Allium stellatum (Prairie onion)

Botanical name

Allium stellatum

Other names

Prairie onion, Autumn onion, Fall glade onion, Cliff onion

Genus

Allium Allium

Species

A. stellatum - A. stellatum is an upright, bulbous perennial with flat, linear, aromatic, mid-green basal leaves and slender, erect stems bearing loose umbels of reddish-pink to pale pink flowers from midsummer into early autumn.

Foliage

Deciduous

Habit

Erect flower stem

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Colour

Flower

Reddish pink, Pink in Summer; Reddish pink, Pink in Autumn

Foliage

Mid-green in Spring; Mid-green in Summer

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How to care

Watch out for

Pests

Pest free, may suffer from slugs on new growth.

Specific diseases

Onion rot , Downy mildew

General care

Pruning

No pruning required. If desired, remove leaves only after they have completely died down. Deadhead to prevent unwanted seedlings.

Propagation

Remove offsets in autumn. Sow seed in a cold frame in spring.

Propagation methods

Offsets, Seed

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Monthly care advice

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Where to grow

Allium stellatum (Prairie onion) will reach a height of 0.5m and a spread of 0.3m after 2-5 years.

Suggested uses

Architectural, Beds and borders, Cottage/Informal, Gravel, Prairie planting, Rock, Wildflower

Cultivation

Grow in well-drained, preferably chalky, rocky soil in full sun. Plant bulbs 5-10cm deep in autumn. Tolerates average, moist conditions if competition from taller, more aggressive plants is eliminated. Self-seeds readily.

Soil type

Chalky, Loamy, Sandy

Soil drainage

Well-drained

Soil pH

Acid, Alkaline, Neutral

Light

Full Sun

Aspect

North, 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 9, Zone 8, Zone 7, Zone 6, Zone 5, Zone 4

Defra's Risk register #1

Plant name

Allium stellatum (Prairie onion)

Common pest name

Asain cotton leafworm; Cluster caterpillar; Fall armyworm; Rice cutworm; Taro caterpiller; Tobacco budworm; Tobacco caterpillar; Tobacco cutworm; Tobacco leaf caterpillar

Scientific pest name

Spodoptera litura

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

Regulated pest; frequently intercepted with occasional outbreaks which have been successfully eradicated in the UK.

Defra's Risk register #2

Plant name

Allium stellatum (Prairie onion)

Common pest name

allium leaf miner

Scientific pest name

Phytomyza gymnostoma

Type

Insect

Current status in UK

Present (Limited)

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

3

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

3

General biosecurity comments

Pest of Allium already present in UK and spreading; previous consultation supported awareness raising only; industry should prepare for the event of findings in commercial crops.

Defra's Risk register #3

Plant name

Allium stellatum (Prairie onion)

Common pest name

Sugarbeet webworm; Weevil; Australian tomato; Weevil; vegetable

Scientific pest name

Listroderes costirostris

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

Awareness needs to be maintained due to the risk of entry as a 'hitchhiker' and monitoring of the pest in countries where it is known to be present.

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/