Sunflower Plant Guide: Grow Sunflowers Backyard, Sunflower Types, Zones, Tips

Sunflower Facts

The Sunflower plant genus is Helianthus. In Greek, “Helios” means sun, and “anthos” means flower.

It is in the plant family of Asteraceae with around 150 species of perennial and annual flowering Sunflower plants.¹

A Sunflower plant derives its name, ‘sunflower,’ from the image and size of the plant,¹¹ which resembles the sun and the rotation around it. It has a daisy-like flower face with petals radiating from its brown centers that eventually mature into a head full of seeds.

These plants have one or more (capitulum) flower heads that are circular and inflorescence. They bear achenes, which develop into seeds.

Sunflower plants are native to the temperate climates of North America. The Sunflower flora offers ornamental and aesthetic products with varying colors.

Whether you want yellow, red, or white, Sunflowers come in multiple shades.

Are Sunflowers Easy To Grow? How Fast Do They Grow?

The growth stages of a Sunflower plant depend strictly on its genetic makeup and background, but know that as long as your seeds are good your plants can grow without a lot of attention.

The planting season also has effects on its development.

A series of reproductive and vegetative stages classifies sunflower development. So, identifying the head or main branch of a single or branched head helps determine these stages.

Growing a Sunflower Plant From a Seed

The easiest and most common way to propagate Sunflower plants is through seeds.

How To Get Sunflower Seeds To Plant

There are two options to obtain sunflower seeds. First, you can purchase them from a garden center.

Alternatively, you may harvest from existing plants. Wait until they turn brown, the foliage yellow, and the seeds are plump or appear somewhat loose.

When heads nod downward, and the petals fall off, cut the sunflower stem and leave about a foot.⁶

After harvesting, you may dry them on or off the stem. When drying the sunflower seeds, keep away from birds.

When dry, place the head on a bucket to let the seeds loosen and fall off, or gently use your hands to slide them from the head. You may use gloves or not, depending on your personal preferences.

Rinse them and place them on a cloth or paper towel to dry. Keep them in a cool and dry place until spring to plant.

Label the seeds with the variety and the date of harvest. They can last for years when stored in this condition in an airtight container.

When To Plant: Best Time To Plant Sunflowers

Plant Sunflower in spring after the danger of frost passes. Depending on your region, start the process either indoors or outdoors.

If doing it indoors, you may begin the process about 3 or 4 weeks earlier. This is a period before the seeds are planted directly into the garden.

Doing indoors can prevent cold snaps from harming the seeds.

Soil for Planting

Sunflower plants are resilient and can grow in any soil type, including sand, silt, and loam. However, they prefer acidic to somewhat alkaline soil.

Therefore, the soil pH should fall between 6.0 and 7.5.⁷

Get local soil testing bags from a nearby agricultural office. Test your soil’s pH level.

If the pH falls below 6.0, add an acid compost or planting mix to enrich it.

If the pH goes beyond 7.5, mix it in granular sulfur. Doing that helps lower the pH level.

How To Plant Sunflowers: A Step-By-Step Guide

The list below shows is a step-by-step guide on planting sunflowers.

1. The first step is to loosen the soil. You can use a hand trowel or your hands.
   When sowing the seeds, the soil should be light, loose, and well-drained.
   Also, it should be rich in nutrients. If not, mix in 3 to 4 inches of compost.
2. Dig an inch deep holes. Space the seeds about 6 to 18 inches apart.
3. Place a few seeds in each hole and cover with soil. Stagger the planting over a few weeks throughout summer to enjoy blooms over a prolonged period.
4. After planting, mix a thin layer of organic fertilizer to promote strong stalks.
5. Water them after planting and fertilizing. Do not flood or drench the seeds.
   Use just enough water to wet the soil.

How Far Apart To Plant

Sunflowers need much space for healthy growth.¹³

Therefore, space apart 6 to 18 inches (45.7 cm), depending on the size of the Sunflower you intend to grow.

(Image: Peggychoucair²⁰)

Allow about 18 inches (45.7 cm) space apart for the larger types. You can allow about 12 inches (30.5 cm) of pace for the medium types between the seeds.

Allow 30 inches (76.2) of soil between each row if planting in rows.

