Perhaps one of the easiest Iris to grow is the Siberian Iris (Iris sibirica). These hardy perennial plants cope well with damp positions, part shade and don’t seem to suffer from many problems at all. While they will flower more profusely in full sun, a little shade won’t stop them from performing well, making them one of the most reliable Iris for Australian gardens.
Unlike Bearded Iris, which prefer excellent drainage, Siberian Iris thrive in moist, well-drained soil and will even tolerate wet conditions. This makes them an excellent choice for planting beside ponds, streams, water features or in any part of the garden that stays consistently moist.
Why Grow Siberian Iris?
Siberian Iris combine graceful flowers with attractive foliage that provides interest well beyond the flowering season. Their elegant, grass-like leaves remain green throughout summer, making them valuable border plants even after the blooms have faded.
They are long-lived, cold hardy perennials that fit beautifully into cottage gardens, perennial borders, naturalistic plantings and rain gardens. They also attract pollinating insects and make excellent cut flowers for indoor arrangements.
Growing Conditions
Growing Siberian Iris is easy provided they have the right conditions.
- Botanical name: Iris sibirica
- Position: Full sun to part shade
- Soil: Moist, well-drained soil enriched with organic matter
- Soil pH: Neutral to slightly acidic, although they adapt to most garden soils
- Height: 20cm to 1 metre depending on the variety
- Spacing: Plant around 30–45cm apart
- Flowering: Late spring to early summer
- Frost tolerance: Excellent
Although they appreciate moisture, established plants are surprisingly resilient and require very little attention.
Flowering and Varieties
Flowering in late spring to early summer, Siberian Iris produce elegant blooms held above upright clumps of narrow foliage. Most varieties flower in shades of blue and purple, although white, pink and bi-coloured cultivars are also available.
One variety worth looking for is Iris sibirica ‘Summer Skies’, an unusual bi-coloured selection with delicate pale blue flowers that add a softer touch to the garden.
A wide range of Siberian Iris varieties is available from online nurseries during autumn and winter, which is also the ideal time to plant new rhizomes.
Planting Siberian Iris
The best time to plant Siberian Iris is from autumn through to early spring while the soil is cool and moist.
Prepare the soil by incorporating compost or well-rotted organic matter before planting. Position the rhizomes so the crown sits just below the soil surface and water well after planting. Apply mulch around the plants to help retain moisture, taking care not to cover the crown.
Keep the soil consistently moist while plants establish.
Growing and Care
These are among the easiest Iris to care for and are reasonably maintenance free once established.
Apply a balanced, all-purpose fertiliser in early spring as new growth appears. This is also the best time to divide established clumps if they have become crowded or flowering has declined. Dividing every four to five years helps maintain vigorous growth and abundant flowers.
Regular watering during prolonged dry periods will encourage better flowering, particularly in warmer climates. Removing spent flower stems will keep plants tidy, while the attractive foliage continues to provide structure throughout summer.
Why Gardeners Love Siberian Iris
Siberian Iris are reliable performers that ask for very little in return. They are:
- easy to grow
- cold hardy
- tolerant of damp soils
- suitable for full sun or part shade
- excellent cut flowers
- attractive to pollinators
- ideal for borders, pond edges and rain gardens
- long-lived perennial plants
Whether planted individually or in drifts, they provide elegant late spring colour and attractive foliage for months afterwards.
Frequently Asked Questions
When should I divide Siberian Iris?
Divide clumps in early spring as new growth begins, or after flowering if plants have become overcrowded. Most clumps benefit from division every four to five years.
Why isn’t my Siberian Iris flowering?
The most common causes are too much shade, overcrowded clumps or dry soil during the growing season. Plants flower best in full sun with consistently moist soil.
Can Siberian Iris grow in wet soil?
Yes. One of the great advantages of Siberian Iris is their ability to tolerate wet conditions that would cause many other Iris to struggle.
Are Siberian Iris evergreen?
The foliage remains attractive through summer before dying back in winter in colder climates. Fresh growth emerges again in spring.
Other Iris of interest
- Algerian Iris
- Bearded Iris
- Dwarf Bearded Iris
- Dutch Iris
- Iris histriodes
- Iris pallida
- Iris pseudacorus
- Iris reticulata
- Japanese Roof Iris
- Louisiana Iris
- Pacific Coast Iris
- Spuria Iris
- Japanese Iris
- Species Iris
- Iris plants for sale
Where To Buy Siberian Iris
365 Lighthouse Rd Wynyard. TAS 7325
PH 03 6442 2012
email to: [email protected]
www.vdqbulbs.com.au
Little Hampton, Vic 345
"Mail order nursery specialising in cottage garden perennials, flowering shrubs, Trilliums, Hostas and Pacific Coast Iris. Flat rate express postage - Except WA & TAS"
www.botanicaltreasures.com
357 Monbulk Road SILVAN VIC 3795
Guaranteed "garden worthy" bulbs, plants and perennials. Visit the website to browse our large range of daffodils or request the latest free catalogue.
www.tesselaar.net.au