Growing Sunflowers

How to Plant, Grow, and Care for Sunflowers

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Sunflowers say “summer” like no other plant. Heliotropic, they direct their growth in response to sunlight! Native to North America, sunflowers are heat-tolerant, resistant to pests, and beautiful. You can even harvest them for seed.

An annual plant, sunflowers have big, daisy-like flower faces of bright yellow petals (and occasionally red) and brown centers that ripen into heavy heads filled with seeds.

Tall and coarse, the plants have creeping or tuberous roots and large, bristly leaves. Some sunflowers grow to over 16 feet in height, though there are also varieties today that have been developed for small spaces and containers.

Most sunflowers are remarkably tough and easy to grow as long as the soil is not waterlogged. Most are heat- and drought-tolerant. They make excellent cut flowers and many are attractive to bees and birds.

Learn more about why you should start growing these happy flowers in your garden.

Planting

Sunflowers grow best in locations with direct sunlight (6 to 8 hours per day); they prefer long, hot summers to flower well.
Sunflowers have long tap roots that need to stretch out, so the plants prefer well-dug, loose, well-draining soil; in preparing a bed, dig down 2 feet in depth and about 3 feet across to ensure the soil isn’t too compact.
Find a well-drained location, and prepare your soil by digging an area of about 2-3 feet in circumference to a depth of about 2 feet.
Though they’re not too fussy, sunflowers thrive in slightly acidic to somewhat alkaline soil (pH 6.0 to 7.5).
Sunflowers are heavy feeders so the soil needs to be nutrient-rich with organic matter or composted (aged) manure. Or, work in a slow release granular fertilizer 8 inches deep into your soil.
If possible, put seeds in a spot that is sheltered from strong winds, perhaps along a fence or near a building.
Before planting, decide whether or not you want to grow a fun sunflower tower.

Sunflowers

Planting Sunflower Seeds

It’s best to sow sunflower seeds directly into the soil after the danger of spring frost is past. Ideally, the soil temperature has reached 55 to 60 degrees F.
Give plants plenty of room, especially for low-growing varieties that will branch out. Make rows about 30 inches apart. (For very small varieties, plant closer together.)
Plant the large seeds no more than 1 inch deep about 6 inches apart after it has thoroughly warmed, from mid-April to late May. You can plant multiple seeds and thin them to the strongest contenders when the plants are six inches tall.
A light application of fertilizer mixed in at planting time will encourage strong root growth to protect them from blowing over in the wind.
Experiment with plantings staggered over 5 to 6 weeks to keep enjoying continuous blooms.
If you see birds scratching around for the seeds, spread netting over the planted area until seeds germinate. See more ways to keep birds away from your garden.

Care

While the plant is small, water around the root zone, about 3 to 4 in. from the plant. To protect the plant, it may help to put snail or slug bait around the stem.
Once the plant is established, water deeply though infrequently to encourage deep rooting. Unless the weather is exceptionally wet or dry, water once a week with several gallons of water.
Feed plants only sparingly; overfertilization can cause stems to break in the fall. You can add diluted fertilizer into the water, though avoid getting the fertilizer near the plant’s base; it may help to build a moat in a circle around the plant about 18 inches out.
Tall species and cultivars require support. Bamboo stakes are a good choice for any plant that has a strong, single stem and needs support for a short period of time.

Pests/Diseases

Birds and squirrels will show interest in the seeds. If you plan to use the seeds, deter critters with barrier devices. As seed heads mature and flowers droop, you can cover each one with white polyspun garden fleece.
If you have deer, keep them at bay with a tall wire barrier.
Sunflowers are relatively insect-free. A small gray moth sometimes lays its eggs in the blossoms. Pick the worms from the plants.
Downy mildew, rust, and powdery mildew can also affect the plants. If fungal diseases are spotted early, spray with a general garden fungicide.

Harvest/Storage

For indoor bouquets, cut the main stem just before its flower bud has a chance to open to encourage side blooms.
Cut stems early in the morning. Harvesting flowers during middle of the day may lead to flower wilting.
Handle sunflowers gently. The flowers should last at least a week in water at room temperature.
Arrange sunflowers in tall containers that provide good support for their heavy heads, and change the water every day to keep them fresh.

