Growing Sunflowers

How to Plant, Grow, and Care for Sunflowers

Pixabay

With bright blooms that go from mid-summer to early fall, sunflowers say “summer” like no other plant. Our Sunflower Growing Guide covers everything from planting to cutting flowers to harvesting seeds!

Sunflowers (Helianthus annuus) is an annual plant with a large daisy-like flower face. Its scientific name comes from the Greek words helios (“sun”) and anthos (“flower”). The flowers come in many colors (yellow, red, orange, maroon, brown) but they are commonly bright yellow with brown centers that ripen into heavy heads filled with seeds.

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

How Long Do Sunflowers Take to Bloom?

A fairly fast-growing flower, most sunflower varieties mature in only 85 to 95 days. The largest sunflower varieties grow to over 16 feet in height, while smaller varieties have been developed for small spaces and containers and rarely grow larger than a foot tall! The flower heads can can reach over 12 inches in diameter within the large seeded varieties.

Sunflowers are heliotropic, which means that they turn their flowers to follow the movement of the Sun across the sky east to west, and then returns at night to face the east, ready again for the morning sun. Heliotropism happens during the earlier stages before the flower grows heavy with seeds.

Very few plants are as heat-tolerant, resistant to pests, and simply beautiful. Sunflowers make excellent cut flowers and many are attractive to bees and birds.

At the end of the season, it’s easy to harvest sunflower seeds for a tasty snack or for replanting (see instructions below). Learn more about why you should start growing these happy flowers in your garden.

Planting

When to Plant Sunflowers

It’s best to sow sunflower seeds directly into the garden (or outdoor containers) after the danger of spring frost has passed anytime after soils have warmed to 50°F.
In most regions, this will fall between April and mid-July. In the south, this will probably occur in mid-March or early April.

Choosing & Preparing a Planting Site

Find a sunny spot! Sunflowers grow best in locations with direct sunlight (6 to 8 hours per day); they require long, hot summers to flower well.
Choose a location with well-draining soil. It shouldn’t pool water after it rains.
Sunflowers aren’t picky but the soil can’t be too compact. They have long tap roots that need to stretch out; in preparing a bed, dig down 2 feet in depth and about 3 feet across.
They’re not too fussy when it comes to soil pH either. 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, plant sunflowers in a spot that is sheltered from strong winds, perhaps along a fence or near a building. Larger varieties may become top-heavy and a strong wind can be devastating.
Before planting, decide whether or not you want to grow a fun sunflower tower.

Sunflowers

Planting Sunflower Seeds

Sunflowers should be planted 1 to 1-½ inches deep and about 6 inches apart after the soil has thoroughly warmed. If you wish, you can plant multiple seeds and thin them to the strongest contenders when the plants are six inches tall.
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.)
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.

Check out this video to learn how to plant sunflowers:

Care

Caring for Sunflowers

While the plant is small, water around the root zone, about 3 to 4 inches 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.

Red sunflower. Photo by Chris Burnett

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. Curious deer may bite the heads off of young sunflowers.
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

Cutting Sunflowers for Bouquets

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

At the end of the season, harvest sunflower seeds for a tasty snack and or to replant or to feed the birds in the winter! Read all about harvesting sunflowers here.

Let the flower dry on or off the stem until the back of the head turns brown, the foliage turns yellow, the petals die down, and the seeds look plump and somewhat loose.
With sharp scissors or pruners, cut the head off the plant (about 6 inches below the flower head). Place in a container to catch loose seeds.
Lie the sunflower head on a flat, clean surface and grab a bowl to hold the seeds.
To remove the seeds, simply rub your hand over the seeded area and pull them off the plant or you can use a fork. Another 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.
If you are going to harvest the seeds for roasting, you can cover the flowers with a light fabric (such as cheesecloth) and a rubber band to protect the heads from the birds.
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.
Rinse sunflower seeds before laying out to dry for several hours or overnight.
If you’re saving seeds to replant, store them in an airtight container in a cool, dry place until you are ready to plant.

Learn how to roast seeds in the cooking notes below.

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, sometimes growing to more than 12 feet tall. Its seeds are excellent for snacks and bird feeders, too.
‘Autumn Beauty’: One of the most spectacular cultivars, the ‘Autumn Beauty’ has many 6-inch flowers in shades of yellow, bronze, and mahogany on branching stems up to 7 feet tall.
‘Sunrich Gold’: A great flower for bouquets and arrangements, this sunflower grows to be about 5 feet tall and produces a single 4- to 6-inch flower. The big, no-mess, pollenless flowers have rich, golden-yellow rays and green-yellow centers.
‘Teddy Bear’: Just 2 to 3 feet tall, this small sunflower 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, beans, and squash.
Some cultures see sunflowers as a symbol of courage.
Sunflowers were not only used for cooking by Native Americans, but also for healing (the oil was used to cure skin ailments) and making clothing (yellow dye was made from the flower petals and black or blue dye from the seeds).
Need a bird feeder? Save whole, dry sunflower heads and set them out in winter. Birds will gladly pick at the delicious seeds!
Save thick sunflower stems and dry them for winter kindling.
An anonymous buyer paid over $39 million in 1987 for Vincent van Gogh’s Sunflowers.
The tallest sunflower ever recorded was grown in Germany in 2014. It measured in at a stunning 30 feet and 1 inch tall!
Kansas is “The Sunflower State.”

