Classically handsome Siberian iris is a must-have for every garden. Sporting stems of elegant, beardless flowers in late spring to early summer, Siberian iris cultivars come in shades of blue-violet, purple, wine, lavender, pink, white, and yellow.
Unlike the stiff foliage of some iris species, Siberian iris has narrow leaves that give the plant a graceful, grasslike effect. This combination of beautiful flowers and attractive foliage makes Siberian iris a standout in the perennial garden all summer long.
Common name: Siberian iris
Botanical name: Iris sibirica
Plant type: Herbaceous perennial
Zones: 4 to 9
Height: 20 to 40 inches
Family: Iridaceae, iris family
- Sun: Full sun.
- Soil: Prefers moist garden loam. Tolerates a range of soil pH.
- Moisture: Soil should be evenly moist and well-drained. Water Siberian iris adequately during dry spells.
- Mulch: None, or a 1-inch layer of fine compost.
- Pruning: Cut back foliage in late fall or early spring.
- Fertiliser: Apply a balanced fertiliser once or twice during the growing season.
- Siberian iris tends to die out in the centre of crowded clumps. Divide the clumps every 3 to 5 years and reset the divisions to maintain healthy plants.
- Seeds collected from cultivars will not grow into plants that look like their parents. If you want to collect seeds anyway, sow them in an outdoor seedbed in the fall.
Pests and diseases
- Siberian iris is much less susceptible to iris borers than bearded iris, but these insects can occasionally be a problem. Check for borer damage when dividing clumps; discard infested rhizomes.
- Siberian iris blooms at the same time as some peonies, and the two perennials make a stunning pair. Pink peonies and deep purple Siberian iris are a particularly dramatic duo.
- Siberian iris foliage looks similar to ornamental grass and can be used in similar ways in the garden.
- Most Siberian iris cultivars are not heavy seed producers. The dark brown seedpods are attractive and make a nice addition to dried bouquets.
- There are dozens of Siberian iris cultivars. Here are just a few favourites:
- ‘Butter and Sugar’-one of the first yellow and white bicolors.
- ‘Caesar’s Brother’-tall, with velvety deep purple flowers.
- ‘Ego’-ruffled light lavender-blue flowers.
- ‘Halcyon Seas’-medium bluish purple flowers.
- ‘Heliotrope Bouquet’-large mauve flowers.
- ‘Lady Vanessa’-wine-red flowers.
- ‘Pink Haze’-lavender-pink flowers.
- ‘Ruffled Velvet’-ruffled reddish purple flowers.
- ‘White Swirls’-large ruffled white flowers.
All in the family
- There are several hundred species of iris with a wide range of sizes and flowering habits. They are native to Asia, Europe, and North America.
- Siberian iris is part of the beardless iris group, which also includes Japanese, Louisiana, and spuria iris.
- The iris has long been used in decorative arts, including the well-known fleur-de-lis design that originally served as the emblem for French royalty.