Sunflowers are wonderful and happy flowers that you can enjoy in your garden. Easy to grow at any age, and an enjoyable activity for the whole family, make sure you know the answers to Google’s questions about sunflowers.
Are Sunflowers annuals, biennials, or perennials?
Sunflowers are available as a couple of these options. You can get short-lived annual varieties, and as long-lived perennials also.
When you buy your sunflowers seeds or plants, make sure to check the packet or label for which type you are getting.
You will also find that perennial sunflowers tend to be much smaller than the classic sunflower, and the flower heads will be smaller too.
Which garden style are Sunflowers best for?
I generally would put sunflowers in any garden, they’re so versatile. Often you will find them planted in cottage borders, prairie planting, vegetable plots, and wildlife-friendly havens. The bees love them!
Bedding displays are also great, but if you have limited space, there are some dwarf sunflower varieties that will do well in containers. These varieties grow between 12 inches and 3 feet tall. Just ensure to place your containers in a sunny spot, as they need 6-8 hours of sunlight daily.
Are they easy to grow?
Yes, Sunflowers are easy to grow. They’re a great way to encourage children to start growing plants in the garden.
Your only real challenge will be trying to stop the cheeky birds from taking all the seeds!
It takes roughly 8 weeks for a sunflower to grow from seed. So, to the keep the kids engaged, create a chart to keep track of the difference changes in height and appearance. If you can get hold of a wooden ruler, the kids can measure their height every day! This will keep them excited, and help them to develop patience.
Where do they grow best?
Sunflowers love a sheltered, sunny spot, with well-draining soil. They don’t like their roots to stay wet for too long.
As I’ve already mentioned, they need 6-8 hours of sunlight daily, to make sure they grow their best.
How do you grow Sunflowers?
Make sure to sow your seeds between April and May in individual, 10cm pots filled with peat-free compost.
Ensure that you push your seed 1.5cm deep into the soil, and water it in. Cover the pots with a clear, plastic bag, and place them somewhere cool and bright.
Within 1-2 weeks, the seeds should be clearly germinating.
Keep your seedlings well-watered until you’re ready to plant them out into the garden.
When you plant them out, don’t plant them any deeper than the pot they were in as seedlings. Water them in well.
It’s a good idea to stake next to your sunflowers, as they can grow quite tall. This will give your sunflower extra support as it grows.
How long do they flower for?
You can expect your sunflower to bloom from 3 weeks to a month, if you’re very lucky.
To get the most out of your sunflowers, water them regularly.
Are Sunflowers good for bees?
Are Sunflowers frost hardy?
This depends completely on the variety you’re growing. Some UK varieties are hardy up to -10 degrees Celsius, but you need to check your seed packet or plant label to know for sure. The label or packet will have a hardiness rating, which will tell you how well they will survive cold temperatures.
What colours do they come in?
The most familiar sunflower shade is yellow, but you can also get your hands on orange, ruby, bronze, and bi-coloured varieties.
When do they flower?
You’re most likely to see your sunflowers blooming during the UK summer months.
Depending on the variety, you can enjoy their flowers from between 11 and 18 weeks after sowing the seeds.
Do Sunflowers flower the first year?
Annual sunflowers will flower in the first year after being sown.
Perennial sunflowers grown from seed require a little more patience. They will take at least 2 years to flower.
Do they need a lot of water?
Annual sunflowers thrive well when they are watered regularly, and make sure they don’t dry out. Sunflowers can often find it difficult to recover if they are allowed to dry out for too long. These tall annuals need to stay moist to keep their stems upright.
Perennial sunflowers require regular watering the first year after planting. However, after this they should only need regular watering during or after periods of dry weather and drought.
Do Sunflowers need staking?
Sunflowers can really benefit from a little bit of support, especially thanks to their large, heavy flower heads and long stems.
Placing a long, bamboo cane or stake in the ground next to your sunflower during planting time means they have support throughout the growing season.
You can check the plant’s ultimate height on their seed packet or label, so you have a good idea of how tall a stake you will need.
