Siberian iris: A beautiful and hardy addition to your garden


These striking flowers of Iris sibirica are native to Europe and Asia, and have been cultivated for centuries for their beauty and resilience.


Siberian irises are known for their showy blooms, which come in a range of colors, from deep purple to pure white. The sepals are typically the outermost whorl of protective leaf-like structures that surround and enclose the flower bud as it develops. In the case of the Siberian iris, three modified sepals make up the falls and are large and showy, often the most visually striking part of the flower. These falls iris are often adorned with intricate patterns or markings, which add to their visual appeal. The standards, which are the three smaller, upright petals nestled inside the falls, are modified petals. Together, the modified sepals (falls) and petals (standards) give the Siberian iris its distinctive appearance. The markings on its petals, especially near the base of the falls, are known as the signal and are frequently spread as a colorful pattern.

Siberian irises typically bloom in mid to late spring, for several weeks, depending on the climate and growing conditions.

The foliage of the Siberian Iris is also attractive, with long, narrow leaves that grow in a clump and provide a lovely backdrop for the flowers. The leaves are typically deep green, although some cultivars have a bluish tinge or variegation. Cultivars grow to a height of 24 to 36 inches when mature, most of them around 30 inches tall.

Growing Conditions

One of the reasons the Siberian iris is so popular with gardeners is its hardiness, in USDA zones 3-9. This plant can survive in a wide range of growing conditions, from full sun to partial shade, and can tolerate a range of soil types, from sandy to clay.

Siberian irises prefer moist soil, but are drought-tolerant once established. They are also resistant to pests and diseases, making them an excellent choice for low-maintenance gardens.

To plant Siberian Irises, choose a location with well-draining soil and adequate sunlight. Dig a hole that is large enough to accommodate the roots, and place the plant in the hole, covering the roots with soil.

Water the plant well after planting, and continue to water regularly during dry spells. Fertilize once a year with a balanced fertilizer, and divide the plants every few years to prevent overcrowding and improve flowering.

Siberian Irises do not require staking, but taller varieties may benefit from support during heavy rains or wind. Deadhead spent blooms to encourage additional flowering.

I trim back the yellowing foliage in the early fall season.

Iris sibirica ‘Blue King’


Siberian irises are fast growers and can be propagated through division, so you can easily multiply your collection over time.

Older clumps may develop a bare center. Dividing them is a great way to keep these hardy plants healthy and blooming year after year. Here’s a step-by-step guide to dividing older clumps of Siberian Iris:

  1. Choose the right time: The best time to divide Siberian Iris is in the fall, after the plants have finished blooming and the foliage has died back. This gives the plants time to establish new roots before the winter.
  2. Prepare the soil: Before you start digging up your plants, make sure the soil is moist and easy to work with. This will make it easier to remove the clumps without damaging the roots.
  3. Dig up the clumps: Use a spade or fork to carefully dig up the entire clump of Siberian Iris. Be careful not to damage the roots or the rhizomes.
  4. Separate the clumps: Once you have removed the clump from the ground, use your hands or a sharp knife to separate it into smaller clumps. Each clump should have a healthy rhizome and several strong roots.
  5. Trim the foliage: Cut back the foliage on each clump to about six inches. This will help the plant conserve energy as it establishes new roots.
  6. Replant the clumps: Dig a hole for each clump that is deep enough to accommodate the roots and rhizome. Make sure the soil is moist and well-draining, and add some compost or other organic matter to the hole.
  7. Water and mulch: Once you have replanted your Siberian Iris clumps, water them thoroughly and add a layer of mulch around the base of each plant. This will help to retain moisture and keep the soil temperature stable.
  8. Dividing older clumps of Siberian Iris is an easy and effective way to keep these beautiful plants healthy and blooming year after year. With a little care and attention, your divided clumps will quickly establish new roots and produce even more stunning blooms.

Design Ideas & Cultivars

Siberian Irises are versatile plants that can be used in a variety of garden settings. They look lovely planted in masses, and can be used to create a colorful border or to fill in gaps in a cottage garden’s perennial bed. They also make excellent cut flowers, and can be used in bouquets or arrangements.

There are many different cultivars available, each with its own unique characteristics. When choosing a cultivar of Siberian Iris, consider the size of your garden and the overall color scheme you are going for. For instance, dark purple varieties are stunning next to white flowers if they bloom at the same time.

Some popular companion plants for Siberian Irises include peonies, daylilies, and hostas. You can also mix different colors and varieties of Siberian Irises for a stunning display of color and texture.

Some popular companion plants for Siberian Irises include peonies, daylilies, and hostas. You can also mix different colors and varieties of Siberian Irises for a stunning display of color and texture.

I have more than a dozen cultivars of Siberian irises in my garden and I am always looking for more. Here are some of the most popular:

  1. ‘Black Joker’: This stunning cultivar showcases deep purple and black flowers with yellow and white markings.
  2. ‘Blue King’: The falls of this common cultivar are typically a deep violet-blue color, while the inner standards are lighter in color and may have a slight purplish tinge. The signals are a bright yellow color and form a distinctive pattern on the falls.
  3. ‘Butter and Sugar’: This cultivar produces beautiful white flowers with yellow and green markings on the falls.
  4. ‘Carree Lee’: The dark pink flowers of this cultivar show deep rose veins on falls with a golden yellow center.
  5. ‘Caesar’s Brother’: One of the oldest and but still one of the best cultivars there is with deep purple flowers and yellow and white blaze with black veining.
  6. ‘Miss Apple’: Closer to true red than other cultivars, it features 4 inch flowers with magenta standards and deep red falls with gold markings.
  7. ‘On Mulberry Street’: The flowers of this cultivar are a unique shade of purplish-magenta with a hint of blue.
  8. ‘Painted Woman’: The flowers of this charming cultivar are a striking combination of violet-blue and white. The petals are streaked and speckled with white, with red violet veins, giving the flowers a unique and artistic look.
  9. ‘Paprikash’: The flowers with warm shade of burnt orange with yellow and gold undertones are reminiscent of paprika, hence the name.
  10. ‘Pink Parfait’: The delicate pink coloration of this cultivar differs from the other Siberian irises.
  11. ‘Silver Edge’: The rich sky-blue flowers of this very popular cultivar are adorned with a distinctive silver edge.
  12. ‘Tipped in Blue’: A newer and unusual variety, it offers outstanding 6 inch blooms of rare, yellow color with a little blue in the middle and at the tips of the petals.
  13. ‘White Swirl’: This tall iris (36-40″) has almost white, rounded, ruffled flowers adorned with a delicate golden flush at the base of each fall.

In conclusion, the Siberian iris is a beautiful and hardy plant that is well-suited to a wide range of garden settings. With their striking blooms and low-maintenance care requirements, these plants are a great choice for any gardener looking to add some color and interest to their landscape.

Previous post

Standing tall: Creative methods for staking your peonies

Next post

Beauty and the beard: Exploring the stunning bearded iris