Cooking Notes

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.

How to Roast Sunflower Seeds

Re-soak seeds overnight in salted water. Run through a strainer and dry on a layer of paper towels.

Bake for 25 to 30 minutes at 325 degrees on a baking sheet. Seeds should be spread out in a single layer. Stir frequently during the baking and remove seeds when they look slightly browned. Don’t burn!

That’s it! You can all some olive oil, salt, spices to your roasted seeds if you wish.

Or, you can also make suet cakes for the winter birds! See how to make suet.

What do you want to read next?

Marigolds

Salvia

Zinnias

Peonies

Shasta Daisies

Daffodils

Columbine

Chrysanthemums

Hydrangeas

Bee Balm

Roses

Impatiens

Reader Comments

Sunflower seedlings

I have never grown anything from seedlings . I bought your sunflower seeds and little pods. I now have 18 little sprouts and they are wonderful. Now I do not know what to do with them. The weather is cold, rain and even some snow. Please teach me. Thank you :) Heidi

protect your sunflowers

Good to hear of your success. If you are at risk of cold and snow, you must be a northern area that has not passed it last-frost day. (Put your zip code in the slot on this page and see when your last-frost date is: http://www.almanac.com/gardening/frostdates/zipcode/03444)

At this point, it’s important that you protect your seedlings from the cold and snow. One way is to prop newspaper on top of them—not touching them, but above them and supported in such a way that the newspaper, if wet (or worse, snow laden), will not crush the seedlings. Replace as necessary and, when the cold spell passes and the temps are more suitable, remove the paper and let the seedlings get stronger. Watch the weather forecast here regularly —http://www.almanac.com/weather/forecast/zipcode/03444 —and be prepared to protect the seedlings at any time until your area is safely past the threat of frost, snow, or cold.

Take care of your plants and they will be good to you!

sunflower cultivation

Please provide me details of sunflower planting, cultivation, ideal time of planting, good seed from where to procure etc.

sunflowers

And amazing and exceptionally wonderful article on growing sunflowers.
Information was so thorough and helpful.
Thank you

sunflowers

I planted 30 sunflowers and now they are 3 inches tall! I am 12 yrs old and i love to garden. I sell all the plants that i grow, and i make like 40$ off of like 2 plants!!

suitable soil for sunflower

In which type of soil does sunflower give maximum yield...?? Does it grows in red soil..??

growing sunflowers

i love to grow sunflowers in my backyard.

I grew some sun flowers this

I grew some sun flowers this year and harvested the seeds because I am wanting to replant them next year. I am wondering how should I store them? And I am also wondering about the wild sunflowers you see next to the road, is there a way to harvest those seeds and replant them?

Like any seeds, keep them in

Like any seeds, keep them in a cool dry place until you repalnt them in the spring. Make sure it is also rodent-proof because mice love to eat these seeds. Not sure what you mean by wild sunflowers but everything is owned by someone so be sure to have the permission from the landowner before you harvest any seeds from "wild" plants. Watch the plants until they start to dry and then harvest the seeds or cut a few stalks to dry at home.

I PLANTED TWO ROWS OF MAMMOTH

I PLANTED TWO ROWS OF MAMMOTH SUNFLOWERS THAT GREW GREAT. A FEW OF THESE TO ABOUT 10-12', HOWEVER NONE OF THE PLANTS FLOWERED? ANY IDEAS?

When did you plant your

When did you plant your seeds? I also planted a few mammoth the end of May and the first one just recently bloomed. Hopefully my others bloom soon. I believe they have a 75 day maturity. I hope this helps you a little.

Well, you've got the growth,

Well, you've got the growth, so they must be reasonably happy where they are. We think that they got/are getting too little phosphorus. Did you test you soil? Did you fertilize, especially without having tested the soil? A test may have revealed a nutrient balance that fertilizer could have fixed, in the proper mixture.
Basic plant fertilizer mix usually consists of nitrogen (N, and the first "number" in the row of three numbers), phosphorus (P), and potassium (k).
Nitrogen helps plants grow quickly and have abundant foliage.
Phosphorus helps roots to be healthy and helps blooms to set.
Potassium aids in overall plant health.
It's probably too late in season to fertilize now. Get your soil tested early next season, before you plant. Often, local cooperative extension services do this, but you can also buy kits at garder and nursery stores.

I am from Ohio and also

I am from Ohio and also planted the mammoth sunflowers around May 27th, for the 1st time ever. Around 75 plants. We were getting worried that they weren't going to bloom. But recently they started blooming. And they didn't all bloom at the same time, it was like a week between some of them. I have various size blooms on almost all now. I wish you luck and hope they bloom soon for you.

