Interflora’s guide to sunflowers

iStock_000008452249XSmallTo kick off the sunflower fortnight we wanted to provide you with this comprehensive guide to sunflowers including their origins, how to grow them and lots more….

Sunflowers (helianthus annuus) are one of the brightest flowers around and to most are synonymous with summer. There are the huge flowers, of course – which grow to above 3.5m tall – but also the dwarf varieties that grow to only 1m, sometimes even shorter.

DennisWhichever variety you choose to grow you’ll be rewarded with bright green leaves, yellow petals and a large brown middle. We talked to one of our expert florists – Dennis van Wonderen of van Wonderen Flowers in Sunbury-on-Thames – to find out more about sunflowers.


SunflowerSunflowers are native to the central Americas and were domesticated there around 2,600BC. At first they were used to provide food to those growing them, but there is evidence that the native Americans also used them for medicinal purposes.

They were brought to Europe in the 14th century. The plant quickly became a popular source of food and was grown across Europe. In the 18th century, when the plant was beginning to be grown in Russia, it became a popular source of cooking oil, especially among members of the church as it was the only oil not to be forbidden during Lent.


This is where a plant changes its orientation to follow the sun. Sunflowers are famous for this.

iStock_000012660845XSmallDennis van Wonderen says: “Sunflowers follow the sun once they’re open. If you have a field full of sunflowers and the sun comes up on the left then they’ll all be facing left in the morning. By the end of the day when the sun has gone over the field, they’ll all have moved and their heads will be facing right.

“It’s particularly amazing to see the huge fields of sunflowers in France as you really get a sense of how much they move.”


Field of sunflowers.There are many varieties of sunflowers. The petal colour can vary from bright yellow to a deep red and the centre colour varies from black to green.

The largest sunflower ever recorded was 12m tall. Others from the same batch of seeds grew to around 8m.

The Giant Grey Stripe is a variety of sunflower known to grow to 4.5m. The heads grow to approximately 38cm and they provide numerous seeds for you and the birds.

Orange Sun blooms provide huge double-faced blooms and can grow to 1.8m. Italian Whites have white or very pale yellow blooms and grow to around 2m.

iStock_000011925577XSmallThe Mammoth, as the name would suggest, is a huge sunflower variety with bright blooms that creates loads of seeds. Autumn Beauty has multiple flowers per plant in a deep orange. They grow to around 1.5m.

Moonbright sunflowers are lemon yellow with huge, dark centres. They also have big leaves and grow to between 1m and 1.5m. The Moulin Rouge is a rather unusual sunflower as it has dark red petals and a black centre. It can grow to between 1m and 2.5m.

And the dwarf sunflower Ring of Fire grows to just 1m tall and has yellow petals, which change to orange the closer they get to the centre.Sunflower 3

Dennis van Wonderen is a fan of the Helianthus Sunrich Orange. “It’s a traditional sunflower and it’s got that golden yellow colour. If you want to grow a smaller one there’s a variety called Munchkin and it’s pollen free so has a longer lifespan. It’s great in a pot or as a border plant and the centre of it is green rather than brown.”

These are just a few of the varieties of sunflower out there. There are many others, some good for growing tall and some good for a flash of colour in your garden borders.

Sunflower growing competitions

iStock_000012670292XSmallThese are held in back gardens and village fêtes on a yearly basis. A family competition to see who can grow the tallest sunflower is a great way to get kids out into the garden.

There have to be some rules, of course. Limit the number of seeds each family member can plant – five is usually a good number. Then let each person use any means possible to make their sunflower the tallest – as long as they don’t interfere with anyone else’s.

Autumn festivals, along with the largest pumpkin competitions, also give out prizes for those who can grow the tallest sunflower. The most popular giant sunflower varieties are the Mammoth, American Giant and Skyscraper.

