Growing Sunflower plants is one of the really fun parts of summer time gardening. These cheery sun-facing flowers are a delight to gardeners who wish to attract birds.
These big annuals are very easy to grow, which makes them a very popular plant to get children interested in gardening.
Kids will love seeing just how tall these mammoth flowers can grow.
What are sunflower plants?
Sunflowers (Helianthus annuus) are a member of the Aster family.
The sunflower is the state flower of Kansas. It is native to Central North America and has been cultivated for centuries. One only has to drive through the Mid-West part of the USA to see how prolific the flowers are.
The common name “sunflower” refers to the annual variety of the plant. There are also perennial sunflower plants, but they are not often grown, because they spread easily and are quite invasive.
Tips for Growing Sunflower Plants
Sunflower plants do best in bright sunlight with well draining soil. Since they grow easily from seed, they are often seen in gardens and along the road side of state highways.
These tips for growing sunflower plants will help you to have success with this popular annual.
How to grow Sunflower Plants
There are over 70 species of the sunflower plant. They range in size from dwarf sunflowers that are only 1 1/2 feet tall to Mammoth giant sunflowers that can be over 8 feet tall or even more!
Their size makes them a good choice when landscaping to cover a chain link fence.
The heads of the largest sunflowers can be a foot or more in diameter!
Soil Requirements for Sunflowers
Sunflowers are not too fussy about the type of soil, so they can be sown in most areas of the garden and in large pots on deck gardens.
However, they are heavy feeders, so adding compost or other organic matter to the soil at planting time will result in better plants that produce more flowers.
When the new growth starts in spring, add a slow release fertilizer to keep the flowers growing all season long.
How Much Sun do Sunflowers Need?
These plants are called sunflowers for a reason – they love the sun!
Plant them in full sun and try to situate the plants on the northern side of the garden, so that they won’t shade other plants or vegetables when they are grown.
Growing sunflowers in the shade will result in stunted flowers that reach for any available sunlight.
How much water do sunflowers need?
Even though sunflowers are drought resistant, they will grow much better if you give them water regularly, especially after the flowers develop.
In general, as long as you water deeply once a week and make sure that the plants get at least an inch of water a week, the plant will do well. This water can come from either from rain or additional watering.
If it hasn’t rained in a week in your area, it is time to water your sunflower plants again!
Flower Heads
The flowers of the sunflowers are amazing when they open. They can take time to develop but are worth the wait!
In the wild sunflowers will have more than one head on long stalks. Most garden sunflowers of the normal height varieties will also produce multiple heads.
The taller varieties usually have one head per stem, with all the energy spent growing those long stalks.
Sunflower varieties
The flowers themselves vary dramatically. There are many colors and sizes available.
We all know the bright yellow sunflower with a black or brown center but there are so many other varieties, too – from multi colored plants to huge fluffy Teddy Bear Sunflowers that are so popular right now.
They make fabulous cut flowers for bringing indoors.
When do Sunflowers Bloom?
There is nothing quite like the look of a sunflower in your garden! #♥sunflowers #gardenfaces #hello summer Share on XEach variety is different in their bloom time, but generally sunflowers spend spring getting to their maximum heights. Summer time and part of fall are their peak bloom times.
Even though sunflower seeds sprout quickly – in 7 to 10 days – you may need to wait for up to 2-3 months after planting seeds for the flowers to appear.
Do Sunflower Plants Attract Wildlife?
The seeds and nectar of sunflowers are attractive to many forms of wildlife. Bees, wasps, and butterflies are drawn their nectar.
All animals that save seeds for the winter, such as chipmunks and squirrels, love them. Even raccoons and garden mice will enjoy a sunflower treat or two, as well.
It’s a good idea to leave dead seed heads of sunflower plants for when the cold weather comes. This gives additional food for any birds that may be around in the winter months.
When to Plant Sunflowers
Seeds should be sown after the last frost date when the soil is warmer. Sow seed directly if you can.
While you can get a head start by starting seeds indoors a few weeks before the last frost, they really prefer to be sown directly into the soil. Transplanting Sunflowers doesn’t seem to work very well, in my experience.
Plant seeds an inch deep and about 6 – 12 inches apart. Plant 1 1/2 feet apart for the larger varieties. Water well after planting.
Harvesting Sunflower Seeds
Birds love the seeds of sunflowers, which can make collecting them for personal use hard. Some gardeners recommend covering flower heads with cheesecloth, pantyhose, or the perforated bags that vegetables come in if birds become too much of a nuisance.
The time to harvest seeds is when the backs of the flower heads turn yellow and the seeds start to turn brown. The heads will usually start to droop when they are ready for you to harvest the seeds. 
