Growing Sunflowers

How to Plant, Grow, and Care for Sunflowers

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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.

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Reader Comments

sunflowers fading

It’s hard to tell what’s going on here exactly, but if you planted hybrid sunflowers last year and this year’s are volunteers, they are not likely to repeat the growth pattern they had last year. Hybrid seeds are “made” to perform once, and never quite the same way again. Heirlooms, on the other hand, will volunteer and regrow to be very similar to the prior year’s plant. So curb your enthusiasm and enjoy the marigolds. Plan to do something different next year. It will be here before you know it!

sunflower

One of my sunflower, the flower was bit off. Will another one grow or should I get another one?

Sunflower leaves

I Just started growing sunflowers and I noticed that the leaves are curling. Is this normal? What can I do or should I do nothing

Thank you
from East Meadow, New York

Keeping critters from devouring sunflower seeds

I am at my wits end from keeping rabbits, chipmunks & squirrels from either digging up & eating sunflower seeds to biting off the seedling heads. I have gotten to the point of having my husband putting a shelf on the outside back wall of our garage & planting sunflower seeds in a pot on a shelf on the wall! Even then - I wonder if chippy can scale the wall vertically! We'll see. I also tried repellants & moth balls - nothing works for long. I managed to have one sunflower seedling that grew up with a squash plant - maybe the rabbits don't see it. It's now June 25th, and I am trying one more time for the season - is this too late? We're in zone 6 - south of Lake Ontario near Syracuse NY

Sunflowers Late June

Go ahead and try again. See if you can find them in 4-inch pots (versus starting from seed).

growing sunflowers

Hi. I wanted to know if it is too late for me to plant sunflowers in metro Atlanta Georgia? Also, where is the best place because my house gets direct sun on the front side in the morning and direct sun on the back side in the evening? if it is too late for outside, can I grow them inside until I can transfer them out? I have a hard time keeping plants alive both indoor and out but the planting of sunflowers was a request from my aunt as a memorial. I want to honor it if possible. Thanks for your help!!!!!

sunflowers in sun

Hi, Karina, It’s never too late to try! As noted above, the plants or seeds should get 6 to 8 hours of sun. plant where the sunlight falls the longest. If it’s really even-steven, you could try both sides! Your area has the benefit summer weather into the fall, so you may have more luck than you think. Bottom line: better to do it and know you tried. Next year, just start sooner!

Hi! I live in Atlanta as well

Hi! I live in Atlanta as well and I planted a sunflower seed and it was absolutely beautiful! It's about 7feet tall and I have the same issue with sun in the front and back but I played the sunflower in the front for the morning sunshine and it worked. I only watered it once a day around 8pm each night! I would be happy to send pictures if you'd like! Good luck!

Hollyhocks

When to plant? I live in southern utah.
Is it a good idea to Soak seeds overnight
before planting any Variety of Plant?

sunflowers

Hi, i planted some sunflowers. The kind with only one bloom. I just wanted to know what kind have more then one bloom. I would to plant those so i could keep seeing the blooms come in.

Sunflower growing

I live in Michigan and want to start growing sunflowers and I was wondering when the best time to plant seeds and how to keep them growing annual?

Michigan is such a great

Michigan is such a great place. The corn grows there! If you already have a garden open, plant your seeds directly in the soil about an inch deep. Make sure its in a sunny location...all day sun. Sunflowers are annuals, meaning they only grow once. Then harvest your seeds after the flower blooms and wilts by cutting the flower off about 6" down the stalk and the rest is in this article.
Good Luck

sunflower growing

I like farming and I would like to start growing sunflower at a large scale (commercial) . Growing like 50 bags of sunflower how many 50 kg bags of fertilizer do I need? Please I need your advice

Hi Stanley,

To grow acres of sunflowers will take some planning. Please go to the links below to get some good advice.

http://www.sunflowernsa.com/growers/

http://sanangelo.tamu.edu/extension/agronomy/agronomy-publications/sunfl...

Fall bloom

I would love to have some mammoth sunflowers
Bloom in the fall, when do I plant here in Califonia?

