Iris (eye-riss), Iridaceae Family. More than 200 species of perennial herbs make up the genus Iris. They range in size from tiny plants small enough to fit in the cupped hand to regal plants as tall as 5 feet.
Called rainbow flower, Iris covers the entire color spectrum and obviously makes a marvelous show at bloom time. Since the petals contain a high percentage of water, the best ones have a luminous quality. Some are frilly and ruffled; others are chic and chiseled. They are highly prized for the glamour they contribute to a planting composition and for their decorative quality as cut flowers. Although most bloom in spring and early summer, a rainbow of color can be created from early spring through summer, fall and in mild climates, on into winter.
Some plants grow from bulbs, but most grow from rhizomes or modified stems that creep along the ground and send roots down into the soil. Leaves are narrow, some sword-shaped, and others thin as grass blades. Flowers have six conspicuous parts – three upper usually erect petals called standards, and three horizontal or drooping sepals called falls.
Iris are not only spectacular to look at, they are easy to grow. Iris have two requirements, lots of sun and good drainage. Irises thrive in moist soil but are least susceptible to root rot, when grown in soil of moderate fertility. Plant roots deep in a well worked bed and place the rhizome shallowly with a light covering of soil, half in half out of the soil. In areas where the ground freezes, good mulching will prevent the rhizomes from heaving out of the soil during winter.
Tall Bearded Irises will bloom relatively well with half day sun, but more sun equals more flowers. Drainage is the most critical growing factor; too much water will cause the rhizomes to rot. Bearded Irises will grow in any good garden soil with good drainage.
Irises should be fertilized 3 times per year: first in the spring when new growth appears, second right after blooming, and third in the fall. When planting for the first time or transplanting, use a no-nitrogen fertilizer such as 0-10-10.
Division is recommended every 3 to 4 years to maintain healthy plants and achieve the maximum bloom. The best time of year to plant irises is in late summer after they have bloomed. Dig the entire clump and use a sharp knife to cut apart the rhizomes. Keep only the newer ones around the outer edge of the clump and discard the old, woody center. Replant new divisions 12 to 18 inches apart to allow plenty room for new growth and good air circulation. Planting at the correct level is critical to the plant's health and flower production. Rhizomes should be planted so the soil barely covers the top of them, or 1 to 2 inches. deep to prevent soft rot.
Attributes: Use as border plants, for cut or dried flowers, drought tolerant, fragrant flowers, en mass planting, salt tolerant, deer and rabbit resistant.
Louisiana Irises grow best in wet to boggy soil or in shallow water up to four inches deep. They can also be grown in the garden with consistent moisture. However, they tend to bloom heaviest when grown in water. The soil should be acidic, as the plants will be pale in color and overall weaker when grown in soil with a higher pH.
Louisiana Irises bloom best in full sun but will also grow in partial shade. Late spring is the ideal time to transplant the rhizomes, though late summer or early fall is also acceptable. Do not transplant them in the heat of summer or in late fall. Plants will multiply quickly if sited properly.
These plants are heavy feeders, especially in zones where the growing season is relatively short. Provide a dose of liquid fertilizer on a regular schedule for best results. Provide pine straw or other mulch in the fall, but be sure to pull away the mulch early in the spring to prevent rot.
Attributes: bog plant, border plant, cut flower, and mass plantings. Attracts hummingbirds. Deer and rabbit resistant.
Siberian Iris will tolerate a wide range of soils, but prefers very moist, organic, slightly acid soil. It will perform in boggy conditions, and will survive poor, dry soil if its thick roots penetrate deep enough. They will tolerate part shade in warmer zones.
New clumps may take two or three years to become firmly established and bloom profusely. It is best not to divide iris during bloom period, wait until fall.
Attributes: bog plant, border plant, container, cut flower, and mass plantings. disease resistance Attracts hummingbirds. They can also be grown under Black Walnut trees. Siberian Irises bloom before Japanese Irises but after Tall Bearded Irises.