Iris – the flower of the rainbow
They can be unpretentious and pure or wrapped in opulent ruffles, enchanting as miniatures in pots or captivating as magnificent perennials in the flowerbed: Irises are so diverse that they would easily defend their title as the favorite plant of many garden enthusiasts, even in black and white. This love is all the more understandable given the incredible variety of colors offered by the 2016 Perennial of the Year.
Goddess of the Rainbow
"It's not for nothing that the iris was named after the Greek goddess of the rainbow," says Aglaja von Rumohr, long-time manager of the Gräfin von Zeppelin perennial nursery. It seems as if all the colors of the rainbow are truly captured in the three arching standard petals and the three elegantly downward-curving drooping petals of the iris blossoms. The luminosity of the numerous vibrant to pastel shades is reminiscent of exotic orchid blossoms. And like them, they delight the viewer with wonderful color gradients and varied floral patterns with spots, speckles, or fine veins.
Bearded Iris: Royal Appearances
More than 200 iris species continually inspire breeders worldwide to create new varieties. The Gräfin von Zeppelin perennial nursery showcases some of the most beautiful iris varieties. "We specialize in what is arguably the most impressive group: the bearded iris, which blooms primarily in May/June. The tall and medium-tall varieties—the so-called Barbata elatior and Barbata media irises—grow 60 to 110 cm tall and look best when planted in groups," explains Aglaja von Rumohr. Striking varieties are particularly well-suited to showy perennial borders, such as the tricolor Barbata elatior 'Ruban Bleu'. Like many irises, the 85 cm tall variety also boasts a wonderful fragrance. So-called rebloomers, such as the pale yellow Barbata Elatior iris 'Total Recall', promise a pleasant surprise. Rebloomers bloom and fragrantly a second time in the fall – even without pruning. Numerous varieties in a wide range of colors are now available at specialized nurseries.
Wild species: Simply enchanting
The simpler, but no less elegant, flowers of wild species such as the spuria flag (Iris spuria) and the pale iris (Iris pallida) are ideal for natural plantings. Ag-laja von Rumohr recommends planting partners with gray foliage, such as santolina (Santolina chamaecyparissus) and lavender (Lavandula). They complement the green-gray of the iris leaves very well and, like most common iris species, prefer a sunny, relatively dry spot in the garden. Above all, waterlogging must be avoided at all costs, as otherwise the rhizomes – the thick storage organs – can rot (see the info box for further tips). "Irises are best placed not at the very front of the bed, but in the second or third row," advises the iris expert. "Their sword-shaped, gray-green leaves lose their appeal after flowering. Then it's up to the companion plants to distract from them. Furthermore, Iris spuria, in particular, with its stiff, upright leaves, are wonderful structural elements for the background of a flowerbed."
Meadow and marsh iris: figureheads at the pond edge
Iris sibirica, the Latin name for meadow iris, specializes in moist substrates. The delicate blue or violet flowers characteristic of this iris species look best planted in clumps and complement the bright yellow flowers of the marsh iris (Iris pseudacorus). Both species, which grow around 80 cm tall, thrive particularly well at the edge of ponds, although Iris pseudacorus tolerates waterlogging, whereas Iris sibirica does not. Meadow irises also thrive in normal garden soil in a sunny or partially shaded spot and are ideal for small gardens. The decorative seed capsules of the meadow iris are worth noting. Those who enjoy experimenting can leave old flower heads standing and enjoy the pretty eye-catcher in winter.
Dwarf Iris: To kneel down
"The various miniature forms of iris are still far too little known, but they are of a very special charm," reveals Aglaja von Rumohr. Small reticulated irises (Iris reticulata), Iris histrioides, and American dwarf irises (Iris lacustris), for example, are among the species that form bulbs instead of rhizomes and bloom as early as February/March. They are available as pot plants in early spring and can be planted in the garden after flowering. These small but exquisite iris representatives forgo frills and extra-large blooms, but possess beautiful flower markings and the luminosity one longs for after a gray winter. Just like the coquettish dwarf bearded irises (Barbata-Nana group), which bloom in April/May, they ennoble any rock garden and lend planters a touch of divinity.
Successfully care for and propagate bearded iris
"To ensure the successful growth of bearded irises, you should work plenty of washed sand into clay soil before planting," recommends Aglaja von Rumohr of the Gräfin von Zeppelin perennial nursery. To be on the safe side, you can also bed the rhizomes on a two- to three-centimeter layer of sand. The general rule is: plant the rhizomes flat, with approximately the top half still visible above the soil. For optimal plant development, the specialists at the Zeppelin nursery recommend a potassium-rich fertilizer for spring growth. Wilted flower heads should be cut back close to the ground so the plants don't waste energy on seed production.
Particularly important: "After a few years, the rhizomes will have spread in a circular pattern, and the bearded irises will become increasingly lazy to bloom. Then it's time to divide them." To do this, at the end of summer, lift the rhizomes out of the soil with a digging fork. The pieces closest to the edges are the most vital. They are separated with a sharp, clean knife along one of the clearly visible constrictions and replanted. Their leaves are trimmed with scissors to create a roof-like shape – this reduces evaporation until the rhizomes have re-rooted.
TEXT: The Green Media House