Thanks, wind storm came thru

Thanks, wind storm came thru on the 24th and wiped out most of the plants as I didn't stake them. We will see what happens to the rest but I'm guessing phosphorus as mentioned below. I'll try again next year since the plants grew to such amazing heights.

I live at the mouth of the

I live at the mouth of the keys. It is August and it is hot. Bee friendly sent me some wild flower seeds. Two grew. One I have no clue what it is. It is tall and bushy. The other grey like crazy straight up. At 2 feet of course I staked it. I stake everything that I do not want to flop over. Now I noticed as the flowers (3) are showing their color. I live in an apartment and grow these flowers because the bee population is dying off. I have 2 pkg to plant. Is there a "time"? All we have is sun and humidity. Will they attract bees?

I live in Southern

I live in Southern California. My sunflowers are in full bloom but will die in a month due to the heat and the end of summer. I was curious as to what are some flowers that I can plant that are seasonal and will bloom in the winter to replace the sunflowers? If you know any, it would be extremely helpful, thank you!

I had a great sunflower crop

I had a great sunflower crop this season, but when cutting them down I noticed that there were larvae living inside the stems. They were completely hollow all the way up 6-10 inches beneath the blossoms... what is this and how can I avoid it in the future?

Sounds like sunflower

Sounds like sunflower maggots! A small fly lays its eggs on the stem which then hatch and burrow inside to eat the pith in the center of the stem. Since the pith doesn't have anything to do with the movement of nutrients within the plant, the maggots don't really do any harm. That is why you had a great crop of flowers despite the larvae.

What is the botanical name of

What is the botanical name of sunflower

I planted "vanilla"

I planted "vanilla" sunflowers in my garden for the first time this year. It is now mid-August and the flowers have not bloomed yet, although there is a tiny bit of yellow just peeking out of the center buds. Is this normal? Or did I plant them too late? (I think it was very early June when I planted them). Thanks.

Hi, Karen, If this is

Hi, Karen,
If this is Sunflower 'Vanilla Ice' (the only one we can find with "vanilla" in its name, the sow-to-bloom time is 60 days during a hot summer, according to one source. The same one suggests planting out doors in mid-April through mid-May were cited, with an eye to avoiding a frost (that's directly in the soil; not starting indoors as early as Feb or March) .
Apparently it is a late summer bloomer that can keep going into October, so give it a little more time—and start it earlier next year.

sunflower pests

I always seem to have a problem with small worms that completely destroy the mammoth seeds as they mature. Any ideas on how to prevent this from happening?

When you cut a flower off of

When you cut a flower off of a plant, does a new flower grow from the same stem?

Deadheading sunflower blooms

Deadheading sunflower blooms helps the plant focus its energy toward new flower growth, not necessarily on that particular stem.

one of my plants has 10

one of my plants has 10 heads?????

is that common??

Some types of sunflowers

Some types of sunflowers bloom with multiple flower heads on each stem.

I also have a plant that has

I also have a plant that has grown more like a bush and it has at least 30 sunflower heads maybe more!! I am in awe, as I don't plant any of mine, they all come from birdseed that is dropped. I will call my plant Amazing!!!

Just planted 8 little

Just planted 8 little sunflowers I bought in a shop; all seem to be doing well - even with the lack of sun this summer. My question is will the same sunflowers grow again next year, or is it a case of saving the seeds and growing from them?

Sunflowers are annual plants

Sunflowers are annual plants so you will have to replant them every year.

I was gifted some sunflower

I was gifted some sunflower seeds from a friends plant. The original plant was well over 10 ft. tall. While lovely, her off springs plant, is only about 5 ft tall.
Do they loose height with each next generations planting?

Growing Sunflowers

Botanical Name	Helianthus annuus
Plant Type	Flower
Sun Exposure	Full Sun
Soil Type	Loamy, Sandy
Soil pH	Neutral to Slightly Alkaline, Slightly Acidic to Neutral
Bloom Time	Summer
Flower Color	Multicolor, Orange, Red, Yellow
Hardiness Zones	2, 3, 4, 5, 6, 7, 8, 9, 10, 11
Special Features	Attracts Birds, Attracts Butterflies

How to Plant, Grow, and Care for Sunflowers

Share:

How Long Do Sunflowers Take to Bloom?

Planting

When to Plant Sunflowers

Choosing & Preparing a Planting Site

Planting Sunflower Seeds

Care

Caring for Sunflowers

Pests/Diseases

Harvest/Storage

Cutting Sunflowers for Bouquets

Harvesting Sunflower Seeds

Recommended Varieties

Wit & Wisdom

Cooking Notes

How to Roast Sunflower Seeds

What do you want to read next?

Marigolds

Salvia

Zinnias

Peonies

Shasta Daisies

Daffodils

Columbine

Chrysanthemums

Hydrangeas

Bee Balm

Roses

Impatiens

Reader Comments

Leave a Comment

Pages

Growing Sunflowers

FREE BEGINNER'S GARDEN GUIDE!

The Almanac Webcam

Visit the Almanac HQ Webcam

Chosen for You from The Old Farmer's Store