Dried sunflower heads

Harvesting Sunflower Seeds

To harvest seeds, keep an eye out for ripeness. The back of the flower head will turn from green to yellow and the bracts will begin to dry and turn brown; this happens about 30 to 45 days after bloom and seed moisture is about 35%. Generally, when the head turns brown on the back, seeds are ready for harvest.
Cut the head off the plant (about 4 inches below the flower head) and remove the seeds with your fingers or a fork.
To protect the seeds from birds, you can cover the flowers with a light fabric (such as cheesecloth) and a rubber band.
Alternatively, you can cut the flower head early and hang the heads upside down until the seeds are dry; hang indoors or in a place that’s safe from birds and mice.

Recommended Varieties

Everyone is familiar with the huge sunflowers that grow on towering eight-foot-tall stalks. But did you know that some varieties top off at a modest 15 inches?

The towering ‘Mammoth’ variety is the traditional giant sunflower. It is excellent for snacks and bird feeds, too.
‘Autumn Beauty’: One of the most spectacular cultivars, has many 6-inch flowers in shades of yellow, bronze, and mahogany on branching stems up to 7 feet tall.
‘Sunbeam’: A standout bouquet flower, the van Gogh sunflower grows on a 5-foot plant with 5-inch flowers. The big, no-mess, pollenless flowers have rich, golden-yellow rays.
‘Teddy Bear’: Just 2 to 3 feet tall, this small flower is perfect for small gardens and containers. The fluffy, deep-gold, 5-inch blossoms last for days in a vase.

Wit & Wisdom

Some people call sunflowers the “fourth sister,” in reference to the Three Sisters corn, bean, and squash.
Native Americans saw sunflowers as a symbol of courage.
Sunflowers was not only used for cooking by Native Americans but also for healing; the oil was used to cure skin ailments.
Need a bird seeder? Save whole, dry sunflower heads and set them out in winter.
Save thick sunflower stems and dry them for winter kindling.
Interesting Fact: An anonymous buyer paid over $39 million in 1987 for Vincent van Gogh’s Sunflowers.
Kansas is “The Sunflower State.”

Here and yonder, high and low,
Goldenrod and sunflowers glow.
–Robert Kelley Weeks (1840–76)

Cooking Notes

Sunflowers are one of the most important oil crops in the world, and are a valuable food source in many countries. Just one ounce of sunflower seeds contains about 6 grams of protein and 14 grams of oils. The fats are almost entirely unsaturated with 9g of polyunsaturated and 3g of monounsaturated fats per ounce (NSA). The oil is high in linoleic acid and is a good source of vitamin E.

Some varieties produce small black seeds that are used in cooking oil, margarine, cosmetics, and animal feed; they are the best sunflower seeds for attracting the greatest variety of songbirds.
The bigger, striped seeds are grown for snacking and as an ingredient in bread and health foods. They, too, are used for feeding birds, especially larger species, such as jays and mourning doves.
For eating, the seeds must be dried on the plants. Rub the seeds off and soak them overnight in a gallon of water to which a cup of salt has been added, then dry them again in an oven at 250 degrees F for 4 to 5 hours. Store them in an airtight container.
One way to remove them is to rub the head of the sunflower across an old washboard or something similar. Just grip the head and rub it across the board as if you were washing clothes.

Reader Comments

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You need to move the mammoth

You need to move the mammoth sunflower from the pot into the ground. They have the need for roots to expand. If you don't move it, it will not do well. It may even blow over in a wind or die before the plant can flower if left in the pot. Move to the ground. Once you move it because it's already leaning you may need to support it against something (tie it to a fence, etc). They need food so fertilize and don't fertilize directly onto the plant; fertilize about 10-18" out from it in a groove made around the plant. Birds, bees, squirrels love it. In case you see the flower drooping after it blooms and looks so lovely it could be caused by them feeding on it. It's a labor of love but worth the big beautiful flower you get.

I planted the same type of

I planted the same type of seeds this year as last year, but I planted more seeds, and spaced them about 9 inches apart from each other (this was in late May in Beijing). Now the plants are at least 10 feet tall, but the blossoms are small, about 3 inches in diameter (this is the center part where the seeds are). Last year they were at least 7 inches across (where the seeds are). Are the blossoms small because I planted the seeds too close to each other?

My 7 year old planted 2 dwarf

My 7 year old planted 2 dwarf sunflowers from seed and gave them to me for mother's day this year. I replanted them into somewhat bigger pots than what they had come in.
One sunflower bloomed about 10 days ago. It was just magnificent!! We just came back from a 4 day trip up north to find the 1 sunflower that had bloomed so magnificently, dying, drooping, and it's seeds falling out. My neighbor said she had been watering it. We live in Minnesota and it's been in the 90's lately.