How To Plant Sunflower Seedling

Sunflower seeds take 7 to 10 days to germinate, depending on the soil temperature and moisture.

When seedling leaves sprout, thin them 2 to 3 feet apart. When they hit around 2 inches tall, transplant the Sunflower seedlings into your prepared garden or pots.

If taken to a garden, space them apart depending on the variety. The pots should be around 3 inches in diameter.

If the soil is well drained and nutrients are balanced, carefully remove the seedlings from the tray and place them into the hole or pot.

How Long It Takes To Grow Sunflower Plant

Typically, from the time you place the Sunflower seeds in the soil, it takes about 70 to 95 days to bloom.⁸

However, the blooming period varies among the Sunflower varieties.

When To Plant for the Best Yield: Are Sunflowers Fall Flowers?

During sowing, ensure the soil temperature is at least 6°C. This is usually during spring into summer between March and May and can go up to July, depending on where you live.

You can wait until the temperatures reach between 10°C and 13 °C to achieve better yields.

Growing a Sunflower From a Cutting

You can also propagate Sunflowers through cuttings. Here is the process:

How To Plant Using Stem Cuttings

Propagating Sunflowers from cuttings is more complex than from seed. Different varieties work with other methods.

Here is a step-by-step process:

1. Select a four to six-inch stem with mature leaves without flower buds.
2. Then, use a sharp pruning shear or a knife to make the cuttings.
3. Remove leaves to expose the nodes and remain with only 2 to 3 on top. You may dip the cuttings into a rooting hormone if you so wish.
4. Dip the leafless part of the cuttings into a growing medium, a potting mixture with half peat moss and half sand.
5. Place the pot in a warm area exposed to indirect sunlight, like on a windowsill.
6. Ensure you cover the cuttings fully with a bag to insulate them.
7. Wait for 2 to 4 weeks for the roots to develop. You can test it by gently tugging on the cuttings.
   They are ready if you feel some resistance. At that point, they are prepared to transplant an outdoor space.
8. Expose the cuttings partly to more direct sunlight until they can tolerate full sun.
9. Then, plant them in the garden and remember that the Sunflower spacing ranges from 6 to 18 inches apart, depending on the variety.

Sunflower Care: Best Growing Conditions

Sunflowers are low-maintenance plants. It does not demand much, but it does better in certain conditions.

Here is how to take care of the Sunflower plant:

Watering Needs

A Sunflower plant is drought-resistant. It needs water but not too much.

Only water Sunflower plants only when it is extremely dry.

Sunflower plants have varying water requirements based on the growth stage. During sowing and transplanting, the soil must be moist.¹⁴

The plants require sufficient moisture at the seedling stage, but do not overdo it.

In summer, when the temperatures shoot, water evaporation increases. This means you may have to increase the water supply to prevent the plants from drying up.

During the flowering and blooming stages, the plant demands more water. You should, therefore, increase your water ratio at this time.

Ensure that you water the plants at least 20 days before flowing as it encourages more root growth. This is more helpful for the taller varieties with heavy blooms.⁹

When practicing container gardening, watering your Sunflower plants on time is crucial. Monitor your soil’s condition to know when to water the plants again.

If the leaves lose water and you fail to water it on time, they wither. Also, if the soil is too wet, the leaves at the base of the plant turn yellowish.

Staking To Prevent Flopping or Breaking

Most Sunflower plants that grow beyond 3 feet tall have large, heavy flower heads. These require staking.

If not, they can flop or break when exposed to strong winds and rain.

You can loosely attach their branches to bamboo stakes to help support their weight. Use a cloth or twine them.

Fertilizing

In most soil types, Sunflower plants do not need fertilizers. They only require you to add some if growing them in a very poor soil type.

In this case, use granular fertilizer and allow slow release. That provides enough nutrients, encouraging the growth of larger flowers.

However, be careful not to overdo it. Too much nitrogen can discourage flowering.

Pruning

Annual Sunflowers do not need pruning because they bloom again. However, those growing in groups may need trimming to keep them from knocking each other.

Trimming also keeps them tidy.

Unlike annual Sunflowers, perennials require occasional trimming, twice a year. Trim the tall Sunflowers to half their size in the late spring or early summer.

Cut a third of its size again in June or July. Those in warmer climates should be cut up to two-thirds in June.

