboyantly netted as in M. alticola.  Lovely yellow Iris-like flowers come in succession on stems above the leaves.