Iris missouriensis (Missouri flag)

Botanical name

Iris missouriensis

Other names

Missouri flag, Iris montana, Iris tolmeiana, Western blue flag, Rocky Mountain iris, Wild iris, Wild blue iris

Genus

Iris Iris

Species

I. missouriensis - I. missouriensis is a variable, spreading, rhizomatous, deciduous perennial with strap-shaped, erect to arching, dark blue-green leaves and, in summer, slender, branched stems bearing flowers with short, blue to lavender standards and paler falls with dark purple veins.

Foliage

Deciduous

Habit

Erect flower stem, Clump-forming, Arching

Toxicity

Ingestion may cause severe discomfort.

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Colour

Flower

Blue, Lavender, Veined in Summer

Foliage

Blue-green in Spring; Blue-green in Summer

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How to care

Watch out for

Specific pests

Snails , Slugs , Thrips

Specific diseases

Grey mould

General care

Pruning

Remove faded or dead foliage in autumn. Cut back spent flower stems.

Propagation methods

Division

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Monthly care advice

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Where to grow

Iris missouriensis (Missouri flag) will reach a height of 0.5m and a spread of 0.3m after 2-5 years.

Suggested uses

Beds and borders, City, Coastal, Cottage/Informal, Flower Arranging, Wallside and trellises, Waterside

Cultivation

Grow in fertile, well-drained, acid to neutral soil in full sun or partial shade. Tolerates slightly alkaline conditions. Plant in spring.

Soil type

Loamy

Soil drainage

Well-drained

Soil pH

Acid, Neutral

Light

Partial Shade, Full Sun

Aspect

South, East, 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, Zone 4, Zone 3

Defra's Risk register #1

Plant name

Iris missouriensis (Missouri flag)

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 missouriensis (Missouri flag)

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/