It takes 80 -120 days for seeds to develop flower heads, depending on variety.
Roasted Sunflower seeds make a great snack, similar to pumpkin seeds. To roast sunflower seeds, soak them over night and then bake for 200 º F for 3 hours. Add salt if desired.
When fall rolls around and pumpkins are in big supply, combine them with sunflowers for a unique fall decoration. See the sunflower pumpkin idea here.
Uses for Sunflower Seeds
Growing sunflowers can attract wildlife and also brings beauty to the garden.
Since sunflowers have such thick stems, you can use them as living supports for climbing vegetables.
Their size also makes them perfect for wind breaks and privacy screening.
A Note on Sunflowers and Grass
If birds feed on your sunflowers, it may be hard to grow grass near them. The hulls have a toxin that will kill the grass.
Either harvest the seeds before they start to fall, or plant the sunflowers in a place where the grass does not grow nearby.
My daughter’s favorite flower is a sunflower. We snapped this picture of her one day on the way to college. She just HAD to be in that field!
If you have young children, try to get them interested in gardening by growing sunflowers. The seeds are large and easy for them to handle and they sprout and grow very quickly.
Once they stand at the foot of a fully grown sunflower and see how tall it is, they will be hooked!
Pin these tips for growing sunflower plants for later
Would you like a reminder of these sunflower care tips? Just pin this image to one of your gardening boards on Pinterest.
Admin note: This post for growing sunflower plants first appeared on the blog in April of 2017. I have updated the post with new information, a care tips card and a video for you to enjoy.
Tips for Growing Sunflower Plants
Sunflower plants are a delight in any garden setting. These sun-facing plants are easy to grow and popular with children.
Materials
- Sunflower Seeds
- Sunny Garden Spot
- Compost or other Organic Matter
- Timed release Fertilizer
Instructions
- Add compost to the ground and mix it in well.
- Plant sunflower seeds directly in the soil after danger of frost has passed.
- Space seeds 6-12 inches apart for most varieties or 18 inches for mammoth varieties.
- Be sure the spot gets 6-8 hours of direct sunlight each day.
- Spread timed release fertilizer when the the plants start to grow.
- Be sure the plants get 1 inch of water a week.
- Harvest when the seed heads start to drop, the backs turn yellow and the seeds turn brown.
Notes
Attractive to birds and Butterflies
Recommended Products
As an Amazon Associate and member of other affiliate programs, I earn from qualifying purchases.
Deb
Sunday 30th of August 2020
Hi Carol, I am considering sunflowers in 2 acres on my property that is currently being mowed. Trying to think of something low maintenance & cost effective but beautiful to look at. Sunflowers come to mind. Not sure what the cost would be to accomplish this. What is process after seeds are harvested? Would the ground need to be reworked every spring for new planting? Or would a perennial type of flower work? At a loss on 'how to' turn 2 acres of lawn into 2 acres of sunflowers (or wildflowers?). Can you help?
Carol Speake
Tuesday 1st of September 2020
I have never mass produced sunflowers and your location conditions matter. I would consult a local landscaper in your area.
Liz
Monday 5th of August 2019
Squirrels eat my sunflowers soon after they flower. Whether on the deck in pots or in the ground, the squirrels destroy them. Any tips for keeping them away?
Carol
Monday 5th of August 2019
The only thing that I have found about squirrels is that you can't control them. Hopefully another reader will have some good advice.
Chris
Wednesday 22nd of May 2019
I love growing sunflowers just to fee the birds and such. Some day maybe I'll dry them and eat them. For now I just plant them and let them go.
Mary Pierce
Friday 25th of May 2018
Thank you for all your helpful insight. I planted a "first garden" with my 4 year old grandson this year and sunflowers were, of course, my first choice of seeds to plant with him. The stalks are now around 4 feet tall and he is amazed at how big they are. Can't wait until he sees them at 10 feet with blooms! Next year we're planting a larger vegatable garden (mostly green beans, peppers and tomatoes this year), but sunflowers will remain a fixture in the new garden too.
Carol
Friday 25th of May 2018
My daughter loves sunflowers too! Be sure to take a photo of him later standing near the giants! Carol
Adena
Friday 25th of May 2018
If you start you seeds indoors, how big should they be before transplanting them outside?
Carol
Friday 25th of May 2018
Hi Adena. Sunflower seeds ideally like to be planted directly in the soil where they will grow. They don't transplant well. If you have started seeds indoors there is no real size limit. Just be sure they are well rooted and plant the whole thing, soil and all into the ground. Not ideal but it should work. They won't be as strong as seeds planted directly in soil outdoors. Carol