How to Grow Sunflowers from Seed to Harvest

You want to grow sunflowers in your garden or on your balcony? Good news! It’s fairly simple and I give you all the information you need to grow sunflowers from seed to harvest in this article.

I exactly show you step-by-step what you have to do and also give you some additional tips at the end of this post.

Enough talk, let’s get started!

how to grow sunflowers from seed to harvest timeline

Table of Contents

Sunflower Plant Profile

Size (Height, Spread)5 to 9 feet tall and 2 to 3 feet wide.
ClimateSunflowers grow best with moderate temperatures between 70 and 80 degrees Fahrenheit.
Sun ExposureSunflowers like full sun.
Soil RequirementsSunflowers prefer neutral soil with a pH between 6.5 and 7.5.
Country of OriginNorth America.
Growing DifficultyEasy. Even total beginners can grow sunflowers in a decent manner.
Perennial?No, sunflowers are usually annuals.
When should you start to grow?You can start indoors as early as the middle of March or wait until 2 weeks before you expect the last spring frost if you want to start directly outdoors.
Expected Yield & HarvestYou can harvest up to 1 pound of sunflower seeds per plant.
Time from Seed to Harvest90 to 120 days to grow sunflowers from seed to harvest.
Pests & DiseasesCutworms, Wireworms, Thrips, Field Crickets, Alternaria, Rust, White Mold, Phoma, Head Rot.
What to do with it?You can use sunflower seeds for salads or even make your own bread out of them.

What Types and Varieties of Sunflowers can you grow?

Before we can go into the actual planning and growth process, you first have to decide which sunflower variety you want to grow.

I have listed the most popular sunflower types for growing below:

  • Sunforest Mix sunflowers
  • Skyscraper sunflower
  • American Giant sunflower
  • Sundance Kid sunflower
  • Little Becka sunflower
  • Teddy Bear sunflower
  • Moulin Rouge sunflower
  • Strawberry Blonde sunflower
  • Suntastic Yellow sunflower
  • Russian Mammoth sunflower

I personally love to grow the American Giant sunflower since it gets really big and I just love to see it grow.

Prepare the soil!

However, depending on your individual circumstances, you may rather want to rely on other sunflower varieties.

For instance, if you want to grow your sunflowers on your balcony, you might not have too much space in the vertical and may want to grow varieties that are smaller.

If you are not sure what variety you want to grow, you can also just pick different sunflower varieties and go for it.

It will be even more interesting if you plant different varieties since they will often look quite different in their shapes and forms.

When should you start to grow Sunflowers?

This depends whether you want to grow your seedlings inside or if you want to directly plant your seeds outdoors.

If you want to start growing your seedlings inside, you can start as early as in mid of March.

If you want to start outdoors without growing your seedlings inside, you should start when there is no longer the risk that temperatures fall below the freezing mark.

In moderate climatic zones, this usually is between the beginning and the end of Mai.

While it is easier to just plant your sunflower seeds outside instead of raising seedlings indoors, it also poses the risk that you seed too early and that your seedlings will die off due to adverse weather conditions.

Hence, if you really want to be sure that your sunflower seedlings make it, I would suggest you start indoors and start your growing journey between mid of March and mid of April so that your sunflowers will have enough time to grow in an optimal manner and to get really big until fall.

How long does it take to grow Sunflowers from Seed to Harvest?

It will usually take 90 to 120 days to grow your sunflowers from seed to harvest.

However, please note that this timespan is only true for experts who have plenty of experience in growing sunflowers.

If you are still a beginner, I would estimate more than the 120 days until you can harvest your sunflower seeds.

However, this is not a bad thing at all! Especially for sunflowers, it can be great to watch them grow since they will look quite impressive the bigger they get.

I personally love seeing my sunflowers grow much more than actually harvesting the fruits from them.

In fact, I often do not even remove the sunflower seeds when they are ready to harvest since they provide a great food source for birds.

If you do so as well, you will be surprised how many birds will actually come to your house 😉.

Thus, for me, growing sunflowers is not about quick wins.

It is rather about enjoying the process and I don’t care if it takes a little bit longer to get from seed to harvest or not.

In fact, I actually like when it takes longer so that I can watch my sunflowers grow for a longer period of time.