What can I do to revive my poor sunflower?

Is your sunflower in a very

Is your sunflower in a very deep pot? Sunflowers need room for their roots so when grown in a pot, it has to be a deep one. And sunflowers are heavy feeders so adding a slow release granular fertilizer to the soil will benefit the plant.

Hi I have 3-4ft sunflowers in

Hi I have 3-4ft sunflowers in pots not quite flowered can I put them in the ground as I have had a change of mind regards rob

Hi, can the same sunflower

Hi, can the same sunflower seeds used for growing be eaten? must it be processed or are they typically the same?

It is not advised to eat the

It is not advised to eat the seeds in the garden seed packets.

Can anything be done with the

Can anything be done with the stalks?Is there anything useful that the stalks can do>?

I planted sunflowers about

I planted sunflowers about two weeks ago, at first they were beauties seemed to be doing fine, then all of a sudden lost their leaves, dying. What did I do? They seem to get enough sun. I water about every other day. Temps in the 80s. Help. Same thing always happens. All my other flowers are beautiful.

Make sure your sunflowers are

Make sure your sunflowers are getting a lot of sun -- like at least 6 hours' worth a day. They also need to be moist, but in well-drained soil. Water them deeply (to encourage root growth), but not too often. And the soil needs to be fertile -- well-rotted compost mixed in works well.

Hello, here in the Republic

Hello, here in the Republic of Panama the sunflowers grows by itsetf under and around my parrot cage. Therefore, I would like to start my own plantation. What is best time of the year to plant the seeds.
I welcome and appreciate any advise.
Best regards

I want to plant sun flowers

I want to plant sun flowers this week June 23 for dove hunting. Do you think the seeds will be ready for doves to eat by September? I live in Peoria Illinois

I am planting my field

I am planting my field tonight. Last year I planted the third week of May, and they started to flower in early to mid August. I don't think the seeds would be ready by Sep 1st, but there should be flowers out by then. It seemed to me last year that the doves were in my field as soon as the sunflowers were tall enough and strong enough to hold the birds, which was a few weeks before the heads opened up anyway. I would say the least you can do is try!

We've been growing many

We've been growing many varieties from seeds past 2 years. This year we have lots that popped up before we planted our started seeds, assuming from fallen seeds last year, will they flower?

Yes, sunflowers will

Yes, sunflowers will self-seed and reproduce to produce flowers.

I planted a sunflower in a

I planted a sunflower in a planter box back in early May (maybe late April). It is about 6 feet tall now, with a healthy and hearty stalk, and it has been green and healthy until last week. Suddenly the leaves are all wilting and turning brown. Is it because I water too much (lightly 3 days a week)? Is it because I have it in a planter box and it isn't getting enough root space (the box is only about a foot deep)? Is it too late to try to save it? Any help would be so appreciated. I've been really enjoying watching my sunflower grow and I'm devastated it seems to be dying.

Hi, I have already planted my

Hi, I have already planted my sunflower seeds for 3 weeks already. It did germinates. But it's been 3 week but just like a inch tall? it only have 1 pair of leaves and that's all. What happened?

Hi, There are numerous

Hi,

There are numerous factors that may have affected the size and health of your plants. Unfortunately it is difficult to evaluate and narrow down precisely what happened.

Based on my experience however, small sunflowers may be associated with overcrowding, nutrerint deficiencies in the soil, unfavorable weather conditions, not enough sunlight, disease, transplant shock, drought/overwatering stress, or insect/ fungal damage either above ground or below.

I would continue to wait and allow the plants more time to grow. If they continue to perform poorly.. Let them grow the entire season until they die to see what happens.

Also, check to see how closely your sunflowers are growing, if they are crammed together tightly, air cannot circulate between the plants and they will also compete and ultimately grow weak and stunted.

Any of the above mentioned factors may be responsible for your small sunflowers.

If you would like to precisely identify the cause of your small plants..you can take soil and plant samples and send them to a lab for evaluation..they will identify what went wrong or what is missing from your soil..you can then correct accordingly and gain experience for the future.

I am confused by the

I am confused by the following instructions:
"Find a well-drained location, and prepare your soil by digging an area of about 2-3 feet in circumference to a depth of about 2 feet."
and
"Give plants plenty of room, especially for low-growing varieties that will branch out. Make rows about 30 inches apart. (For very small varieties, plant closer together.)
Plant the large seeds no more than 1 inch deep about 6 inches apart after it has thoroughly warmed, from mid-April to late May."

