How to Grow Sunflowers UK

On this page
  1. Sunflower (Helianthus annuus)
  2. When to Plant Sunflowers in the UK
  3. Quick Facts
  4. At a Glance
  5. Soil & Growing Conditions
  6. Growth Stages
  7. Harvest & Storage
  8. Diseases
  9. Pests
  10. Sunflower, From Bud to Harvested Seed Head
  11. Plan your Sunflowers planting
  12. Growing Sunflower in another region
  13. References
  14. Frequently Asked Questions

In the UK, sunflowers go in the ground late March to late May.

Timing is the decision that matters most in the UK: sowing late March, and that same window applies across all 4 regions covered here.

The short answer

Plant
Late March to late May
Site
6+ hours of sun, soil pH 6–7.5
Biggest risk
White mold

Core growing advice on this page is checked against named horticultural sources — see References.

Sunflower (Helianthus annuus)

A closed sunflower bud before flowering — “2014-365-191 Trying to Show the Sun (14623052374)” by cogdogblog is licensed under CC BY 2.0.

6 sources cited · Verified

When to Plant Sunflowers in the UK

When to plant sunflowers in the UK: in Southern England, sow late March to late May. Find your area in the table below.

A closed sunflower bud before flowering
A closed sunflower bud before flowering. Photo: “2014-365-191 Trying to Show the Sun (14623052374)” by cogdogblog, CC BY 2.0.
Region Sow
Southern England late March to late May
Midlands late March to late May
Northern England late March to late May
Scotland late March to late May
Southern England - detail & sources

RHS: sow indoors from late March, or direct outdoors mid-April to May; a single window is applied uniformly across all four sub-regions since the source gives no UK-region-specific gradient.

Midlands - detail & sources

RHS: sow indoors from late March, or direct outdoors mid-April to May; a single window is applied uniformly across all four sub-regions since the source gives no UK-region-specific gradient.

Northern England - detail & sources

RHS: sow indoors from late March, or direct outdoors mid-April to May; a single window is applied uniformly across all four sub-regions since the source gives no UK-region-specific gradient.

Scotland - detail & sources

RHS: sow indoors from late March, or direct outdoors mid-April to May; a single window is applied uniformly across all four sub-regions since the source gives no UK-region-specific gradient.

A page from the UK Vegetable Garden Planner PDF: the crop rotation planner, with a planning grid and four-bed rotation tips

Plan your sunflowers — and the rest of the plot

This page covers sunflowers. For every crop's sowing months on one chart, use the free UK vegetable planting calendar, and browse the UK vegetable growing guides for what else to grow alongside it. When you want the whole season on paper, the UK Vegetable Garden Planner is a printable PDF:

  • Twelve month-by-month sowing and harvest spreads
  • Raised bed, allotment and container layout pages for your own plot
  • A four-year crop rotation planner
  • Seed inventory, sowing log and harvest tracker
See inside the UK Vegetable Garden Planner →

Instant PDF download · reprint every season

Quick Facts

Close-up of a sunflower's large yellow-petalled head
Close-up of a sunflower's large yellow-petalled head. Photo by Maksym Kozlenko, CC BY-SA 4.0.
Factor Value
Soil pH 6 - 7.5
Sunlight 6-6 hours direct sun
Optimal growing temp 17-34°C
Minimum survivable temp -10°C
Drainage Moist but well-drained
Lifecycle annual
Edible parts seeds, petals, young leaves

At a Glance

A field of sunflowers in bloom
A field of sunflowers in bloom. Photo by Andreas Eichler, CC BY-SA 4.0.
Helianthus annuus Sunflower White mold (Sclerotinia… Powdery mildew Slugs Snails DISEASES PESTS

Soil & Growing Conditions

A row of tall sunflower plants in a field
A row of tall sunflower plants in a field. Photo by Maksym Kozlenko, CC BY-SA 4.0.

Soil pH range

6 7.5

Span reflects genuine variation between the cited authorities, not a single agreed figure.

Growth Stages

A closed sunflower bud before flowering
A closed sunflower bud before flowering. Photo: “2014-365-191 Trying to Show the Sun (14623052374)” by cogdogblog, CC BY 2.0.
Stage BBCH Notes
Sowing and germination 0 Sow indoors from late March for a head start, or direct outdoors mid-April to May, in 2cm-deep holes 30cm apart (RHS).
Establishment and staking 1 Thin to about 45cm apart, keeping the strongest plants; place a strong bamboo cane at planting time and tie the stem loosely as it grows, since most varieties need support (RHS).
Rapid growth and flowering 6 Thirsty plants needing consistently moist soil; feed with a potassium-rich fertiliser to encourage flowering; the large yellow-petalled flower head opens through summer (RHS).
Seed ripening and harvest 8 Leave the flower head standing for at least two weeks after flowering so birds can also feed, then cut before they take it all, dry for about a week, and rub over newspaper to release the seed (RHS).

