Sunflowers are a stunning and iconic plant, known for their large, vibrant flowers and impressive height.
Native to North America and belonging to the Asteraceae family, sunflowers are now cultivated all over the world. Chances are, they are abundant in your local neighborhood!
Sunflowers are popular not only for their beauty, but also for their nutritious seeds, which are often consumed as a snack or used in cooking.
This makes them quite a rare flower you can grow in your garden as you can enjoy its natural beauty and its health benefits when consuming its seeds.
If you’re thinking of cultivating these plants, it’s important to understand the growth timeline and life cycle of sunflowers.
Sunflowers have a relatively short life cycle, typically taking around three to four months to mature from seed to full-grown plant.
During this time, sunflowers go through several distinct stages of growth, including germination, seedling development, vegetative growth, and flowering.
In today’s article, we will explore everything you need to know about sunflower growth timeline and life cycle.
We will discuss each stage of growth in detail, including the optimal conditions for growth, common problems that may arise, and how to care for your sunflowers throughout each stage.
Whether you are a seasoned gardener or a novice just starting out, this guide will provide you with all the information you need to successfully grow and care for sunflowers.
Let’s get gardening!
What Is A Sunflower?
Okay, this may sound like a silly question as we all know a sunflower when we see it.
But, have you ever stopped and thought “what actually is a sunflower?” Well, a sunflower is a type of flowering plant that belongs to the family Asteraceae.
They are known for their large, bright yellow petals and dark centers that resemble the sun (hence the name).
They are native to North America and were first domesticated by Indigenous peoples over 1,000 years ago.
Sunflowers are now cultivated all over the world for their beauty, as well as for their nutritious seeds, which are commonly used in cooking and eaten as snack food.
Compared to many flowers, sunflowers can grow to be quite tall, with some varieties reaching heights of up to 12 feet (3.6 meters).
They have large, broad leaves that are arranged in an alternating pattern along the stem.
The flowers themselves can range in size from small to quite large, with some varieties having blooms that are up to 12 inches (30 centimeters) in diameter.
Overall, sunflowers are hardy plants that can thrive in a variety of soil types and climates, making them a popular choice for gardens and agricultural fields alike, and why they grow so well in many regions of the world.
Sunflower Growth Timeline
Sunflowers have a rapid growth cycle. The growth timeline follows this process:
- The sunflower seeds start to grow and become seedlings.
- The seedlings continue to grow and develop into robust plants.
- Once the sunflower has matured, it grows buds that start to bloom.
- Pollinators then visit the flower’s blooms and the seeds develop.
- The seeds then ripen before the sunflower begins wilting.
- Some seeds from the flower start to fall into the ground and the growth cycle starts once again.
Altogether, there are over seventy sunflower varieties worldwide, and not all of these boast that distinctive yellow color as some range from gold to yellow, orange to red, and chocolate brown to cream.
There are perennials and annuals, as well as bush, dwarf, seedless, and multi-headed varieties available.
For today’s post, though, we will be fusing on the most iconic of all – the giant sunflower. These can grow to over six feet in height with large, stunning flower heads.
It’s important to note that the growth timeline of a sunflower can vary depending on growing conditions, so you may find yours grows slightly differently compared to the stages outlined in this article.
Sunflower Growth Cycle – The Stages
A sunflower tends to grow in eight separate stages:
- The seeds are planted.
- The development of the seedling, leaves, and plant.
- Buds start to grow.
- Flowering begins.
- Pollination occurs.
- Seed development takes place.
- Finally, the harvesting process begins.
Let’s take a look at each stage in greater detail below.
Stage One – Planting The Seeds
On day one, the first stage is to plant the sunflower seeds. If you have seeds from a previous year, these are great to use.
If you’re starting from fresh, you can follow these steps with your chosen seeds (but remember, this is based on giant sunflowers).
The seed of a sunflower represents its undeveloped stage before the life cycle has begun properly. The seed will have a shell and this is essentially a dried out fruit from a sunflower plant.
Botanically, these seeds are referred to as a cypsela. Inside these seeds, all the genetic information and nutrients required for the plant to grow are present.
The seeds may be dormant but they are a source of life.
Stage Two – Germination
Once the seeds have been planted, the germination process begins. This typically starts on around day two and lasts until the tenth day after planting the seeds.
This is considered to be the first stage of the seed’s life in an awakened state.
Beneath the soil, the roots of the sunflower start to reach out and a shoot develops and pushes its way towards the surface in search of sunlight.
It is when the shoot appears above the soil that the sunflower is certainly growing.
Stage Three – The Development Of The Seedling, Leaves, And Sunflower Plant
From day ten to approximately day 35, the seedling has developed into a sunflower plant. This stage is where the plant develops and grows at its greatest amount.
For seeds planted indoors, this is the time to harden them off and transfer them outside. In most cases, this occurs toward the end of spring after the worst of the cold weather has gone.
When the young sunflower has sprouted, it will typically sport two small leaves.
As the stem grows taller, more leaves will start to develop and within this 25-day period, the first sets of oval-shaped sunflower leaves spread.
