Siberian iris Iris sibirica
Siberian iris (Iris sibirica) is a deciduous perennial flowering plant in the Iridaceae family, native to Central and eastern Europe to Russia. It grows 70 cm–1.2 m (28 in–3.9 ft) tall and 50–80 cm (20–31 in) wide, wants full sun and moderate water, and is hardy to about -34 °C (-29 °F). Space plants about 60 cm (24 in) apart.
Plan Siberian iris in your garden →
Free. Draw your beds, then watch it grow through the year in 2D and 3D.
Siberian iris at a glance
| Type | Perennial flowering plant, deciduous |
|---|---|
| Family | Iridaceae |
| Mature height | 70 cm–1.2 m (28 in–3.9 ft) |
| Mature spread | 50–80 cm (20–31 in) |
| Spacing | 60 cm (24 in) centre to centre |
| Sun | Full sun, at least 6 h of direct sun a day |
| Water | Moderate; drought tolerance low, waterlogging tolerance moderate |
| Soil pH | 5.5–7.5 |
| Cold hardiness | About -34 °C (-29 °F) once established (roughly USDA zone 4) |
| Heat stress | Likely above about 30 °C (86 °F) |
| Flowering | from about May for 2–4 weeks (northern hemisphere; later in cold climates, earlier in warm ones) |
| Wind tolerance | Moderate |
| Pollinator value | Moderate |
| Edible | Not grown as food |
| Native to | Central and eastern Europe to Russia |
| Common in gardens of | 🇷🇺 Russia, 🇩🇪 Germany, 🇺🇸 United States |
Is Siberian iris toxic?
- People: mildly toxic
- Cats: moderately toxic
- Dogs: moderately toxic
- Parts: rhizomes, leaves
Rhizomes contain irritant glycosides that cause drooling, vomiting and diarrhoea.
If a child or pet may have eaten part of a plant, call a poison centre or vet straight away.
Companion planting: what to grow with Siberian iris
No well-documented helpful pairing. Group it with plants that like full sun and moderate water.
See Siberian iris in a botanical garden
It grows in these sample gardens, which you can walk through in 3D:
- Monet’s gardens at Giverny (24 plants)
- Kew: glasshouses and rock garden (10 plants)
- Riverside botanical garden (26 plants)
Questions about Siberian iris
- How far apart should I plant Siberian iris?
- About 60 cm (24 in) apart, centre to centre. A mature plant spreads 50–80 cm (20–31 in).
- Does Siberian iris need full sun?
- Full sun: at least 6 hours of direct sun a day.
- How much water does Siberian iris need?
- Moderate water. Drought tolerance is low and waterlogging tolerance moderate.
- How cold-hardy is Siberian iris?
- It tolerates about -34 °C (-29 °F) once established, roughly USDA zone 4.
- When does Siberian iris flower?
- From about May for 2–4 weeks (northern hemisphere; later in cold climates, earlier in warm ones).
- Is Siberian iris poisonous to cats and dogs?
- For cats it is moderately toxic; for dogs moderately toxic; for people mildly toxic. Rhizomes contain irritant glycosides that cause drooling, vomiting and diarrhoea.
- What grows well with Siberian iris?
- There is no well-documented companion pairing for Siberian iris. Group it with plants that like the same sun (full sun) and water (moderate).
Sources and evidence
Evidence grade B (B: extension service or peer-reviewed).
- RHS Plant Finder, Royal Horticultural Society
- Missouri Botanical Garden Plant Finder, Missouri Botanical Garden
- ASPCA Toxic and Non-Toxic Plant List, ASPCA
Notes and assumptions
- Typical garden-form values; cultivars and local conditions differ.
- Tolerates damp soil; forms dense clumps that are divided every 4-6 years.
Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.
Related plants
- Bearded iris Iris germanica
- Japanese iris Iris ensata
- Dutch crocus Crocus vernus
- Gladiolus Gladiolus x hortulanus
- Freesia Freesia refracta hybrids
- Montbretia (crocosmia) Crocosmia x crocosmiiflora
- African iris Dietes grandiflora
- Bugle lily (watsonia) Watsonia borbonica