Helianthus Shock-o-Lat

How to grow sunflowers

All you need to know about growing sunflowers, in our detailed Grow Guide.

A table displaying which months are best to sow, plant and harvest.
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Sow
Sow

Do not Sow in January

Do not Sow in February

Do Sow in March

Do Sow in April

Do Sow in May

Do not Sow in June

Do not Sow in July

Do not Sow in August

Do not Sow in September

Do not Sow in October

Do not Sow in November

Do not Sow in December

Plant
Plant

Do not Plant in January

Do not Plant in February

Do not Plant in March

Do Plant in April

Do Plant in May

Do Plant in June

Do not Plant in July

Do not Plant in August

Do not Plant in September

Do not Plant in October

Do not Plant in November

Do not Plant in December

Flowers
Flowers

Plant does not flower in January

Plant does not flower in February

Plant does not flower in March

Plant does not flower in April

Plant does not flower in May

Plant does flower in June

Plant does flower in July

Plant does flower in August

Plant does flower in September

Plant does not flower in October

Plant does not flower in November

Plant does not flower in December

Cut back
Cut back

Do not Cut back in January

Do not Cut back in February

Do not Cut back in March

Do not Cut back in April

Do not Cut back in May

Do not Cut back in June

Do not Cut back in July

Do not Cut back in August

Do not Cut back in September

Do Cut back in October

Do Cut back in November

Do not Cut back in December

The sunflower is one of the nation’s best-loved flowers. Although most sunflower varieties have yellow flowers, sunflowers do have rusty red, green and white flowering forms.

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Sunflowers are perfect for growing as part of a race with friends, family and neighbours, to see who can grow the tallest sun flower. They’re also ideal for growing with children, who love growing plants taller than them.

How to grow sunflowers

Choose your variety carefully as some sunflowers will grow 50cm, while others grow over 3m. Sow seeds in pots from April and plant out when all risk of frost has passed. Prepare the soil well and add plenty of organic matter to the planting hole. Keep your sunflowers well watered and feed weekly to encourage them to grow tall. You may need to stake some of the taller varieties.

More on growing sunflowers:

Find out all you ned to know about growing sunflowers, below.


Where to grow sunflowers

How to grow sunflowers - where to grow sunflowers
How to grow sunflowers – where to grow sunflowers

Sunflowers need sun. They do best in fertile soil in a sheltered spot, but will also do well in containers. However, if you want your sunflower to grow really tall, it’s best to plant it in the ground.


How to plant sunflowers

How to grow sunflowers - how to plant sunflowers
How to grow sunflowers – how to plant sunflowers

Sow sunflower seeds into individual pots of peat-free, multi-purpose compost in April. Sow one seed per 7.5cm pot. Push the seed 1.5cm into the compost and water in. Cover pots with a clear plastic bag and place in a cool but bright place.

Watch Monty Don sow sunflower seed as part of his giant sunflower trial, in this clip from Gardeners’ World:

After the sunflowers have germinated, keep them well-watered until they’re ready to plant out at the end of May. Prepare soil by removing weeds and add plenty of organic matter. Plant the sunflowers at the same depth they were in the pot. Water well and stake plants with a bamboo cane or similar.

Here, Monty plants out his sunflowers and explains how to stake them:


Caring for sunflowers

Annual sunflowers need plenty of water. Feed them with tomato feed just before flowering. Don’t allow plants to dry out as very tall varieties will have a job to recover.

Very tall varieties may need the support of a garden cane – especially when growing in an exposed position.

After flowering, leave the faded flower head intact so the birds can feast on the seeds. Once they have eaten their fill pull out the entire plant and put it on the compost heap.

Find out which sunflower fares best in Monty’s giant sunflower trial update:


Growing sunflowers: problem solving

How to grow sunflowers - sunflower seedlings
How to grow sunflowers – sunflower seedlings

Sunflowers are generally trouble free but young seedlings are susceptible to slug and snail damage. If you are only growing a few sunflowers, make sure you let them grow quite tall before planting out. You could also use wildlife-friendly slug pellets or copper tape to deter them.


Sunflowers to grow

How to grow sunflowers - sunflower 'Russian Giant'
How to grow sunflowers – sunflower ‘Russian Giant’
  • Helianthus annuus ‘Russian Giant’ – this is a real cracking annual with flower stems reaching as high as 3m. A traditional yellow flower from July-September. A real race winner!
  • Helianthus annuus ‘Velvet Queen’ – coppery red flowers from July to September from this popular annual. Reaches 1.8m
  • Helianthus annuus ‘Teddy Bear’ – an annual with large pom-poms of double yellow flowers from July to September. Height 50cm
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  • Helianthus giganteus – large single yellow blooms held on 2m long stems from June to August