Helianthus annuus (Common sunflower)

Botanical name

Helianthus annuus

Other names

Common sunflower, Comb flower, Golden, Golden flower of Peru, St Bartholomew's star

Genus

Helianthus Helianthus

Species

H. annuus - H. annuus is a vigorous, robust, erect annual with oval to heart-shaped, roughly hairy, toothed, mid- to dark green leaves and, in summer, stout, sturdy stems bearing large, daisy-like, bright yellow flower-heads with dark brown or purple central discs.

Foliage

Deciduous

Habit

Erect

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Colour

Flower

Bright-yellow in Summer

Foliage

Dark-green in Spring; Dark-green in Summer; Dark-green in Autumn

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How to care

Watch out for

Specific pests

Slugs , Snails

Specific diseases

Powdery mildew , Sclerotinia diseases

General care

Pruning

Cut back after flowering. Remove annual at the end of the growing season. May need staking or support.

Propagation

Sow seed in-situ or in pots in spring.

Propagation methods

Seed

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Monthly care advice

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Where to grow

Helianthus annuus (Common sunflower) will reach a height of 5m and a spread of 0.6m after 1 year.

Suggested uses

Architectural, Beds and borders, City, Cottage/Informal, Flower Arranging, Wildlife

Cultivation

Plant in moderately fertile, humus-rich, moist but well-drained, neutral to alkaline soil in full sun. Requires long, hot summers to flower well. Alternatively, sow in late winter with heat.

Soil type

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

Soil drainage

Moist but well-drained, Well-drained

Soil pH

Alkaline, 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 11, Zone 10, Zone 9, Zone 8, Zone 7, Zone 6, Zone 5, Zone 4, Zone 3, Zone 2

Defra's Risk register #1

Plant name

Helianthus annuus (Common sunflower)

Common pest name

African cottom leafworm; Cotton leafworm; Egyptian cotton leafworm; Egyptian cotton worm; Mediterranean climbing cutworm; Meditteranea Brocade; Tobacco cutworm

Scientific pest name

Spodoptera littoralis

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

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

Defra's Risk register #2

Plant name

Helianthus annuus (Common sunflower)

Common pest name

American serpentine leaf miner; chrysanthemum leaf miner

Scientific pest name

Liriomyza trifolii

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

Regulated pest already subject to review at the EU level (2013). Regularly intercepted in the trade.

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/