Dennis van Wonderen says: “A really huge variety is the Mongolian Giant, which can grow up to 4.5m in height. The Kong gets up to 4m as well; it has lots of leaves at the bottom and only one flower at the top.

iStock_000004564681XSmall“In Sunbury-on-Thames we have a sunflower competition. The local residents association came up with the competition to grow the biggest one and I’ve been chosen to judge.

“There are about 70 houses in the village growing the sunflowers. We gave the residents the seeds in return for a donation to a charity and I’m looking forward to the end of July, when we’ll be judging them.”

Dennis has some advice for those of you trying to grow the tallest sunflower. “Grow them direct into ground, not in a pot, and plant them next to a fence or by the house as when they start growing they’re really fragile in the wind.”

How to grow sunflowers

iStock_000001549620XSmallMost sunflowers are annuals and these are the ones you want to grow if you are looking to add a splash of colour to your garden. Perennials are a little more difficult, as they can be quite invasive and harder to maintain than annual sunflowers.

Dennis van Wonderen says: “Anyone can grow sunflowers. You can get them from seed and you sow them during the spring. You can plant them either in the open ground or in a pot.”

Annual sunflowers are generally quite easy to grow. They require moist, well-drained soil in a spot where they get lots of sun – at least six hours a day.

iStock_000011688608XSmall“It’s important to keep them well fed and watered and it’s vital that you plant them on a sunny site. The optimum temperature for them is 20 degrees Celcius,” Dennis adds.

Make sure you leave adequate spaces between your seeds – remember some of these plants can grown to enormous heights and therefore need strong roots and a thick stem. Dennis van Wonderen says: “If you’re planting larger varieties, so ones that will end up with heads of about 40cm in diameter, then you’ll need to plant them abut 15cm apart to ensure they have enough room. You’ll need to lightly cover the seeds with soil and keep them well watered.”

Because of their hardiness and resistance to disease, sunflowers are one of the easiest plants to grow and therefore are a great way to introduce kids into gardening.


iStock_000006805469XSmallIt is said that the Incas worshipped the sunflower as an image of their sun god and that tiny carvings of sunflowers have been found in the ruins of Incan sun temples. It is also said that Incan priestesses wore sunflower headdresses.

Sunflowers were a very popular subject for the Impressionists. Easily the most famous painting of sunflowers was, of course, Vincent Van Gogh’s piece entitled ‘Sunflowers’.

SG1055The sunflower is also the state flower for Kansas, the national flower of Ukraine and the city flower of Kitakyüshü in Japan.

The vegan society uses the sunflower in its logo as the plant provides vegan friendly foods such as its seeds and the oil that comes from them.

In a bouquet, cut sunflowers are one of the happiest gifts someone can receive. They announce the coming of what all hope will be a long lasting summer. Traditionally they mean loyalty and longevity. Sunflowers have a warming and comfortable quality about them, which makes them a very popular cut flower.

Sunflowers as a crop

Sunflower Seeds on Wooden SpoonCertain varieties of sunflowers are grown all across the world to provide us with sunflower seeds as a snack food and also to provide the seeds to turn into sunflower oil, a cheaper alternative to olive oil.

If you want to grow sunflowers to get seeds for yourself or the birds then firstly you need to choose a variety that is a good producer of seeds. Try the Giant Grey Stripe. Once the petals begin to turn brown and the backs of the heads yellow you can harvest your sunflower. You can leave it longer but birds love sunflower seeds too.

Sunflower oil bottleCut the head off leaving some of the stalk still attached. Hang it in a dry, well-ventilated room and cover it with cheesecloth to catch any falling seeds. When you can easily rub the seeds from the centre your sunflower is fully dried and your seeds ready to be eaten, roasted or given to pets, such as hamsters and mice.

You can leave the heads to dry on the stalk but you should cover them to protect them from birds. Leaving a drying head uncovered outside is a great way to attract birds as they make great bird feeders.

For more information on Dennis and van Wonderen Flowers visit or telephone 01932 761071.