Do not prune the plants after blooms appear. This may, however, be different for late-summer blooming varieties.

You should prune them once they reach 1.5 and 2 feet. Usually, they will recover in a few weeks.

Trim the unhealthy, weak, and damaged parts before you do the usual pruning. Ensure you throw them away, not in the compost bin, to prevent spreading diseases to other plants.

Varieties You Can Have in a Sunflower Garden: How Tall Do Sunflowers Grow?

Sunflowers are diverse plants. They can be grouped depending on size, type, and habitat.

(Dwarf Sunflower Image: ulleo²³)(Perennial Sunflower Image: Mohan Nannapaneni ²⁴)(Double Image: Jacques GAIMARD²⁵)(Specialty Sunflower Image: Couleur²⁶)(False Sunflower Image: Rafal Rutkowski²⁷)

The following are the major varieties:³

Giant Sunflowers

The Giant Sunflower plant is around 9 feet tall, but it can sometimes go up to 16 feet tall.

With this height, Giant Sunflowers need staking. This prevents them from falling due to strong winds or rain.

Giant Sunflowers are also wide and heavy. The flower can measure more than a foot across, which is one factor that necessitates the staking.

When it comes to pollination, a Giant Sunflower plant attracts various pollinators. Also, most varieties have edible seeds.

• Height: 9-16ft
• Bloom Size: 10-14+ inches wide

Dwarf Sunflower Plants

The dwarf varieties are short and, hence, ideal for container gardening. A single plant can branch and provide multiple blooms.

Some are bicolored, some are pollenless, and others are double-flowered. Dwarf Sunflowers are ideal for cutting to use in arrangements.

• Height: Ranges between 1-4ft
• Bloom Size: 2-10 inches wide

Perennial Sunflower Plants

Perennials are those flowers that live more than two years. These tough plants offer 8 to 12 weeks of blooms.

They are different because they form clumps with smaller flowers than annual Sunflowers. Most annual types die after a single growing season and need you to replant them the following spring.

• Height: 1-10ft tall
• Bloom Size: 2-5 inches wide
• Zones: 4 to 9

Double

Double Sunflowers attract significant attention for their beauty. Ideally, they are known for their fluffy and soft texture, which gives them an imposing look.

These flowers occur either in a fully-double form or a semi-double one. They are also known to have a longer lifespan than their single-bloom counterparts.

When it comes to pollination, Double Sunflower plants have minimal or no pollen. This and their long life make them excellent cut flowers for arrangements.

• Height: 2-6ft tall
• Bloom Size: 4-8 inches wide

Specialty Sunflower Plants

When many people hear of a Sunflower plant, a bright yellow color comes to mind. However, Sunflower plants can come in a variety of colors.

There are some types of white flowers. Some are bright yellow, while others are deep red.

Still, others have a combination of color shades, giving them impeccable beauty.

• Height: 4-7ft
• Bloom Size: 4-8 inches wide

False Sunflower Plants

False Sunflower, or Ox-Eye Daisy, is a cheerful native perennial Sunflower that grows relatively fast and is easy to care for.

In some areas, the plant is called Oxeye Sunflower or Smooth Oxeye.

It produces dense yellow blooms with an even darker yellow or near-orange center. The flower has a long lifespan, and the quality and color do not wither quickly.

• Height: 3-4ft
• Flower Size: 2-3 inches

4 of the Most Common Types: Along With the Pictures of Sunflowers

Some common types are listed below:⁴

Its big, bright yellow petals form a beautiful circle around a dark chocolate center. This gives it an impressive look that gardeners love.

The Russian Mammoth is also known to attract all types of bees, birds, and butterflies. Its seeds can also be a good snack for you.

Sunrich Gold Sunflowers mature within 60-70 days. They grow into a single stem with a round flower at the top, packed with numerous petals.

However, these flowers do not produce any pollen.

Being pollenless means they are clean, especially when cut and brought indoors. Also, since they are long-lasting, they are an excellent choice for cut flowers.

The Autumn Beauty captures a gardener’s attention as it is a multicolor Sunflower. It has diverse colors, including yellow, red, and orange,⁵ resembling the autumn falling leaves.