Harvest & Storage

Sunflowers with drooping seed heads ready for harvest
Sunflowers with drooping seed heads ready for harvest. Photo by Alfredo SÁNCHEZ GARZÓN, CC BY-SA 4.0.

When to pick: RHS: sown March-May, flowering in August (annual). NC State: blooms "from July to October"; planted "after the last frost in the spring, and harvested before the first frost in the fall"; mature seedheads indicated by "standing dead flowers" left "into the winter" as a bird-feeding indicator. RHS: for edible seed, "collect some of the seeds from your plants at the end of the season" rather than leaving all seedheads for birds.

Storage

Dry seedheads and store seeds in a cool, dry place

Diseases

A row of tall sunflower plants in a field
A row of tall sunflower plants in a field. Photo by Maksym Kozlenko, CC BY-SA 4.0.
White mold (Sclerotinia stem rot)

Sclerotinia sclerotiorum

Pests

A row of tall sunflower plants in a field
A row of tall sunflower plants in a field. Photo by Maksym Kozlenko, CC BY-SA 4.0.
Slugs

Gastropoda (slugs, various spp.)

Snails

Gastropoda (snails, various spp.)

Plan your Sunflowers planting

When to sow and plant Sunflowers depends on your own frost dates. Check the UK vegetable planting calendar, or the month-by-month guides that cover Sunflowers: December. To work out where it fits in your beds, sketch your plot in the free Garden Layout Planner.

Growing Sunflower in another region

Sowing dates, frost timing and local advice differ by country. Use the guide for where you garden.

Frequently Asked Questions

When should I sow sunflowers in the UK?

In Southern England, from late March. In Scotland, wait until late March. Treat these as a guide rather than a fixed date — the governing rule is to sow only once frost risk has passed and temperatures are reliably warm enough.

When do I sow sunflowers?

Sow late March to late May.

What soil pH do sunflowers need?

A pH of about 6–7.5. That span reflects genuine variation between the authorities we cite rather than a single agreed figure — the References section lists each source's exact range.

What problems affect sunflowers?

Our data links 2 diseases and 2 pests to this crop. See the sections above for each one and how to manage it.

Plan next season before the problems start

Most of the advice on this page comes down to timing and spacing — sowing at the right moment, rotating beds, and giving plants enough airflow. The UK Garden Planner lays your plot out month by month so those decisions are already made before the season starts.

Get the UK Garden Planner →

Instant PDF download · Written for UK growing conditions

SoilCommander Editorial Team — under the guidance of Nitin Sharma, Co-Founder

Every growing guide is checked against RHS, USDA Cooperative Extension, and other named horticultural authorities before publishing. How we check our facts.

How this guide is put together

The growing data on this page — sowing windows, pests, diseases, soil and site requirements — comes from named horticultural sources, listed in References below, checked against RHS and Met Office guidance. An automated pipeline assembles that verified data into the page you're reading: it selects which facts to lead with and builds the surrounding prose and layout. It does not invent a date, a source or a number — where a verified value for a field isn't available, the page leaves it out rather than guessing. A person reviews and publishes each page; nothing goes live unverified.

Vegetable Growing Guides UK

Last verified 2026-09-02

Relevant next steps

Where To Go From Here

Take this crop from reading into a written plan for your own beds.

Keep going

This guide in another region
Top tips for October
  • Plant garlic before hard frosts
  • Protect late salads with fleece
  • Store squash somewhere dry
  • Mulch empty beds
Free Tool
soilcommander.com/pages/vegetable-garden-layout-planner-tool
1 · Shape
2 · Crops
3 · Conditions
4 · Plan
Choose your garden shape
🍅
Bed 1
Tomatoes
🍌
Bed 2
Legumes
🥦
Bed 3
Brassicas
🥕
Bed 4
Roots
🥥
Bed 5
Alliums
🌿
Herbs & More

Free planning tool

Plan your veg garden before you dig a single inch

Sketch your exact plot shape, pick your UK crops, and get a spacing-accurate bed layout with companion pairings, a rotation plan and month-by-month sowing dates — every fact sourced from RHS and Garden Organic.

Garden Layout Planner Tool

Free to use. Nothing to install.

Plan the next step

Use the printable SoilCommander planner for your region to turn this guide into sowing dates, bed layouts and weekly garden tasks.

Get Planner