Find instructions on how to care for and propagate irises. You’ll learn about the different types of irises and how to buy them, as well as find planting and growing tips.
The iris family is large and diverse. Some irises prefer damp, even soggy conditions. Others grow best in dry sites. All bear big, bold flowers that look stunning in the garden or a vase. And all are very colorful—that’s no surprise because Iris was the Greek goddess of the rainbow. You are sure to find one or more suited to your landscape.
Planting Iris Flowers
Irises are one of the most popular and well-known plants in the world. They can be found in all corners of the world, from Europe to the Middle East, North America, and even in India.
Irises are so loved because they come in a wide range of colors and sizes. They range from bright reds to pale pinks, making them very desirable for gardeners and landscapers.
The iris plant is a perennial plant that grows up to three feet high with corms that produce roots over time. With proper care, these plants can last up to 10 years. To plant an iris flower, start by digging a hole about 4 inches deep and wide enough for the root ball or container to transplant your irises.
Growing Iris Flowers
Irises are one of the most popular perennials. They make excellent cut flowers, and they also make a great addition to gardens. There are many different varieties of Iris, and they come in many shapes, sizes, and colors. Flowers can be them in landscapes borders, or even containers.
Irises come into garden centers every Spring, and we get to buy them then, but we can also grow them ourselves from seeds. We need to start with a good location and well-drained soil that provides good drainage, is composted, and is enriched with other organic matter such as manure or leaf mold. The ground needs to be free-draining so that water doesn’t accumulate on the surface around the plant roots, which can cause rot.
Iris Flowers Caring
Iris flowers are an excellent house plant that needs a lot of attention. They require frequent watering and have to be put in a sunny room. If this is not possible, artificial light from the sun will do the trick.
The iris flower is best cared for by placing it in a room with plenty of sunlight or artificial light. You should also make sure to water it regularly and fertilize it at least once every two weeks.
Soil: The soil where the iris flower is planted must be well-draining and should not contain any heavy clay.
Water: Irregular watering is best for iris flowers. Please give them a thorough watering once or twice a week, but then allow the soil to dry out before watering again.
Fertilizer: Provide a liquid fertilizer in early spring and late summer.
Iris Flowers Propagating
Iris flowers are propagated from rhizomes. It can be propagated irises from rhizomes. The best time to cut the rhizomes is springtime, preferably after the ground has been cleared of snow. The soil should then be moistened, and a trench dug for planting.
Different Types of Iris Flowers
The Bearded Ones
Bearded irises have small, fuzzy projections called “beards” on their lower petals. (Irises without the fuzz—notably the Japanese, Siberian, and Louisiana types—are known as “beardless” types.) Enthusiasts have been breeding bearded irises for at least a century, so there are literally thousands of varieties to choose from. They’re classified according to height, ranging from 4-inch dwarfs to the more popular 3 to 4-foot tall varieties.
They tend to bloom in relation to their height—starting with the smallest ones in early spring and finishing with the tallest in early June. You can have a succession of irises blooming by planting some of each size. Bearded irises come in a vast range of colors, including nearly every shade of purple, blue, pink, yellow, and bronze.
Some tall bearded irises must stay fairly dry because they are susceptible to diseases such as bacterial soft rot where summers are hot and humid. If your summers are sultry, stick with the standard dwarfs (8 to 15 inches tall) and intermediates (16 to 27 inches), which are much less susceptible to these diseases.
All bearded irises are fairly easy to grow if you give them a sunny, well-drained site with neutral or slightly acidic soil. Bearded irises grow from rhizomes or fleshy tuberous roots. Do not plant them as deep as you would plant bulbs. Rather, place them so that the tops of the rhizomes show above the soil.
Prepare the soil before planting by mixing in finished compost and some bonemeal, which enhances flower production. Avoid feeding irises high-nitrogen fertilizer—it promotes lush leaf growth instead of flowers and it encourages rot.
If you live in an area with cold winters but not consistent snow cover, layer some mulch on top of your bearded irises after the ground is frozen. Use a loose organic material such as pine boughs or straw. Don’t use leaves or grass clippings, which can pack down and retain too much moisture, causing rot.
The Siberians
If you’re looking for a really tough iris, consider the beardless Siberians (Iris sibirica and I. sanguinea)—they are much less disease-prone than tall bearded irises. They don’t get a leaf spot or rot. And they have stronger, sturdier stems that don’t blow over in the wind as easily as bearded ones can. You’ll find varieties with rich purple or bright yellow flowers.
Siberians are native to moist meadows, so they like more water than the bearded varieties. If your soil is sandy, mix in some compost before planting to help retain moisture. Cover the rhizome with about 2 inches of soil. Be sure that Siberian irises get at least 1 inch of water each week during the first season after planting. And keep the beds well-mulched to prevent weeds from sprouting and the soil moist.
Japanese Irises
Graceful Japanese irises (I. ensata) can turn a moist, acidic problem area into a real showplace. The overall flower size of the Japanese type is the largest of all the irises—some reach 12 inches in diameter. Japanese irises bloom about a month after the tall bearded ones, typically in June or July. They come in all shades of violet flowers, lavender, pink and white.
Acidic soil is essential for these irises. Mixing peat moss into the soil before you plant lowers its pH into the acidic range.
Japanese irises are native to marshy meadows. Although they don’t like to grow directly in water, a moist, sunny, stream bank is ideal. If you don’t have such an ideal site, grow these irises as the Japanese have for centuries: in containers filled with acidic potting soil.
In Japanese parks, pots of irises are set right in the ponds or streams. If you try this in your pond, don’t let the water cover more than the bottom inch of the pot. If you need to, set the pot on a brick or block. In the fall, sink the pots in the ground so that the soil in the pot is flush with the soil around it, then set the pots back in the water in spring.
Like the Siberian types, Japanese iris rhizomes should be covered with 2 inches of soil when planted. Don’t feed them for at least three weeks after planting. Then pamper them with a balanced organic fertilizer in spring, when the foliage is 3 inches tall, and then again after blooming. The clumps must be divided about every three or four years.
Heat-hardy Louisianans
Louisiana irises bask in the heat of the Deep South, where other types wilt. They also grow well as far north as South Dakota and even into the milder parts of Canada. They bloom at about the same time as the tall bearded varieties.
You can choose from more than 400 available varieties of Louisiana irises, in a wide range of colors and heights (12 to 60 inches tall). Generally, they tolerate more shade than other irises (but still need at least 6 hours of sun daily) and they thrive in moist, slightly acidic soil. And you can grow these native bog plants right in a pond if you have one—they don’t mind standing water.
Sources for Irises
Schreiner’s Gardens, Salem, OR
Irris FLowers Expert FLowers