We use a lot of iris in our garden design, and no wonder. It’s a magnificently versatile genus. Some like it hot and dry, while others are perfect at the water’s edge. And—true to its namesake, the rainbow goddess Iris—it grows in a host of colors. Here are our two favorite, garden-ready species.
Iris germanica (Bearded Iris)
Bearded (or German) iris boasts ruffled, bearded flowers above pointy, blue-green stalks. It thrives in hot, dry, lean conditions; it can even grow in gravel. This species blooms in late spring and early summer, although new, reblooming varieties may also make an encore late in the summer or in early fall.
These ruffly beauties grow from rhizomes, which are bulgy, root-like stems that grow sideways. When planting, always leave half the rhizome uncovered; burying it can cause the rhizomes to rot.
You can find bearded iris in tones from pastel pinks, peaches, yellows to midnight purples and burgundies. Mix it into your full-sun cottage border, where its sword-like leaves add some vertical interest, or plant it in a rocky border.
Iris sibirica (Siberian Iris)
Siberian iris has slender, grass-like leaves and a fluer-di-lis flower that blooms in May and June in Indiana. While most cultivars are blue or purple, you can also find yellow and white varieties.
This is the most versatile of the irises, taking full sun to part shade and handling average to wet soil. Even after the flowers fade, the grass-like foliage adds texture and movement to a border.
Siberian iris is prone to sulking the first year after transplanting, but usually starts blooming beautifully by the second year.
It’s particularly lovely planted with roses and peonies and makes a gorgeous cut flower. We also like it in a mixed border, where it offsets soft-textured plants like tickseed (Coreopsis spp.) and blue star (Amsonia hubrichtii).
Check out some other iris species as well, including Indiana natives I. cristata (dwarf bearded iris), which makes a lovely groundcover, and I. virginica, a lover of wetlands and ponds.