Usually, the flower grows to heights of 5-7 feet, with wide blooms reaching 4-6 inches. These nectar-rich blooms attract all kinds of pollinators, from birds and bees to butterflies and other insects.

When it comes to planting, the seeds work well. Plant the seeds in your well-prepared soil or ground, water them, and you are good to go.

The seeds should be at least 1 inch deep and between 6 and 12 inches apart for optimal growth.

The Teddy Bear plant produces average-sized blossoms, which expand up to 6 inches wide. They are soft and fluffy, with a bright gold color that makes them visually appealing.

This also makes them excellent cut flowers any time.

North America Growing Zones for Sunflower Plant: Where To Grow

Except for three South American species, Sunflower plants are native to North America. Different varieties are grown in different planting zones.

Sunflower plants grow in USDA hardiness zones between 2 and 11.

When Do Sunflowers Bloom?

Various types of Sunflowers take between 70 and 95 days to mature. The main stages in their life include germination, vegetative, reproductive, blooming, and harvesting.

Most of these plants usually bloom in summer, although the annual varieties wait until fall. The perennial ones bloom between the 8th and 12th week.

Some start blooming as early as July and end as late as October.

(Image: Hans Linde²¹)

Sunflowers blooming takes around 20 days. This gives you enough time to marvel at their beauty.

The blooming period also attracts multiple pollinators, especially bees and butterflies. These are vital in the pollination process to ensure future plants.

If you want to identify ripe seeds, look at the back of the sunflower. If it has started turning yellow, then the seeds are ripe.

The blooming phase is the perfect time to cut the flowers for arrangements. Put the cuttings in a vase or a bouquet to enjoy the stunning beauty.

Sunflower Plant Tips: Key Planting Tips

There are a few aspects of Sunflower plants that you should familiarize yourself with. Let’s uncover some:

How Much Sunlight Does Sunflower Plant Need Each Day?

Research shows that Sunflower plants require total direct sun exposure. They should get between 6 and 8 hours of sun daily to guarantee proper flowering.

The more sunlight they get, the better for the Sunflowers, it helps them grow to their maximum potential.

What Is the Growing Zone?

The USDA hardiness zone for sunflowers is between 2 and 11. Therefore, if you desire to grow Sunflower plants in your region, you must learn more about the variety that will do well in your area.

When Is the Best Planting Season?

Plant Sunflowers in spring. Sunflower germination occurs when the ground temperatures are 70 to 85 °F.

Therefore, the best time to plant them is just before the temperatures reach that level.

What Are the Best Companion Plants?

Various herbs, vegetables, flowers, and other plants can grow well with Sunflower plants. These include Lettuce, Squash, Clover, Basil, Tomatoes, and Pepper.

These plants mutually benefit each other, forming a beneficial relationship.

(Image: Rob D²²)

For example, certain plants like Garlic, Leeks, and other Allium flowers have a strong smell that irritates insects and pests. That keeps them off your Sunflower plants.

Others, like Crimson Clover, are nitrogen fixers. It helps make nitrogen more readily available for the Sunflowers.

They also prevent weed growth. Combining these plants in the garden is ideal for optimum harvest.

Common Challenges for the Sunflower Plant

Sunflowers are prone to pests and diseases. However, they are not affected as much as most plants.

1. Common Pests

Some pests, like the Sunflower moths, weevils, beetles, and caterpillars, invade the Sunflower plants. However, there are ways to control these pests and protect your yields.

• Use this Natural Pest Control for Sunflower Plant

Controlling pests in your flower garden with natural remedies is the first and most economical option. Which options do you have?

There are several homemade pesticides you can try. These include the following:

• Alternative Pest-Control Methods

Sparing your plants with pesticides and insecticides is the easiest solution.¹⁰ However, do not rely too much on them.

Continuous use is not environmentally friendly.

2. How To Stop Sunflower Plant Disease

Like any other plant, a Sunflower plant is not immune to diseases. The only advantage is that it is quite resilient.

Not many of these diseases cause economic concern in terms of Sunflower yields.

Most sunflower diseases are a result of fungi, bacterial, or virus infection. The most prevalent one is the Sclerotinia head rot.¹⁵

Luckily, it is easy to control the disease. Fungicides are a good option to combat the disease, although not fully effective.