This isn’t particularly necessary, as if you leave the flower heads where they are, they produce seeds. These seeds are loved by the birds that visit your garden. That is why I grow them, to not only brighten up the garden but to feed these lovely feathered friends. Finches, nuthatches, carnels and woodpeckers all enjoy them from my sunflowers.
Do Sunflowers need feeding?
Big and healthy growing plants always benefit from a nutritional boost, so feed your sunflowers weekly. This encourages more growth, and as a result leads to longer lasting flowers.
Make sure to top up your sunflowers with tomato feed, which boosts flower and seed production, and keeps the plant strong.
Do they change colour?
Different varieties come in different colours. But the only colour change you should notice is when the colours fade as the flower heads come to the end of their life.
What should you plant with Sunflowers?
There are a lot of options to choose from, sunflowers grow well with a variety of plants. Nasturniums in a lovely golden yellow really complement my sunflowers, and if you plant them close by they may even climb up your sunflower stems. This creates a really lovely effect. They also draw in more pollinators.
Marigolds are another wonderful option, as they have a beautiful fragrance, and also deter beetles, leaf hoppers and some types of worm that may affect your sunflower growth.
Cucumbers share the same soil requirements, and their vines can grow up the sturdy sunflower stems well too.
Do they bloom all summer?
You can have continuous flower displays from your sunflowers by sowing new seeds every couple of weeks. This will make sure you have successional growth of new plants between June and September.
If you grow perennials sunflowers, you can enjoy their blooms slightly later, through to October.
When should I harvest my Sunflower seeds?
To get the best seed harvest out of your sunflowers, leave the flower heads on the stems through early autumn for a few weeks. Once the petals have faded, you can remove the flower heads and store them in a sunny, warm, or dry place for an additional week. Great places for this include a spot in your greenhouse if you have one, or your kitchen windowsill.
Once this time is up, place your sunflower heads on some newspaper, and rub the seeds on your flower head gently. The seeds should fall away easily onto your newspaper.
They make a great snack for birds, so if you like you could leave the flower heads outside for them to help themselves.
When do Sunflowers start to grow back?
You can expect your perennial sunflowers to start to grow back as spring comes around. The longer days and warmer soil encourages this.
Perennial sunflowers form sizeable clumps as they are vigorous growers. Try to dig these up and divide them every 3-4 years depending on how big they are. This will make sure they keep growing well, and steadily.
Do Sunflowers self-seed?
Yes, they can be great self-sowers. Once the seed heads mature, the seeds will eventually fall down onto the ground and sow themselves. Birds that eat them will disperse some of the seeds also, by either dropping them or knocking them off the flower head.
What are the common problems with Sunflowers, and how do I fix them?
Slugs and snails
- Young sunflower crops can be susceptible to slugs and snails.
- Make sure your sunflower plants have enough time to toughen up.
- This will make them harder for the slugs and snails to snack on.
- You can also plant them alongside slug resistant plants, like lavender, woody hydrangeas, and agapanthus.
Downy Mildew
- Damp and wet weather can cause this to affect your sunflowers.
- The spores attach to the leaves, and can be quite tricky to recognise, so look out for discoloured blotches.
- Severely affected leaves will have shrivelled up and gone brown, so just remove those.
- Destroy any affected leaves if you can, to avoid it spreading.
Are Sunflowers edible?
Mature sunflower seeds are edible for us.
You will know when they’ve matured as the flower petals will fade, go brown, and begin to fall off.
As long as no pesticides have been used, you can eat the seeds straight from the plant.
If you want some extra flavour, you can cook the seeds in a large saucepan in boiled salted water, simmering for 15-20 minutes. Then pope them in a single layer in the oven on a baking tray and roast for 15 minutes at 200 degrees Celsius.
They have some great health benefits, such as lowering blood pressure!
These bright and happy flowers are easy to grow, and effortlessly cheer up a space. If you have any questions about this or any other plant you want me to do a video on, please subscribe to my YouTube channel and leave a comment below one of my Google Questions videos.
David Domoney is a Chartered Horticulturalist, Broadcaster, and Author. David has worked with a number of the UK’s leading garden retailers as a plant buyer and strategic consultant. With more than 30 years experience, in horticulture, David is as passionate about plants now as he was when he bought his first plant at a village fete.
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