As more grow, they begin to resemble the heart-shaped leaves of mature sunflowers, but are not as large.
This stage of the plant’s development sees rapid growth as the sunflower eventually grows to its fullest and strongest self.
Stage Four – Buds Start To Grow
Around day 35 to 65 days, the sunflower becomes mature and is now strong enough to grow a bud.
This is one of the best times for any sunflower grower as seeing the buds grow is truly exciting.
It’s a sign that your care and preparation for the plant has worked perfectly and you can soon enjoy the beautiful splendor the sunflower will provide.
That being said, there are a few stages to go yet! Even at this stage, the sunflower is still developing. During this time, the flower requires as much energy from sunlight to grow good, strong buds and help them become larger.
This is why the sunflower needs as much sunlight as possible.
The sunflower follows the sun’s path in the sky – something called “heliotropism” – that’s right, the sunflower moves with the sun’s direction, trying to get as much of its light as possible.
Hydrating your sunflower is also critical at this point of its growth cycle. You need to water your sunflower regularly for it to grow buds and flower properly.
Stage Five – Flowering Begins
This is where you can really enjoy your sunflower’s glory at its best. Days 65 to 85 have seen the sunflower’s bud grow as large as it possibly can and it starts to flower.
This is also known as the “blooming stage” where the sunflower’s petals are introduced to the world. For a few weeks, you can bask in the sunflower’s beauty and enjoy your hard work and care.
Stage Six – Pollination
Stage six coincides with stage five from day 65 to 85. This is also when pollination occurs.
Not only is the sunflower at its glorious best during this period but it also attracts all kinds of pollinators who enjoy the countless disc florets paced with nectar.
Although numerous pollinators visit the sunflower, the vast majority of them are bees.
As they touch down on the florets, pollen sticks to their bodies and they then transfer this to another flower somewhere else. This, therefore, begins the pollination process.
Stage Seven – Seed Development Occurs
From day 85 to around 105, the fertilized seeds begin to develop and then ripen. This is a pivotal moment in a sunflower’s life cycle and everything so far has led to this moment.
The main goal of the sunflower is to produce as many healthy seeds as possible and fertilize other areas so sunflowers can grow.
At this stage, the head of the sunflower starts to turn yellow on its back. This is a sign that the seeds are starting to ripen. However, this process can take time, with some taking up to 125 days.
However, this depends on the variety of sunflower and the conditions it grows in.
The ripened seeds start to attract animals, such as birds, as well as insects that like to feast on the seeds. This is a joy to watch and why we highly recommend growing sunflowers as a way to feed the wildlife in your area.
You can choose to harvest at this point or leave the seeds to wildlife.
Stage Eight – Harvesting Begins
Days 105 to 125 are when the seeds have ripened and become ready to harvest. The glory days of the sunflower are gone at this point as the flower’s head droops and becomes brown.
This is the best time to harvest the seeds, whether they be for feeding wildlife through the winter months, for yourself, or for your pets.
To harvest the seeds, cut the stem around four inches beneath the flower head. Hold it upside down and store it in this position within a bag (ensure it is a breathable bag).
This should also be a dry space and away from any pets or wildlife.
Sometimes, you may find that an animal has gotten to the seeds already and consumed them all. But, if they haven’t, some seeds are likely to drop to the ground and nestle in the soil.
Throughout the winter months, the seeds will remain dormant before starting to grow again when the weather turns warmer.
When spring arrives, the seeds in the undergrowth may start to wake up. From here, they will start to germinate and the seedling of the sunflower will once again appear.
From here, the eight stages of a sunflower’s growth cycle begins again and you can enjoy the process for a second time!
Sunflower Growth Cycle Chart
Here’s a chart illustrating the eight stages of a sunflower’s growth cycle. Come back to this to check what stage your sunflower may be in by comparing yours with the image of the sunflower in the chart.
How Long Do Sunflowers Grow For?
Sunflowers typically take around 80 to 120 days to grow from seed to maturity, depending on the specific variety of sunflower and the growing conditions.
Some varieties may take longer or shorter than this range, so it’s important to consult the seed packet or the supplier for specific information about the variety you are growing.
Factors such as temperature, soil quality, water availability, and sunlight exposure can also impact the growth rate of sunflowers.
Common Issues When Growing Sunflowers
Growing sunflowers can be a rewarding experience, but like any other plant, they can encounter some problems. Here are some common issues that gardeners might face when growing sunflowers:
- Pests – Sunflowers are vulnerable to pests such as aphids, caterpillars, and weevils. These pests can damage the leaves and stems of the plant, and in severe cases, they can even kill the plant. Keeping the area around the sunflowers clean and free of debris can help reduce the risk of pest infestations.
- Diseases – Sunflowers can also be susceptible to diseases such as fungal infections, powdery mildew, and rust. Proper watering and air circulation can help prevent the growth of these diseases, as well as planting disease-resistant varieties.
- Stunted growth – Sunflowers need ample sunlight and water to grow properly. If they are not receiving enough of either of these, they may not reach their full potential.
- Floppy stems – Sunflowers with floppy stems can be caused by a lack of sunlight, or by a strong gust of wind. Staking the plant or providing some kind of support can help prevent this issue.
