Iris 'Black Knight' (Iris 'Black Knight')

Botanical name

Iris 'Black Knight'

Other names

Gold-marked iris 'Black Knight', Iris 'Black Knight', Iris chrysographes 'Black Knight'

Genus

Iris Iris

Variety or Cultivar

'Black Knight' _ 'Black Knight' is a clump-forming, rhizomatous perennial with upright, strap-like, grey-green leaves and, in summer, dark purple flowers with gold streaks on the falls.

Foliage

Deciduous

Fragrance

Flowers are fragrant

Habit

Clump-forming, Erect

Toxicity

Ingestion may cause severe discomfort.

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Colour

Flower

Black, Golden-yellow, Dark-purple in Summer

Foliage

Grey-green in Spring; Grey-green in Summer; Grey-green in Autumn

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How to care

Watch out for

Specific pests

Slugs , Snails , Thrips

Specific diseases

Grey mould , Iris rhizome rot

General care

Pruning

Cut back after flowering to keep tidy

Propagation

Divide every 3-4 years for best blooms.

Propagation methods

Division

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Monthly care advice

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Where to grow

Iris 'Black Knight' (Iris 'Black Knight') will reach a height of 0.5m and a spread of 0.5m after 2-5 years.

Suggested uses

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

Cultivation

Plant in moist, but well-drained, neutral to slightly alkaline loam in full sun or partial shade. Mulch in spring.

Soil type

Loamy, Clay

Soil drainage

Well-drained, Moist but well-drained

Soil pH

Alkaline, Neutral

Light

Partial Shade, Full Sun

Aspect

South, West

Exposure

Sheltered

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

Tender in frost (H3)

USDA zones

Zone 10, Zone 9, Zone 8, Zone 7, Zone 6, Zone 5, Zone 4, Zone 3

Defra's Risk register #1

Plant name

Iris 'Black Knight' (Iris 'Black Knight')

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 'Black Knight' (Iris 'Black Knight')

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/