Sunflowers in Newlyn

Helianthus annuus

Sunflower
Sunflower · Helianthus annuus

Fast-growing half-hardy annual grown for bold summer flowers and edible seeds. Sow under cover or direct outside once the risk of frost has passed, then give plants a sunny, sheltered spot and steady watering while they establish.

180 cm · Full Sun · Moderate Water

Add to garden

Calibrated to Newlyn · last frost ≈ 22 Mar

Sow March to April, plant out April, harvest May to November. Frost risk November to March.
ActivityJanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember
SowNoNoYesYesNoNoNoNoNoNoNoNo
Plant outNoNoNoYesNoNoNoNoNoNoNoNo
HarvestNoNoNoNoYesYesYesYesYesYesYesNo

Growing guide

Step-by-step instructions for growing Sunflower

  1. 01

    Sow Seeds

    1 Mar to 12 Apr

    Sow seeds around 1st March - 12th April in small pots or modules, or direct where they are to flower in mild areas. Sow seeds to a depth of and keep the compost just moist while they germinate.

  2. 02

    Harden Off Seedlings

    29 Mar to 12 Apr

    From 29th March to 12th April, move seedlings outside for longer spells each day so they adjust to wind and sun. Keep them sheltered from hard frost and check the compost so the roots do not dry out.

  3. 03

    Plant Out

    5 Apr to 19 Apr

    Plant out from 5th April once the soil has warmed and the risk of frost has passed. Space plants apart, water them in thoroughly, and use fleece or a cloche if cold nights are still forecast.

  4. 04

    Support Young Plants

    26 Apr to 7 Jun

    From 26th April to 7th June, fit a cane or stake beside tall plants before they become top-heavy. Tie stems loosely with soft twine and keep the base weed-free so the roots can spread.

  5. 05

    Deadhead & Maintenance

    12 May to 29 Nov

    From 12th May to 29th November, remove fading flowers regularly so the plant keeps producing new blooms instead of putting energy into seed. Water during dry spells, and keep picking off spent heads until the autumn frosts slow growth.

Companion plants

Tap a plant to see why it works (or doesn't) with Sunflower.

Good companions

Plants to avoid

Why companion planting matters

Companion planting can deter pests, improve pollination, and make better use of space. Some plants confuse pests or attract beneficial insects; others improve soil or offer shade to neighbours that need it.

Suggested varieties

Popular varieties of Sunflower to consider

Russian Giant

Tall, classic single yellow flowers with large heads for cutting and seed.

Mongolian Giant

A very tall variety with broad leaves and large flower heads, good for a bold display.

Teddy Bear

A dwarf, double-flowered type with soft, shaggy blooms for pots and smaller gardens.

Autumn Beauty

A mixed-colour variety with branching stems and several medium-sized flowers on each plant.

Sunflower guides by town

See how Sunflower timing shifts in other towns with different frost dates.