- Poor soil quality – Sunflowers require well-draining soil that is rich in nutrients. If the soil is too compact or poor in quality, the plants may not grow as well as they should. Adding compost or other organic matter to the soil can help improve its quality.
Overall, proper care and attention to growing conditions can help prevent many common issues when growing sunflowers.
Different Types Of Sunflowers
Altogether, there are many different types of sunflowers, each with unique characteristics and growing requirements.
There are actually around 70 species of sunflowers in the world, and not all look the same. Some are blue, purple, orange, and even brown.
But, it’s the yellow, sun-like common sunflower that is seen most worldwide.
The botanical term for a sunflower is “helianthus,” with “helios” meaning “sun” and “anthos” meaning “flower.” All flowers belonging to the helianthus species grow large flower heads and sport long petals, resembling the sun.
Below are some common types of sunflowers:
- Dwarf sunflowers – These sunflowers are typically less than two feet tall and have smaller blooms, making them a great choice for container gardens, and small garden spaces.
- Giant sunflowers – As the name suggests, these sunflowers can grow up to 12 feet tall and have large, bright yellow blooms. They are often grown for their seeds, which can be used for food or bird feed.
- Teddy Bear sunflowers – These sunflowers have fluffy, teddy bear-like blooms and are often used as a cut flower in bouquets.
- Red sunflowers – These sunflowers have deep red petals and a dark center. They are a popular choice for adding a pop of color to gardens and floral arrangements.
- Multi-colored sunflowers – This variety of sunflower has petals that are a combination of colors, such as yellow and red, or yellow and orange.
- Perennial sunflowers – Perennial sunflowers come back year after year and are often grown as a border plant or in large clusters for a dramatic effect.
- Pollenless sunflowers – Pollenless sunflowers are bred to produce little to no pollen, making them a good choice for people with allergies or for cut flower arrangements where pollen can cause a mess.
There are many other varieties of sunflowers, each with their own unique colors, shapes, and sizes. Some require a different care routine than others, but the stages of growth tend to be similar with most types.
Helpful Tips When Growing Sunflowers
It’s all well and good knowing the life and growth cycle of sunflowers but when it comes to caring for them yourself, there are some vital tips to know.
If you’re looking to grow sunflowers at home, check out these five tips. When the summer comes, your yard can hopefully be shining with a bloom of golden, sunny sunflowers!
1. Plant At The Right Time And In The Right Place
Sunflowers should be planted after the last frost date in your area. For best results, plant them when the soil has warmed up to at least 55 degrees Fahrenheit. We’ll go into this in greater detail below.
Also, sunflowers require at least six hours of direct sunlight per day, so choose a location in your garden that receives plenty of sun.
2. Water Frequently
It is imperative that you water your sunflowers regularly, particularly during their early stages of development and growth.
We recommend watering the plant in the morning before the sun reaches its hottest point of the day.
Also, allow for some space around your sunflower. The plant’s roots are quite extensive and grow as far as apart as 1.5 feet in some cases.
Therefore, the roots require enough room to grow sufficiently and properly. Without enough space, the root system will struggle to support the flower’s weight.
3. Prop Up Your Sunflower
Sunflowers can grow quite high. If your sunflower species is quite large, it could grow to three feet or more in height.
To prevent it from hanging down and drooping, support its stem with a stake, such as this. You can also use a long piece of thin wood you may have spare. Supporting the plant with a stake will help it grow strong and tall.
4. Trim The Leaves
Pests love the delicious seeds in the center of a sunflower’s blooms. Insects and birds are the main culprits of damaging sunflowers but you can avoid this by trimming the leaves that are closest to the flower.
Doing so makes it more challenging for insects to get in contact with the flower and enjoy its seeds.
5. Sow, Sow, Sow
We recommend sowing new seeds every couple of weeks during springtime. Do this and you can have a continuous supply of sunflower blooms until fall comes back around.
6. Deadhead Old Blooms
Remove spent blooms to encourage the plant to produce more flowers.
You can deadhead spent blooms of sunflowers at any time during their blooming period, but it’s best to wait until the flower head has completely finished blooming and begins to dry out.
A sign to do so is when the back of the flower head will turn brown and the seeds become visible. At this point, you can cut off the entire flower head and dispose of it or use it for decoration.
Moreover, removing the dead flower heads can help prevent diseases and pests from taking hold.
When Is The Best Time To Plant A Sunflower?
The best time to plant sunflowers generally depends on your location and climate.
Sunflowers need warm soil to germinate and thrive, so they should be planted after the last frost date in your area.
In general, sunflowers are planted in the spring after the soil has warmed up to at least 55 degrees Fahrenheit.
If you live in a region with a short growing season, you may want to start your sunflowers indoors two to four weeks before the last frost date and transplant them outside after the danger of frost has passed.
Sunflowers can also be planted in the summer for a fall harvest, but they will require consistent watering during hot, dry weather.
Sunflowers are quick growing plants that you can enjoy within a few months.
Plant yours at the right time and hopefully it will thrive and brighten your yard and days for many years to come!