Siberian iris

If you are looking for a bright blue early summer bloomer for the pond edge, the Siberian iris is the right choice. In this profile you will learn how to plant the native wild shrub correctly in the garden.

Jun 02, 2021 07:10 am
readtime icon 7 Minutes
Growth type
  • Perennial plant
  • rhizome
Growth height (from)
from 30 cm to 150 cm
Growth width (from)
from 40 cm to 60 cm
Growth characteristics
  • upright
  • horst-forming
Flower color
  • purple
  • blue
  • white
  • multicolored
Flowering time (month)
  • May to June
Flower shape
  • Uniflorous
  • terminal
Leaf color
  • green
page format
  • narrow
Sheet properties
  • Autumn coloring
Fruit shape
  • Capsule
  • sunny to semi-shade
Soil type
  • sandy to loamy
Soil Moisture
  • fresh to humid
ph value
  • alkaline to weakly acidic
Lime compatibility
  • lime-tolerant
Nutrient requirements
  • moderately nutritious
  • rich in humus
Decorative or utility value
  • Flower Decoration
  • native wild plant
  • non-toxic
Winter Hardness
  • hardy
  • Flowerbeds
  • Bouquets
  • flower meadows
  • Single position
  • Group planting
  • Pond planting
Garden style
  • Flower garden
  • natural garden
  • Water garden

The Siberian iris (Iris sibirica) belongs to the large genus of Irises, often simply called iris, which includes 300 species. And no, the shrub doesn’t feel at home in Siberia. Throughout Europe it is found sporadically in lowland moors, on the banks of ponds, in ditches or on damp meadows. That is what gave it the name Bog Iris. You can find them on the Ammersee as well as in the Taunus, on Lake Constance and in Mecklenburg-Western Pomerania. Everywhere, the flower of the year 2010 is endangered due to surface draining drying or intensive use or eutrophication. It is classified as critically endangered on the Red List. Iris sibirica has been cultivated in the garden since the 16th century, it is already mentioned in Charlemagne's estate ordinance, and with its stylish flowers it was one of the preferred subjects in Art Nouveau.


Typical of the Siberian iris are rhizomes that run close to the surface of the earth - this is why it is also included in the rhizome iris (in contrast to the bulb iris). Over time, Iris sibirica forms thick tufts. Depending on the variety, the plants reach heights of 11.81 to 59.05 inches, and several flowers appear on one shoot towards the middle and end of June.

Flowers of the Siberian Iris
The flowers of the Siberian iris are visibly veined

The delicate, narrow, initially upturned leaves of Iris sibirica resemble grasses and turn an attractive yellow to bronze color in fall. They are fresh green, only 0.78 to 2.36 inches wide and thus clearly differ from the usual "sword shape" of the other iris species. The leaves are up to 17.71 inches long.


From reddish buds, the three-part flower opens in May and June with the light blue, dark blue veined petals. Up to five flowers sit on the branched shoot, which protrudes well above the leaves. The three inner petals are slightly darker than the outer ones. The flower's hanging petals are smooth, which is why the Siberian iris is also a part of the group of beardless irises. The standard stands upright over the hanging petals.


The shrubs form capsules with gaps in the wall, which when dried out still are a delight to see throughout winter.

Seed capsule of the Siberian Iris
After flowering, the Siberian iris forms decorative seed pods

Iris sibirica is very adaptable: Sunny and partially shaded places in flat and hilly areas are suitable.


The meadow iris prefers a moist to fresh, moderately nutrient-rich soil with a lot of compost. Short dry spells are also tolerated well. The pH value can vary between alkaline and weakly acidic. Only high nitrogen values are not tolerated. From the 1950s onwards, great emphasis was placed on adapting to "normal" garden soils.


Planting between late March and October is recommended, although experts believe that Iris sibirica planted early will develop better than fall plantings. Flat planting is important; the upper third of the rhizomes should still look out of the earth. The roots point diagonally downwards. The planting distance can vary depending on the variety, usually 9.84 inches is appropriate.


Nitrogen should be avoided with the Siberian iris, at best a small amount of compost in spring is welcome. Withered stems and leaves are best cut back so that too much energy is not put into the seed formation. The foliage should not be cut back until next spring.


The tufts should be divided and replanted every four to five years. To do this, dig up the bog iris and separate it into several parts. The outer parts are the most vital, only those are usually replanted. To reduce evaporation, cut the foliage back by about half before putting them back into place.

Where to plant

Original varieties of Iris sibirica fit well in a natural garden setting, for example in meadows or at the edge of a pond. However, it cannot prevail against strong grass clusters. Large-flowered and double-flowered varieties can easily keep up with magnificent perennials. The globeflower, Jacob’s ladder, Lady’s mantle and daylily, for example, can be used as plant partners in damp areas. In shrub beds Phloxes, tradescantias and clove root, for example, are excellent companions.

Himalayan spurge “Fireglow” and Siberian iris
The bright orange flowers of the Himalayan spurge “Fireglow” form a great contrast to the blue flowers of the Siberian iris

The beauty of the Siberian iris shines out in a vase.


Iris sibirica has long been out of the shadow of the irises - or better: High beard iris – come to the fore. The Siberian iris is now available in a wide variety of colors, with breeders now also working with quadruple chromosome sets. However, these triploid irises are usually more demanding and want to be cared for much more than those with a diploid chromosome set. You can usually recognize them by their larger flowers and a wavy edge - this effect is called "Ruffling". Filled varieties are brought into play, especially by Japanese and US breeders. Caution: Iris sibirica are addictive for many gardening enthusiasts!

Iris sibirica ‘Butter and Sugar’
Iris sibirica ‘Butter and Sugar blooms in a delicate light yellow’

‘White Swirl’ and ‘Viel Schnee’ shine in white with the distinctive, pale yellow throat. "Sparkling Rose", "Ewen", "Burgundy Velvet" and "Siberian Night" offer shades of red between wine red and purple. The color yellow is represented by ‘Dreaming Yellow’ and ‘Butter and Sugar’; ‘Tom Schafer’ lights up golden yellow. Then of course the original flower color, the blue: In turquoise blue shines ‘Cambridge, in night blue the variety ‘Caesar’s Brother’. ‘Blue Celeste’ has retained its original meadow charm. The ‘Concord Crush’ variety, which blooms for a second time in late summer, looks like real cat eyes.


Bog Iris should be sown as a cold germinator possibly in fall. The seeds are covered 0.39 to 0.78 inches with soil. Dividing the rhizomes usually leads to success faster and produces true-to-variety offspring.

Diseases and Pests

Snails and mice love to eat the leaves and rhizomes. The best way to combat iris rust and leaf burn is to cut off affected areas. If aphids spread on Iris sibirica in the dry spring, simply spray them off with a sharp water jet.