Add drama to your garden by planting the almost true black superstition bearded iris. The petals emerge jet black and turn so deep purple that they actually appear to be black. It is a perennial that thrives in USDA Hardiness Zones four through nine. It comes from a bulb with the flowers blooming in the late spring. The best time to plant the bulbs is in the fall. And by the way, the iris is actually a rhizome and not a true bulb. It comes from a fleshy bulb shaped pod that thrives at or near the surface. In warmer climates, September is the best time. In colder climates you should plant earlier. The idea is to get them into the ground after the heat of summer is over, but well before the first frost occurs.
Iris plants should be located in areas that get direct sunlight. They should get at least six hours of direct sunlight daily. They need well-drained soil to avoid bulb rot. Prepare the soil by adding significant amounts of organic material. If your soil is high in clay content, you should add soil to create elevated mounds to improve drainage. And iris plants thrive best in neutral pH soil. So add bone meal or low nitrogen fertilizer to the soil before planting. Space the bulbs at least 18 inches apart. Make sure that the bulbs are positioned so that the roots point down and the leaf buds are pointing up. Plant them near the surface by digging a hole just twice the size of the bulb. It is important to eliminate all air pockets. You can do this by creating a small mound of soil at the bottom of the hole and then place the iris bulb so that the roots are draped over the base. Press the bulb down and then cover the roots and bulb with a thin layer of soil. Water thoroughly to compact the soil and remove any air pockets.
Iris plants are hardy and they have very strong stems. But if they are planted in a very windy area, it is a good idea to stake them. Deadhead the spent blooms to encourage the growth of more flowers. And once the flowers are finished blooming, trim the entire flower stack back to the ground to prevent seed heads from forming. In the fall, make sure to trim back iris foliage and mulch for protection against the effects of winter. Fertilize with a slow release organic fertilizer.
Aesthetically it is a good idea to plant the iris bulbs in triangular groups of three. This will give your garden a good appearance right from the first year. After that they will propagate and you will get more blooms. They come in clusters, which can be planted together, or separated and be planted singularly in whatever configuration you desire. And every two years it is a good idea to split the plants and re-space them. If you don't do that, you will not get the blooms. Just dig up the plant and cut the roots down. Then you have to cut off the leaves, leaving just one leaf about six inches in height. Dig your hole in the new location and replant the iris. Fan out the old roots and cover them with soil. The new roots will grow out of the back of the bulb and they will feed the growth of the new plant. The plant may not flower in its first year but given time to absorb soil nutrients, it should flower by the second year after replanting.
Maintaining the iris plants is relatively easy. If you get grass or weed growth around the iris beds, get a grass control product that contains sethoxydim. It will kill the grass but will not harm the iris bulbs. If you do notice root rot in any of the plants, get rid of them and sprinkle sulfur powder in the soil around the healthy plants and it should prevent the spread of the rot as well as impede other damaging diseases. When a flower dies you can plant it in the ground. It will contain seeds that will develop into a new bulb shaped rhizome that will grow a new plant.
The black iris is a very dramatic and beautiful addition to your garden. When it offsets white blooming plants it creates a spectacular effect. It is a popular and readily available plant that, when properly cared for, can thrive and produce lovely blooms for many years. Propagation is easy and plentiful so you can fill your garden with irises off of a few plants.