When to plant Sunflowers in London

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

Calibrated to London · last frost ≈ 4 Apr

Sow indoors February to March, plant out April to May, harvest July to November. Frost risk November to April.
ActivityJanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember
Sow indoorsNoYesYesNoNoNoNoNoNoNoNoNo
Plant outNoNoNoYesYesNoNoNoNoNoNoNo
HarvestNoNoNoNoNoNoYesYesYesYesYesNo

Growing guide

What to do through the growing season

  1. 01

    Sow Seeds Indoors

    28 Feb to 14 Mar

    Sow seeds around 28th February - 14th March in individual small pots or deep modules. Cover with of compost, keep them in bright light, and keep the compost just moist while they germinate.

  2. 02

    Harden Off Seedlings

    4 Apr to 18 Apr

    From 4th April to 18th April, move seedlings outside for longer spells each day so they adjust to wind and sun. Keep them sheltered from cold nights and check the compost so the roots do not dry out.

  3. 03

    Plant Out

    18 Apr to 2 May

    Plant out from 18th 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

    2 May to 27 Jun Dates as each sowing reaches this stage

    From 2nd May to 27th 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

    4 Jul to 10 Nov Dates as each sowing reaches this stage

    From 4th July to 10th November, deadhead branching varieties so they keep flowering. For single-stemmed sunflowers, cut the flower for indoor display or leave the head to ripen for seed. Water during dry spells.

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.