Panicum virgatum (Switch grass)

Botanical name

Panicum virgatum

Other names

Switch grass

Genus

Panicum Panicum

Species

P. virgatum - P. virgatum is a narrowly upright, rhizomatous, deciduous, perennial grass forming clumps of purple-flushed, mid-green stems bearing upright, flat, linear, mid-green leaves, turning yellow in autumn and light brown in winter. Broad, pendent panicles of tiny, purple-green flower spikelets bloom in early autumn.

Foliage

Deciduous

Habit

Clump-forming, Upright

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Colour

Flower

Purple, Flushed green in Autumn

Foliage

Mid-green, Flushed purple in Spring; Mid-green, Flushed purple in Summer; Yellow-brown in Winter

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How to care

Watch out for

Pests

Generally pest free

Diseases

Generally disease free

General care

Pruning

Cut back in late winter or early spring.

Propagation methods

Division

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Monthly care advice

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Where to grow

Panicum virgatum (Switch grass) will reach a height of 1m and a spread of 0.75m after 2-5 years.

Suggested uses

Architectural, Beds and borders, City, Cottage/Informal, Flower Arranging, Low Maintenance, Prairie planting

Cultivation

Grow in full sun in moderately fertile, well-drained or moist but well-drained soil. May flop in fertile soils. Primarily clump-forming but may slowly spread by creeping rhizomes.

Soil type

Chalky, Clay, Loamy, Sandy (will tolerate most soil types)

Soil drainage

Moist but well-drained, 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

Panicum virgatum (Switch grass)

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

Panicum virgatum (Switch grass)

Common pest name

Corn borer; Corn moth; European corn borer; European maize borer; European stalk borer; Maize pyralid

Scientific pest name

Ostrinia nubilalis

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

Polyphagous boring pest present in the UK since the 1930’s. A maize-affecting race was detected for the first time in 2010. Industry may wish to monitor for its presence and mitigate against impacts.

Defra's Risk register #3

Plant name

Panicum virgatum (Switch grass)

Common pest name

Rice leaf nematode; Strawberry crimp disease nematode; White tip nematode; White tip nematode of rice

Scientific pest name

Aphelenchoides besseyi

Type

Nematode

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

Damaging nematode affecting rice crops and strawberry production in warmer climates; could potentially present a threat to strawberry production and ornamental production in protected environments. But modern production practices seem to reduce likelihood of impacts. Pest is also regulated at EU level; which reduces likelihood of entry.

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/