They bloom from late spring to mid-summer. These elegant, low-growing plants have been the subject of poetry and art for centuries in Japan; today, gardeners worldwide enjoy growing these delicate, yet easy-to-grow, plants. These moisture-loving plants make beautiful additions to water features, Zen gardens and rain gardens and also make lovely container garden accents and cut flowers.
Japanese irises are among several "beardless" irises. Unlike German or Dutch irises, these Japanese natives feature petals spaced evenly. They bloom from late spring to mid-summer. These elegant, low-growing plants have been the subject of poetry and art for centuries in Japan; today, gardeners worldwide enjoy growing these delicate, yet easy-to-grow, plants. These moisture-loving plants make beautiful additions to water features, Zen gardens and rain gardens and also make lovely container garden accents and cut flowers.
What are the best planting methods for the Japanese Iris?
Japanese Iris are best grown from rhizomes. Although these plants like wet areas, they won't grow from cuttings placed in water. And, while they produce seeds, germinating Japanese iris from seed can be pretty tricky. Rhizome division of Japanese iris is the easiest way to transplant or share these perennial plants. When you order Japanese iris bulbs from Michigan Bulb, you're actually ordering rhizomes to set into your garden.
So, what's the best way to plant Japanese iris rhizomes? Planting rhizomes is much like planting bulbs. Let's look at a few simple steps.
- Soak Japanese iris rhizomes in cool, clean water overnight before planting. Soaking allows the rhizome to become more flexible, and allows it to absorb enough water to be ready to grow once it's in the ground. Trim off any old roots, and check your iris bulbs for rot, mold, or pests.
- Select a location for your Japanese irises. Japanese irises are great for the wetter areas of your garden, which can be tricky to fill with other bulbs and perennials. They prefer full sun or partial shade, and can handle dappled sunlight shining through a tree or pergola. This iris performs at its very best in full sun in most areas. However, if you live in an area where temperatures typically hit 90 degrees Fahrenheit or higher for much of the summer, you may need to plant in an area with partial shade.
- Prepare your soil. Japanese iris prefer rich, loamy soil that's slightly acidic. Clay and sandy materials won't work well with this plant, as it needs lots of space for water to reach it. Loosen and aerate the soil well, breaking it up to at least six inches deep. Then, add in loam and compost to keep the soil light and well-nutritionalized. Light soil that isn't packed too tightly is called "friable" soil, and it's absolutely essential to your Japanese iris' health. Soil particles that are packed too closely together can actually suffocate this plant.
- Next, it's time to set your Japanese iris. Dig a hole for each iris rhizome, and set the irises in the ground with the roots facing down and the eyes facing up. Japanese iris should be planted with the top of the rhizome, where the leaves connect, visible above the soil, with six or eight inches of space between the plants. Check your variety for more specific information.
- Next, backfill over the iris. Fill in around the rhizome, leaving just the top of the bulb, where the leaves connect to it visible.
- Water your irises well. Japanese iris appreciate consistent moisture, so keeping them evenly watered will have huge benefits throughout the growing season.
- In the first few weeks after planting in spring, don't let your irises dry out. Keep them watered by adding moisture every few days until they sprout.
- Don't give up hope if your irises don't bloom in the first year! Japanese iris gardening is a long-term affair, so give these plants at least two seasons to produce those fantastic flowers. Most Japanese iris will bloom in the second season, and prolifically after that.
Growing Japanese iris is a fairly simple proposition, especially in those areas where growing can be tough due to dampness and overly rich soil. It's easy to see why gardeners love these unique iris plants.
When is the best time to plant Japanese Iris?
Most varieties of Japanese iris are best planted in the spring, after all threat of frost has passed. Irises like to become established in their first year, so planting at springtime gives your irises plenty of time to put down roots before the winter. If you order Japanese Iris from Michigan Bulb, we'll send them at just the right time to plant! If you're unable to plant quickly, you can store the iris rhizomes in a cool, dry area until you're able to get them into the ground.
How long do Japanese Iris blooms last?
Japanese iris are among the last irises to bloom in the garden, with bloom times ranging from early to late summer. These blooms will last for over a week each in the garden, and make excellent cut flowers, too. Because they offer multiple blooms per stem, Japanese iris often flower longer than any particular single bloom flower.
What kind of sunlight does Japanese Iris need?
Japanese iris need at least six hours of sunlight per day for optimal blooming. Most Japanese iris can handle a full day of sun with ease, and actually produce more flowers when receiving eight hours of direct sunlight! However, that trend can reverse in hot regions. In southern zones, Japanese iris can be burned by too much heat. No worries though: Southern gardeners can still successfully grow Japanese irises. Just place them in a location that receives morning light and afternoon shade.
What is the best watering method for Japanese Iris?
Some gardeners have great success with "trench irrigation," or directing rainwater into the roots of your plant by creating a trench where the flower is planted. However, that's not necessary for most gardeners. To water your Japanese iris successfully, add moisture several times per week. Water the base of the plant, instead of the flowers, and water early in the day, before the sun becomes bright. Japanese iris are also plants that are suitable for planting near or inside water features, such as ponds. If you want to try planting Japanese iris in a pond, pot your iris in a soil such as a heavy loam, making sure the top of the rhizome is above the water line.