Plant Information
Iris sibirica Butter Sugar
Scientific Name: Iris sibirica
Common Name: Siberian Iris
Hardiness Zone: 3a - 9b
Hardiness Degree: -40°F (-40.0°C)
Blooming Season: Spring, Late Spring
Plant Habit: Columnar
Characteristics: Shade Tolerant
Water: Heavy
Fertilize: None or when needed only
Spacing: 11 - 15" (28 - 38cm)
Height: 24 - 28" (61 - 71cm)
Width: 20 - 24" (51 - 61cm)
Exposure: Sun
General Information: Creamy standards and butter-yellow falls. Reblooms.
Creamy standards and butter-yellow falls. Reblooms. Medium to broad, pendent or semi-flaring falls and medium to long, upright standards. Signals on blue and pink flowers often consist of showy, intricately marked yellow and white patterns. Siberian Irises have a useful flowering period, between Spring and Summer-flowering perennials. Best in sun or light shade and moisture-retentive, slightly acidic soil.