Iris 'Moon Silk' (Sib)

RHS Plant Profile
Siberian iris 'Moon Silk'
Herbaceous Perennial

A rhizomatous, clump-forming, herbaceous perennial with upright, strap-like, dark green leaves and erect stems, growing to 1m tall, bearing elegant flowers with green veined white upper petals, known as standards, and pale yellow lower petals, known as falls, that eventually fade to white

Position

Full sun, Partial shade

Soil Types

Chalk, Loam, Clay, Sand

Max Height

0.5-1 metres

Max Spread

0.5-1 metres

Size

Time to Maturity
2–5 years
Max Spread
0.5-1 metres
Max Height
0.5-1 metres

Growing Conditions

Chalk Loam Clay Sand
Moisture
Moist but well–drained
pH
Acid or Neutral

Position

Full sun Partial shade
Aspect
East–facing or South–facing or West–facing
Exposure
Exposed or Sheltered
Hardiness
H7

Colour & Scent

Season Stem Flower Foliage Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family
Iridaceae
Native to GB/Ireland
No
Foliage
Deciduous
Habit
Clump forming, Columnar upright
Potentially harmful
Harmful if eaten. Wear gloves and other protective equipment when handling. Pets: Harmful if eaten. For further information and contact numbers regarding pets, see the HTA guide to potentially harmful plants
Genus
Iris may be rhizomatous or bulbous perennials, with narrow leaves and erect stems bearing flowers with 3 large spreading or pendent fall petals, alternating with 3 erect, often smaller, standard petals, in late winter, spring or early summer
Name Status
Accepted
Horticultural Group
Sibirica irises are rhizomatous perennials, to 1.2m tall, with narrow leaves and erect stems bearing up to 5 beardless flowers 6-7cm wide in early summer. Form and colour vary considerably among cultivars

How to Grow

Cultivation

Grow in any moist but not waterlogged, neutral to slightly acidic soil in full sun or partial shade. In drier soils, dig in well-rotted manure before planting and apply as a mulch each spring

Propagation

Propagate by division of the rhizome shortly from mid-summer to early autumn. See dividing irises

Suggested planting locations and garden types

  • Coastal
  • City and courtyard gardens
  • Cottage and informal garden
  • Low Maintenance
  • Cut flowers
  • Flower borders and beds
  • Garden edging
  • Wall side borders

Pruning

Cut back old flower stems after flowering and remove dying foliage in autumn

Pests

May be susceptible to slugs and snails

Diseases

May be susceptible to aphid-borne viruses, bacterial soft rot and grey moulds; see Iris diseases