A Guide to Growing Sunflowers

Sunflowers are one of the most recognizable flowers, as well as being universally loved by experienced gardeners and novices alike. While the most common sunflowers are yellow, they can also be red, green, and white. They can grow as high as two meters, and produce eye-catching flowers that make a great addition to any garden.

Sunflowers flower between 11 and 18 weeks after seeding, and generally bloom from summer through to fall. They’re a relatively low-maintenance flower, which is great for novice gardeners and kids. 

Can I grow sunflowers where I am?

Sunflowers can grow throughout the United States and will bloom throughout the summer. They can also be grown in Europe, Canada, Mexico, and many parts of Central America.

Sunflowers thrive in environments that get between six and eight hours of sunlight every day. Ideal temperatures for sunflowers are between 70 and 78 degrees Fahrenheit, however, they’re hardy flowers so they can survive in various extremes. For example, sunflowers commonly grow in dry, hot conditions found in prairie lands and plains.

How to grow sunflowers

Growing sunflowers is accessible for everyone, whether you have gardening experience or not. They require little maintenance; just good soil, plenty of sun, and occasionally a good drink of water.

Below, we’ll go through everything you need to know to grow showstopping sunflowers at home.

Where to grow sunflowers

Sunflowers need lots of sun, so it’s best to grow them outside. However, they can be grown inside so long as they get at least six hours of sunlight.

You’ll need to sow your sunflower seeds in nutrient-rich soil that drains well. This can be done either in the ground or a pot (at least 5 inches), but because they get so tall - and top-heavy when they bloom - the ground is always preferred.

When to plant sunflower seeds

You should sow sunflower seeds in April or May, which is usually when the soil is the ideal temperate and they have plenty of time to grow and bloom during the summer months.

How to plant sunflowers

Sow sunflowers seeds around an inch into the ground or peat-free, multi-purpose compost. If planting into the ground, provide the necessary nutrients by sprinkling the ground with compost, too. If sowing multiple seeds, ensure they’re at least three inches apart, and don’t plant more than one seed in a pot smaller than five inches.

Once sown, water the compost and ensure it’s in a cool but sunny spot if indoors.

It should take your seeds 10-14 days to germinate. Once they have, ensure they receive plenty of water and sunlight. Once they grow past a few inches they may begin to droop, which you can rectify by staking with a cane or something similar. 

How to propagate sunflowers

Once they’ve flowered, sunflower heads produce as many as 1,000 seeds. These seeds can be used in cooking, feeding wildlife, or growing more beautiful sunflowers.

The best time to harvest the seeds is when the petals begin to dry out and fall. To do this, remove the head from the stem and rub the seeds so they fall. Allow the seeds to dry for several days before storing them ready for planting the following year, or remove the seed coat before cooking or eating.

Growing tips

Growing sunflowers may be among the most low-maintenance gardening activities you can do, but here are some extra tips for maximizing your chances of growing some blossoming beauties.

Lighting

Sunflowers need as much soon as possible. Without six to eight hours of sun per day, your sunflowers may struggle to grow and bloom. It’s also important to shelter your sunflowers from heavy wind, as this can cause damage.

If growing your sunflowers indoors, try to keep them in a spot close to a window that gets plenty of sunlight throughout the entire day.

Soil

Because sunflowers grow so big they’re very hungry flowers, so need nutrient-rich soil. Loamy soil (soil balanced with silt, clay, and sand) works best, mixed with peat-free, multi-purpose compost. Not all garden soil is ideal for sunflowers, but adding compost to the soil allows them to thrive in almost any garden.

Watering

It’s important to find a balance between underwatering and overwatering. Sunflowers are thirsty flowers and suffer if they get too dry. The taller a sunflower gets the more water it will need. Try to make sure the soil is never dry, but ensure you don’t go too far or it may get waterlogged. 

Flower food and fertilizer

We’ve already covered how sunflowers love compost, but they’re also partial to kelp or fish fertilizer. There is such a thing as over-fertilization, so whatever fertilizer you use make sure to follow the instructions. 

Common pests and diseases

Sunflowers face various threats from pests and diseases throughout their life, so it’s important to stay vigilant to the dangers.

Pests

After sowing, birds, mice, chipmunks, and other rodents can dig up and eat the seeds. To protect the seeds and seedlings, cover them with a cloche or soda bottle if they’re in the ground. If in a pot, raise it off the ground slightly to make it more difficult for pests to get their paws on them. However, deer do enjoy eating sunflowers, which may be a problem for those living in the countryside.

Once your sunflowers have flowered and produced seeds, they’ll attract birds and squirrels looking for a meal. It can be difficult defending your sunflowers once they’ve bloomed because while covering them can protect them, it also means you can’t see them (and neither can the sun).

You may also find insects and other bugs feasting on your sunflowers, such as slugs, aphids, moths, and caterpillars. One effective way of protecting your sunflowers from creepy crawlies is by spraying them lightly with sunflower oil.

Diseases

Sunflowers attract fungal diseases, such as white mold, mildews, and rusts. It can be difficult to prevent this, but if a sunflower does develop a disease it may be best to remove it to prevent the risk of it spreading to others.

Don’t fancy growing sunflowers yourself? Order a beautiful vase arrangement or bouquet from French Florist for same-day local delivery

Now you know how to grow sunflowers, why not give it a go yourself? If you don’t have the time, know-how, or space to grow your own, the local artists at French Florist can put together a beautiful arrangement of sunflowers, which are available for same-day delivery. Why not brighten up your home, browse our range of sunflowers for delivery nationwide today.