Iris is a magnificent flower. It is named after the Iris in Greek mythology, the goddess of the rainbow, because these flowers come in so many beautiful colors. They have been cultivated in ancient Greece, ancient Egypt, Asia and the Mediterranean for thousands of years. There are varieties native to Asia, Europe and the Americas. The iris is associated with the Fleur-de-Lis of France (just like the lily), and the Iris is the state flower of Tennessee. They became commonly grown in Europe in the 1500s, and some were imported to the Americas (Virginia) as early as the 1600s.
The different species of iris
There are literally hundreds of different species of irises. Irises grow from rhizomes, which are long, thick root-like tubers that grow (and need to be planted) on or near the surface of the soil. Structurally, they are part of the stem of the plant, but they store nutrients and also a little moisture so that the plant blooms again once planted. There are basically two main types.
The first is the rhizomatous iris. On them, the root structure (rhizome) resembles a piece of stem with roots protruding from the bottom. They are the most common, and the German“bearded iris” belongs to this group. The second type is called bulbous iris, or simply “iris bulbs”.”Although they are still technically rhizomes, they are more often called simply bulbs, even by professional gardeners, and are recognized as a different type of iris. Reticulata and Dutch Iris have several varieties of iris bulbs. Bulb types will be smaller plants and are just as beautiful.
- Iris
- Perennial
- Full sun
- Fertile, well drained, neutral to slightly acidic soil (pH 6.8-7.0)
- Indoor Boot Instructions
- Plant from after summer to early autumn.
- 24 ” apart
Growing in containers:
- Flowers can be grown in containers with a little care
- Large pots-at least 12 “wide for larger irises, 8” wide for dwarf varieties
- Plant on the surface and ensure good drainage and water frequently.
- Irrigation / Maintenance information
- Climatic zones 3-9 for Siberian Iris and Japanese Iris, 5-9 for most others
Planting irises
Iris rhizomes should be planted in the soil that drains very well, and autumn planting is best. It is important to avoid soil that is too soggy as this can lead to health issue. They do best in moist but not muddy soil. Choose a place that will get a lot of sun. Plant the rhizomes or bulbs about 6 weeks before the first autumn frosts to let them settle. Dig and loosen the soil in the area where the iris will be planted, in a large area about 6 inches deep, and mix the compost. Dig a large shallow hole, 8 to 10 inches wide and 3 to 4 inches deep. Collect some soil in the center and spread the roots on top to keep them a little apart. Fill the hole by covering the rhizome and leaving the top just above the surface. Do not cover them completely, they should be right on the surface. Plant alone or in groups, but keep each plant about 24 inches apart. Water well, keeping them moist after the first planting. If you divide the existing irises, they can be planted at any time of the season, there is no need to wait, but most likely they will not bloom until the next spring or summer. Do not plant earlier than about 2 weeks after the last frost in spring.
It is better to leave the existing iris rhizomes in the ground than to remove them for storage during the winter. In heat up climates, when temperatures are low of 50 F F or more, it is best to water them from time to time, but do not water in areas with colder winters. Irises are quite frost-resistant. Established plants can withstand subzero temperatures quite well, but if there is a hard frosty frost (-25 F
Irises are also great as potted plants. The main thing to remember is to get an extremely wide dish. 12 inches wide and 8 inches deep is a good size for a single plant, but more is better. If you want to plant several flowers in a pot, take one at least 24″ in diameter, and still 8 inches deep, and plant 2 plants, on opposite sides of the container. This leaves enough room for the roots, which are shallow but widely spread. As you can guess, a potted iris needs a pot that drains very well.
Caring for the iris
When watering, make sure that the soil is completely moist. Water until it starts to drip from the drainage holes. In very hot and dry weather, water more often. Fertilizing is necessary for irises in pots twice a year. First in the spring at the beginning of the growing season, then again after they have fully bloomed. In winter, it is usually best to store plants indoors, in a cool place such as an unheated garage. Plants need a cooler period to allow the rhizomes to go dormant in anticipation of spring. Irises do not have the protection from the bitter cold in pots that they have when planted in the ground.
Companion Iris Planting
There are several flowers and shrubs that are excellent companion plants for irises. Usually, companion plants are chosen for their nutritional value or to help with pest resistance. Flower companions of irises are chosen for the times when they bloom. Many irises bloom in early spring, so it’s common to plant things like violets, daffodils and peonies, as well as lilacs and daisies that bloom a little after to brighten the garden as the iris fades. Other flowers such as da da Lavender also has the advantage of attracting ladybugs, which can help repel aphids from the garden.
Pests and health issues of the iris
Aphids are a known iris pest, as are thrips, but a specific pest that can cause problems in the eastern United States is the iris borer. Iris borers are small pink caterpillars that will become moths when mature. The main problem of these creatures is that they make their way into a bulb or rhizome of the iris, and once inside they are difficult to detect. The rhizome will begin to decompose and rot from the inside. They will eat holes in the leaves and the appearance of the leaves will change, with dark stripes appearing. The edges will become jagged. Insecticide is an effective treatment, but nematodes are an insect that finish borers, and these can be released into the garden.
health issues affecting the iris include fungal health issues such as leaf spots and rust, and mosaic viruses. and botry Rot caused by iris borers can also trigger a serious infection, and severe infection from any source means the entire plant will need to be dug up and removed and disposed of away from the garden. Most health issues can be prevented by properly spacing plants, weeding and avoiding aerial watering.
New iris flowers are usually produced by carefully dividing the rhizome. Carefully break the rhizome by hand into a joint and make sure that both sides have abundant roots. Each part can be replanted separately in the fall. This will ensure that the plant becomes the same variety. Iris can also be grown from seeds. Since most irises are hybrids, there is no ideal way to predict the specific appearance of an iris produced by seed. It is likely that they are still very cute, but differ in some respects from the mother plant.
Planting irises from seeds
Plants produce pods that turn brown when ready to divide. It’s a good idea to break the pods and let the seeds dry for a few months. Plant them in the garden, in a place reserved for them at the end of autumn (October is a good bet). Space them about 1 inch apart and plant them about 1/2 to 3/4 inches deep. Let them stay in the ground during the winter. When spring comes, dig carefully and replant them at the usual distance of about 24 inches from each other. This will allow them to fully grow and see how to cope. It’s a good idea to keep a good record of the type of plant each seed comes from. All plants from seeds that grow healthy and strong with beautiful and unique flowers should be kept and developed for a year or two, then the rhizomes can be divided to create new plants of the same genus.