Crop rotation is the ultimate solution to stop Sunflower plant disease.

How To Identify Sunflower Plant

It is hard to miss a Sunflower, especially the giant species. However, these flowers vary in size, color, and type.

Some of them are large with broad flowerheads, while others are just a few feet off the ground.

The Sunflower stalk is uniquely tall and thick. You can identify a Sunflower plant by checking the following:²

Sunflower Seeds

Sunflower seeds are enveloped in a white and black striped shell that has a tender texture. The shells, also called the hulls, are made of cellulose.

When they decompose, they are burned as biomass fuel.

There are three Sunflower seeds: high oleic, linoleic (most common), and sunflower oil seeds. Each variety contains unique levels of saturated, monounsaturated, polyunsaturated fats.

The seeds are commonly classified based on their husk pattern in commercial situations.

Sunflower Leaves

A young Sunflower plant has small, oval-shaped leaves. They have pointed ends and are pretty soft with a velvety texture.

When the plant matures, its leaves become triangular, oval, or heart-shaped. The leaves are also rough-edged and contain a dark green color.

Sunflower Flowers

The plant’s flower head consists of numerous tiny blooms. At its center, where seeds are located, it contains what the bees love, tiny blossoms filled with nectar.

The outer part of the flower contains petals, also known as ray florets.

Pollination in Sunflower takes various forms. It can be self-pollination or through agents like insects, birds, and wind.

Sunflower Plant Heliotropism

Sunflowers are known to be heliotropic. Heliotropism refers to the aspect of tilting their heads to face the sun.¹²

This gives them more exposure to direct sunlight.

They usually move to follow the sun. In the morning, the heads are tilted to the East, where the sun rises.

By evening, they are facing the opposite direction to receive sunlight from the setting sun.

However, this movement occurs during the Sunflower’s early growth stages of the flower. At this stage, the flower is still light and can rotate.

Once packed with seeds, it becomes too heavy to move and settles to face East.

The movement is continuous. This means that even on cloudy days, these flowers still move.

It only stops during a prolonged cloudy or rainy season.

There is one more interesting fact about the movement. If the plant has sufficient sunlight for longer periods, at least 16 hours, the movement stops.

Plants in controlled environments, like greenhouses, also do not experience this movement.

That shows that the plant requires a directional moving light source for heliotropism to occur. It discriminates against different light types.

Sunflower Plant Facts: Common Uses and Benefits

The Sunflower plant is one of those plants that has numerous benefits and uses.

The most common uses include:

Food Source

Sunflower is a good source of food, almost the entire plant.¹¹ For example, the flowers are packed with up to 2000 seeds.

These can be eaten raw, roasted, or just dried.

The best thing here is that the seeds are incredibly nutritious. They make excellent snacks and can also create a paste for bread when you crush them.

The young flower buds are also edible. Also, even the seed shells are not thrown away. You can roast them to brew coffee.

Decorative Uses

Sunflowers are a source of beauty. These types of flowers are perfect for homeowners looking for decorative cuttings.

Wedding parties also love Sunflower. They can make a beautiful wedding display.

They stand out because of their large and bright-colored flowers.

Sunflower Oil

As the name goes, Sunflower oil comes from Sunflower plants. It comes from compressing Sunflower seeds, a process that produces yellow oil.

The oil is non-volatile and is largely used for cooking.

Sunflower oil also works well in beauty products. It is used in facial scrubs or massage oils.

Its moderate smell makes it a favorite for many people.

Medicinal Uses

Dried Sunflower petals are used for herbal tea. The herbal tea has been used for decades among the Iranians and Chinese to lower blood pressure, heal wounds, strengthen the stomach, and accelerate childbirth.

Sunflower leaves make tea. The tea has astringent and expectorant properties.

Also, it is used to treat fevers.

Pounded leaves also turns to a poultice which can help with sores and spider and snake bites.

Sunflower seed consumption lowers the risk of developing heart disease and high blood pressure. Also, they contain nutrients that boost energy levels, reduce inflammation, and support the immune system.

Livestock Feed

Sunflower plants act as fodder for animals. The Sunflower heads, and the stalk make animal feeds.

Animals get nutritional value as the Sunflower plant seeds contain proteins and are high in energy.

Frequently Asked Questions About Sunflower Plant