Iris laevigata 'Alba' (Japanese iris 'Alba')

Botanical name

Iris laevigata 'Alba'

Other names

Japanese iris 'Alba', Smooth iris 'Alba', White Japanese iris

Genus

Iris Iris

Variety or Cultivar

'Alba' _ 'Alba' is a herbaceous perennial with an erect, clump-forming habit, and pale green, arching foliage with black watermarks in the veins. In early to mid summer it bears white flowers, four to a stem.

Foliage

Deciduous

Habit

Clump-forming, Erect

Toxicity

Ingestion may cause severe discomfort.

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Colour

Flower

Blue in Summer

Foliage

Green in Spring; Green in Summer

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How to care

Watch out for

Specific pests

Aphids , Caterpillars , Slugs

Diseases

May be subject to a virus.

Specific diseases

Grey mould , Iris rhizome rot

General care

Pruning

Flower stems can be cut down after flowering.

Propagation

Divide rhizomes after the plant has finished flowering, approximately every 3 years.

Propagation methods

Division

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Monthly care advice

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Where to grow

Iris laevigata 'Alba' (Japanese iris 'Alba') will reach a height of 0.6m and a spread of 0.5m after 2-5 years.

Suggested uses

City, Beds and borders, Cottage/Informal, Waterside

Cultivation

Grow in moist or wet, deep, acid to neutral soil, preferably at pond or stream margins. Will tolerate slightly alkaline conditions.

Soil type

Clay, Loamy

Soil drainage

Boggy damp conditions, Moisture-retentive

Soil pH

Acid, Neutral

Light

Full Sun

Aspect

South, West

Exposure

Exposed, Sheltered

UK hardiness Note: We are working to update our ratings. Thanks for your patience.

Hardy (H4)

USDA zones

Zone 8, Zone 7, Zone 6, Zone 5

Defra's Risk register #1

Plant name

Iris laevigata 'Alba' (Japanese iris 'Alba')

Common pest name

Red rice root aphid; Rice root aphid

Scientific pest name

Rhopalosiphum rufiabdominalis

Type

Insect

Current status in UK

Absent

Likelihood to spread to UK (1 is very low - 5 is very high)

3

Impact (1 is very low - 5 is very high)

3

General biosecurity comments

Potentially significant glasshouse pest; growers should monitor for its presence. Routine aphid control should be effective in mitigating risk.

Defra's Risk register #2

Plant name

Iris laevigata 'Alba' (Japanese iris 'Alba')

Common pest name

common blossom thrips; cotton bud thrips; tomato thrips

Scientific pest name

Frankliniella schultzei

Type

Insect

Current status in UK

Absent

Likelihood to spread to UK (1 is very low - 5 is very high)

2

Impact (1 is very low - 5 is very high)

3

General biosecurity comments

Polyphagous glasshouse pest; present in many countries; single finding in UK.

About this section

Our plants are under greater threat than ever before. There is increasing movement of plants and other material traded from an increasing variety of sources. This increases the chances of exotic pests arriving with imported goods and travellers, as well as by natural means. Shoot is working with Defra to help members to do their part in preventing the introduction and spread of invasive risks.

Traveling or importing plants? Please read "Don't risk it" advice here

Suspected outbreak? Click here for contact details to report to the relevant authority.

Date updated: 7^th March 2019 For more information visit: https://planthealthportal.defra.gov.uk/