Should I plant the seeds in the trench described in the first instruction by following the guidelines in the second instruction?

Hi Liz, Just turn the soil

Hi Liz,
Just turn the soil over in a section of your garden and follow the instructions on how deep and how far apart to plant.

I gathered some sunflower

I gathered some sunflower seeds from a dried seed head that I found on the road near a field of sunflowers in Tuscany last Fall. Not sure what variety it is. Is it too late to plant in Seattle, WA area? I had misplaced the envelope with the seeds in it and just found it today (June 14th). Any idea what variety it might be? Tiny black seeds. It seemed that all of the sunflowers in Tuscany were the same variety. Thanks!

Hi, The seeds you collected

Hi,

The seeds you collected are likely from a "wild" uncultivated strain of Helianthus annuus. Wild H. annuus differs from traditionally cultivated varieties because wild forms typically have numerous branching stems and smaller flowers. Also, they have different germination habits than domesticated forms.

If you would like to plant the seeds you collected.. I would highly suggest that you sow them in the fall or winter because they likely require stratification(meaning to be exposed to cold, snow, and frost) for improved germination. If the seeds are stratified, a naturally occurring chemical called auxin will be broken down, thereby allowing increased germination rates in the spring.

Naturally occurring chemical inhibitors such as auxin are found in most wildflower species. The chemicals are necessary so that germination does not occur until ideal conditions are present in the spring.

Consider this, If the seeds were dispersed and then germinated in the fall after the plant has finished its life cycle..the newly emrged sprouts will be killed by the harsh, cold weather. However, chemicals in the seeds protect this from happening by delaying germination until spring.

Ultimately, to answer your question...if you planted the seeds now, they would probably germinate, but very sparsely and you would get poor rates..likely about 5-20%. Whereas, if you sow the seeds in the fall..they will sprout in the following spring and germination rates will be relatively 50%+..that figure will be higher depending on the quality of the seeds.

Finally..in contrast, why do cultivated, domesticate sunflower varieties not require stratification? This is because domesticated varieties were bred to possess specific desirable traits..and in this case..humans eliminated the need for stratification to make the process of planting sunflowers more effective and streamlined.

Take my advice for planting wild sunflowres. I have gained my knowledge through experience and years of trial and error. I have tried many planting techniques with native, wild sunflowres and now through experience; I know the best methods.

I just want to double check

I just want to double check if it's too late to plant sunflowers at this time of the year. I know you said to plant between mid April to end of May, but what if I start planting them end of June? Or some time during summer?

Plant by June 15 n never

Plant by June 15 n never plant after July second...GoodLuck

I planted sunflowers seeds

I planted sunflowers seeds for the first time in our backyard here in San Diego, CA. Thirty-five of them have come up. They are growing rapidly and beautifully. They all have little heads already. However, they need so much water!! I had no idea. Because of our drought, we are having to water using "gray" water from our rinse water (for dishes), rinse water from bathing, and rinse water from our washing machine. We have no choice about using the gray water, but what I want to know is if we can still eat the seeds having used gray water to grow them? Also, some of the smaller plants do not get enough sun, so I'm thinking of cutting off some of the huge leaves at the bottom of the bigger plants to give the smaller ones more sun. I saw a comment from above that some people have had success with this. Thank you.

Hi Emily, We feel for all

Hi Emily, We feel for all those affected by this devastating drought. We haven't experienced this issue, but here is a helpful fact sheet:
http://www.encinitasca.gov/modules/showdocument.aspx?documentid=1111
"Graywater can be used to irrigate landscaping and plants but not on root crops or edible parts of food crops." At with vegetables, this suggests you'd need to cook the food to ensure no bacteria exists.
To get an accurate answer, we'd need to refer you to the San Diego County Water Authority: www.sdcwa.org/contact-us

This is my first year growing

This is my first year growing sunflowers and something's just not right. They're roughly 2 feet tall now and probably half of them have flopped right over. I can't seem to find anything in regards to this anywhere. Do you have an ideas? The stalks and leaves look fine, they're just not standing. Someone suggested a little boron added to the soil. What do you think?

Lots of sunflower varieties

Lots of sunflower varieties require staking. Give that a try.

I planted sunflowers in early

I planted sunflowers in early May but there is no sign of them yet and it is June 3 could this be because of soil temp I'm in Ireland and it has been cold all through May if I plant some now when should I see growth

It's best to sow sunflower

It's best to sow sunflower seeds directly into the soil after the danger of frost is past. Ideally, when the soil temperature has reached 55 to 60 degrees.