Iris is a vast genus of plants ranging from the tiny Dwarf Iris (4 inches) to the giant Japanese Iris (4 foot). The Iris is named after the Greek goddess who rode rainbows and refers to the wide variety of flower colors found among the many species. Irises are hardy, reliable, and easy to grow, blooming from early spring to summer. Some Irises, mostly bearded hybrids, will flower again later in the summer. Irises also attract butterflies and hummingbirds and make lovely cut flowers. The Iris is the French royal standard fleur-de-lis.
Most Irises have a similar flower pattern - they are made up of 3 inner upright petals called standards and three large outer lower petals called falls. Also known as flag or sword lily, Irises are divided into 2 groups: bulbous (Dwarf [Reticulata] and Dutch) and rhizomatous (Bearded, Siberian and Japanese) Irises. The Rhizomatous Irises spread from thick underground stems. Bearded Iris are so-called because they have soft hairs along the center of the falls. Bulbous Irises grow from bulbs rather than rhizomes and are generally smaller.
THE BULBOUS IRISES:
Iris Reticulata are well known dwarfs that grow 4-5" high and bloom in February or March. They come in lovely shades of blue, purple, violet and yellow. The standards are usually a lighter color, sometimes with a yellow or orange stripe down the center. They like well-drained but moisture holding soil. If they are too dry they may split into bulbils and not flower for a couple of years. Deep planting is said to help keep them from dividing too much. Plant in full sun in the Fall - they will often bloom before the snow melts in the Spring. You can also force them in a pot indoors. They're also known as "Rock Garden Iris" because they are small and so doggone cute!
Dutch Irises are also grown from bulbs and are used to fill the gap between Spring and Summer plants, appearing in June. Also known as 'Hollandia', they are a long-lasting, excellent cut flower or border item. They come in shades of blue, yellow, violet and white, all with a golden stripe on the lower petals. They'll come back in Southern gardens. Dutch Irises love full sun, so avoid planting in the shade. Too much summer rain can rot Dutch Iris, so you may have to lift them and dry them, storing them in a cool dark place or just count on re-planting fresh stock every year. Dutch Irises are good for forcing. Plant 5 bulbs to a pot for late winter flowers inside.
THE RHIZOMATOUS IRISES:
Bearded Irises are considered the most elegant with their stunning colors. They make long-lasting cut flowers. They are distinguished by their "beards" - tufts of fine hairs, which are rows of colored hair along the center of the downturned petals. Bearded Irises are sun-loving and flower last of the Irises, in early summer.
Japanese Iris (Ensata) is a magnificent group of Irises that are native to Japan. The beautiful large blooms are orchid-like, ruffled and flat. They can be planted practically anywhere, including in the water garden. They love moisture and can be planted in pots in water. If planted in the ground, they should be planted in a distinct "depression" in heavy soil to assist in supplying moisture to the plant. You can dig them up every 4 years to divide, cutting into thirds.
Siberian Irises are tough, low maintenance plants. They have abundant blooms, even in difficult spots and are rarely bothered by pests. They're drought resistant and tolerate poor drainage and will do well anywhere they can get a half day of sun. The foliage remains attractive throughout the growing season. Plant the crown just below the soil surface.
The Rhizomatous Irises are planted horizontally, leaves up and roots down. Never plant more than 1" deep, and leave about 1/3rd of the rhizome showing. Every 3 or 4 years you can cut the rhizome in 2 or 3 pieces and replant to multiply your stand. All should be planted in a permanent spot where they can remain for many years as they resent being disturbed. They are heavy feeders and need to be fertilized regularly.
Bulbous Irises are smaller than those of the Rhizomatous Irises and should be planted like any bulb, such as daffodils and tulips. As a general rule plant them 3 times as deep as their height, a little shallower in the South.
For the Rhizomatous Irises, after bloom, cut off the entire flower stem to discourage rot, leaving the leaves to nourish the bulb. In the fall, cut the fans back to 4 inches, removing any dead shriveled leaves. For the bulbous Irises, like all bulbs, allow the foliage to die back naturally.
Iris borers can be a problem with the Rhizomatous Irises. If troubled by them, clean up the bed thoroughly, dig up any infested rhizomes and cut out the borers. Dust with sulfur and replant.
We carry all of the 5 of the above-mentioned types of Irises in the Fall. They can be planted now for spring bloom next year. In addition, the Siberian and Japanese Irises can be purchased and planted in the Spring for Summer bloom. We also carry Japanese Iris Clumps, which are mature, undivided field-run clumps consisting of 15 to 20 eyes, and Bearded, Siberian and Japanese Iris Bulbs by the Bushel or Half Bushel.