Unlike those of us who've caught the iris virus, the everyday gardener wants more out of their plants than a single season of bloom. Rebloomers can fill this need with additional flowers but for multiple seasons of interest and good structure in a mixed border interesting foliage is a necessity. Gardeners have always appreciated the structure of the sword-like fans of leaves of a bearded iris, but many do not know that iris foliage can provide dramatic color as well. Here are just a few of the varieties I grow that are pretty in almost any season.
First up is bearded iris 'Argentea' (Goos & Koenemann, 1906). A form of I. pallida but featuring very bold white stripes up the leaf blades. The flower is the same classic pallida bloom with the heavy grape scent but the added interest of the foliage keeps this an attraction all thru the growing season. 'Zebra' is a similar variety but with bright golden yellow stripes instead of white.
A more modern variety with lovely foliage is the Miniature Tall Bearded 'Madam President' (Thurman, 1998), each spring it has started off with lovely light bright yellow-green foliage which persists until summer heat and sun sends it darkening to a normal tone. It glows in even the lowest light.
Another iris with excellent coloration is the species cross 'Gerald Darby' (Coe for Darby, 1967). The early spring foliage has some of the darkest purple-based foliage (PBF) of any iris I've seen. The color show continues as the deep purple, almost black, bloom stalks rise up and bear lovely violet-blue flowers, followed by seed pods that float like green balloons over the foliage thru the summer. Later leaves are less intensely colored but are still lovely.
Many other species of iris are known to have varigated variants as well. I've seen versions of I. pseudacorus, I. foetidissima, I. ensata, and I. japonica with lovely white or yellow striped foliage, and have seen the glowing yellow-green effect on a few siberians. PBF, of course, is very common in the bearded group and some cultivars show it heavily - often even extending to the spathes when in bud. I've enjoyed following Thomas Silver's posts on Iris-Photos about his progress breeding for PBF, purple leaf margins and purple bracts. I think his work will bring us many beautiful plants worthy of our gardens in the future.
So the next time one of your gardening friends dismisses the iris for its single season of interest, remind them that this great genus' colorful and structural foliage can bring so much more to the garden than a fleeting fabulous flower.