When To Plant Sunflowers

They take 80-120 days to bloom. I would plant some now and every 2 weeks until about mid July.

Sunflower seeds

I am searching searching... I want to harvest my mammoth sunflower seeds in order to plant more! How long should/would I need to wait after harvest to plant the freshly harvested seeds? And is this standard practice for most sunflower seeds. Thanks so much.

Before you harvest the seeds,

Before you harvest the seeds, the sunflower head must be completely dry. If you leave the heads on the plants to dry you risk loosing some to birds and other critters. Drying them indoors or in a protected area is a good idea. The time it takes to dry depends on how mature the seeds are and what the conditions are in the area where you dry the seeds. Like any seeds, keep them in a cool dry place until you replant them next spring.

mammoth sunflowers / help please

I have never grown sunflowers before and not sure what they are suppose to do mine are about 4 feet tall right now some have one bloom on them and others have 4 or 5 the blooms are only about 3 to 5 inches but the yellow petils are already falling off is that normal I thought the mammoth had large flower heads on them and well the bloom more this season ? Any help would be appreciated .

Dwarf Sunspot Sunflowers

How deep should the soil be for dwarf sunspot sunflowers in containers? Thanks

pot size

Most sunflowers develop pretty significant root systems, even small ones like these that mature at 1 to 2 feet, so give them about 10 inches—that a base (underground) of about one-third to one-half of the plant at maturity. It’s a rough gauge—you just don’t want the plants to be top heavy in pots that are too small.

Hey there

I'm in Southern California and I'm seeing if there is a market for 3-4 week old, single stem, pollen free, grown from seed sunflowers.

Thanks

Craig

Squished stem

My kindergarten's class planted sunflower seed in milk cartons. Today they sent them home from school and my rambunctious 5 year old was expected to get this poor baby plant home safely without any kind of stake or support. (Ya right). So anyways when she got home the stem is kind of squished about halfway up the stem and it no longer wants to stand at all. I used plastic straws to prop it up the best I could but I'm hoping I can still save this poor plant. My daughter and I would both be very sad to lose it. I just have no idea what the best action is. Do I continue to support it for now and wait til I can transplant it or is there some course of action that would be better. Please help.

Popsicle sticks might be a

Popsicle sticks might be a good tool for propping your sunflower. If the sunflower is planted in a small container, you need to plant it in the garden. Wait until the last frost date in your area.

https://www.almanac.com/content/frost-chart-united-states

sunflowers

i started my seeds inside they are king of tall can i plant them deeper than 5 inches as long as the leaves are above the soil????

We normally plant sunflowers

We normally plant sunflowers seeds directly into the ground because sunflowers have long taproots and it’s often hard to predict when the soil is warm enough to plant.

Most seedlings do best when they’re transplanted right away but if they get too leggy, it should be OK to transplant them deeper. Bury them to about 1” below the lowest leaves. To avoid pests, you may want to keep a milk bottle around them until they’re well established and maybe circle them with slug deterrant, too.

care of sunflower

have rescued a 4 ft tall sunflower, thick stem, leaves all almost withered and a big head on it which is totally brown. can you tell me what fertiliser I should put on it if any. I have put it in a fairly deep hole in a sheltered position formed by 2 walls and it will get plenty of afternoon sunlight. how often should I water it. the soil here is sandy. and will its leaves grow back

If the flower is brown the

If the flower is brown the plant is probably not going to bloom again. Most tall sunflowers only grow one flower and after it matures you’ll see the sunflower seeds.

sunflowers

I had to redo a garden and added a lot of soil suitable for roses as well as compost. A selfsewn sunflower came up and reached a height of just over a metre. The flower head was as big as a small dinner plate. I have harvested this for my cockatoo but I am not sure if the plant will produce any more flowers or should I now pull it out. It doesn't have any sign of any more flowers forming and we are now coming into Autumn so it is getting cooler.

Hi Jan,

Most of the tall varieties of sunflowers have one flower per stem. Some bushier varieties have side stems and multiple flowers. It sounds like your plant is single flower. After you harvest the seeds you can pull the stem. You can save a few of the seeds to plant next spring.

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

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