How to grow: Sunflowers

Few flowers bring as much joy and sunshine to the garden as sunflowers. With their bold blooms, towering stems, and pollinator-friendly faces, they’re a summer favourite for gardeners of all ages — and easier to grow than you might think! Whether you're after classic giants or compact varieties for pots, here’s everything you need to know to grow stunning sunflowers from seed to bloom.

When to Plant Sunflower Seeds

In the UK, sunflower seeds can be sown from April to June, once the risk of frost has passed. You can start them indoors in pots in April and plant them out later, or sow directly into the ground in May or June.

Where to Plant Sunflowers

Sunflowers love the sun — it’s in the name! Choose a bright, sunny spot with well-drained soil. They’re happiest with 6–8 hours of sunlight a day and need shelter from strong winds, especially the taller varieties.

Top Tip: If planting in a windy area, support taller varieties with a cane or stake early on.

How to Sow Sunflower Seeds

1. Prepare the soil by raking it to a fine texture and removing weeds.

2. Sow seeds about 1.5cm deep, spacing them 30cm apart for smaller varieties and 45cm+ for giants.

3. Water gently and keep the soil moist while seeds germinate — usually in 7–14 days.

Caring for Your Sunflowers

• Water regularly, especially during dry spells or if growing in pots.

• Once established, sunflowers are quite drought-tolerant.

• Feed with a general-purpose fertiliser every few weeks for bigger, better blooms.

• Watch out for slugs and snails when the plants are young.

When Will They Bloom?

Depending on when you plant them, sunflowers typically bloom between July and September. The taller varieties can grow over 2 metres high, while dwarf types bloom beautifully in pots and borders.

Pollinator Bonus

Sunflowers are a magnet for bees, butterflies, and even birds later in the season when the seeds mature. Letting the flower heads dry naturally is a great way to feed garden wildlife into autumn.

 

 Popular Varieties to Try:

• ‘Giant Single’ – classic tall sunflower with huge golden blooms

• ‘Teddy Bear’ – fluffy, compact variety ideal for pots

• ‘Velvet Queen’ – deep red-bronze petals for a dramatic twist

• ‘Little Leo’ – perfect for children’s gardens and small spaces

Growing with Kids?

Sunflowers are one of the best plants for children to grow — fast-growing, fun to measure, and perfect for sunny garden projects or competitions!