When to plant sunflower seeds for sunny blooms to brighten your garden this summer

Experts advise what is the best month to sow your sunflower seeds in the UK for a thriving and vibrant plant

A sunflower plant
(Image credit: Future PLC/Georgia Burns)

Sunflowers are loved for their sunny and joy-inducing blooms, guaranteed to brighten up your garden. After all, it’s in their name. But if you want a set of sunflowers decorating your garden this summer, then you need to know when to plant sunflower seeds.

If you already have some of these happy blooms in your borders, then you can learn how to propagate sunflowers from cuttings. But if you’re starting from scratch, a pack of sunflower seeds is your best bet.

But the timing of planting is crucial as sunflowers are warmth-loving plants. And if there is something they can’t stand, it’s low temperatures. So just keep that in mind when deciding when you’re going to plant your seeds. So don't go rushing your seeds into seedling stays just yet, this is the optimal time that gardening experts recommend planting sunflower seeds.

A collection of plant seeds

(Image credit: Future PLC)

When to plant sunflower seeds

Unlike the best time when to plant peonies, which need to be planted in autumn in order to start flowering in late spring, sunflower seeds are best to be planted in spring as they are not hardy enough to survive through winter.

‘If you're sowing your sunflower seeds into the ground, then you should plant them in late April or May,’ says Steve Chilton, garden expert at LeisureBench. ‘This is because the risk of frost has passed and the soil has warmed up. Sunflowers are warm-season plants that thrive in temperatures around 20°C-25°C.’

A sunflower plant

(Image credit: Future PLC/Camilla Reynolds)
Steve Chilton portrait
Steve Chilton

Steve is a passionate and knowledgeable garden expert with several years of experience within the field. As the director of LeisureBench, an industry-leading garden furniture company, Steve has developed strong expertise for all things nature and plants. 

But if you are planting your seeds in pots rather than the ground, you can do so a month earlier. ‘If you're sowing your sunflower seeds in pots, then you can plant them in late March or April,’ Steve adds.

From there, sunflowers don’t take long to fully mature and flower as they are one of the best flowering plants to grow in August.

A bunch of sunflowers in a vase on a garden table

(Image credit: Future PLC/Camilla Reynolds)

Where to buy sunflower seeds


How long do sunflowers take to grow from seed?

‘Sunflowers typically grow and flower within 70 to 100 days after planting,’ says Petar Ivanov, gardening expert from Fantastic Gardeners.

Steve adds, ‘Sunflowers will flower most likely in August, and they have pretty rapid growth. The warmer the weather, generally the quicker a sunflower will grow.’

A sunflower plant

(Image credit: Future PLC/Charlotte Coward-Williams)
Petar Ivanov portrait
Petar Ivanov

Petar Ivanov is one of the company's top-performing experts and manages over six teams of gardeners, delivering stunning landscape results and fostering a deep connection with nature through his work.

Should I put sunflower seeds in water before planting?

Soaking sunflower seeds prior to planting is not absolutely necessary.

‘It's actually advised to plant them directly in well-prepared soil and, afterwards, water them well to maintain consistent soil hydration for successful germination,’ Petar says.

However, there are times when soaking your seeds might help, Steve says.

‘If you plant your sunflower seeds out of season, then it might improve germination rates, as when you soak them, you help soften the seed coat which therefore prompts the germination process,’ he explains.

But as long as your planting soil has adequate moisture, the temperature is at least 20°C and the plant receives enough sunlight, your sunflowers should be perfectly healthy and blooming come summer.

Sara Hesikova
News Writer

Sara Hesikova has been Ideal Home’s News Writer since July 2023, bringing the Ideal Home’s readership breaking news stories from the world of home and interiors. Graduating from London College of Fashion with a bachelor’s degree in fashion journalism in 2016, she got her start in niche fashion and lifestyle magazines like Glass and Alvar as a writer and editor before making the leap into interiors. She feels the two are intrinsically connected - if someone puts an effort into what they wear, they most likely also care about what they surround themselves with.