Consequently, don’t get impatient. Just let them grow the time they need to and let nature do its work.

What is the best Climate to grow Sunflowers?

Most sunflower varieties love moderate to warm climates to grow in an optimal manner.

However, thanks to seed companies and plenty of research, sunflowers have become quite resistant to almost all climatic conditions.

Hence, even though you might live in a rather cold climate, you will still be able to grow sunflowers, at least if temperatures in summer don’t drop below the freezing mark at night.

Thus, as long as you live in a rather moderate climatic zone, you are just good to go and you don’t have to worry about any issues regarding growing your own sunflowers.

What Temperatures do Sunflowers like?

Sunflowers grow best between 70 and 80 degrees Fahrenheit.

However, as mentioned before, many sunflower varieties are rather tolerant towards outside conditions and even if you can’t provide this optimal temperature range, chances are that you will just be fine as long as you don’t live in too extreme climatic zones.

What do you need to grow Sunflowers?

Although growing sunflowers is not difficult at all, there are still some things you need to grow your sunflowers in an optimal manner. This includes

  • Growing bed (only necessary if you want to grow your seedlings indoors)
  • Big flower pots (the bigger, the better; only necessary if you don’t have a garden to grow your sunflowers)
  • Sunflower seeds
  • Fertilizer (I recommend natural fertilizer; alternatively, you can also make your own fertilizer for which I give you the instructions in the following chapters)
  • Sticks and cord to stabilize your sunflowers
  • Potting soil
  • Slug fence
  • Watering can
  • Garden shovel
  • A little bit of patience 😉

What Yield can you expect when you grow Sunflowers?

As I mentioned earlier, growing sunflowers is not actually about the yield, but about the growth process itself.

However, to give you a rough estimate, you can expect to harvest between 0.5 and 1 pound of sunflower seeds per plant.

Yet, this is only a rough estimate and your yield will greatly vary depending on your skill level in growing plants as well as on the conditions you offer your plants.

Thus, don’t be disappointed if you yield less than what I listed as realistic goal.

In fact, I would not recommend caring about the end result too much.

I personally often don’t even harvest most of my sunflowers seeds and just leave them on the plants to give birds the opportunity to feed on them so that they can better survive the winter.

What Plants should you grow with Sunflowers?

To learn more about what plants to grow with sunflowers, make sure to check out my article that shows you the best and worst sunflower companion plants.

Why should you grow your own Sunflowers?

There are various different reasons why you should grow your own sunflowers.

In fact, while it is much more convenient to get your sunflower seeds from the store, you will miss out on many opportunities that come along with growing sunflowers.

First, you will not be able to enjoy the actual sunflower growth process.

In fact, for me, it is fascinating to see such a big plant growing from a rather tiny seed. I am always happy to see my plants grow and for many people, gardening is simply a quite nice hobby.

Second, you will not be able to learn about natural processes if you just get your sunflower seeds from the store.

By growing your own sunflowers, you will see from seed to harvest how sunflowers actually grow and you will understand much better how nature works.

Our ancestors have grown their own plants for many thousands of years and therefore, by growing your own plants at home, you can go back to the roots.

Third, growing your own sunflowers can also be beneficial since it can greatly reduce your stress level.

Especially if you work in a rather demanding job and are stressed quite often, you may need a break from time to time and growing your own plants can also be great in this regard since it is a pretty nice contrast to your daily work.

In fact, it can be quite peaceful to sit in your own garden and to watch your plants grow.

With lower stress levels, also your overall health level will likely improve.

Consequently, due to all those reasons, growing your own sunflowers can be a pretty good idea in my opinion.

Growing Sunflowers: Step-by-Step

1. Select a Site for your Sunflower Plants

I hope I convinced you that growing your own sunflowers is indeed a good idea. If so, we can now go into the actual planning process.

The first thing to do is to determine the optimal site to grow your sunflowers and to answer several questions in this regard.

Do Sunflowers like Sun or Shade?

Like the name already indicates, sunflowers indeed love the sun. Thus, make sure that you choose a sunny spot in your garden so that your sunflowers can grow in an optimal manner.

However, this doesn’t mean that your sunflowers need sun all day long. It just means that they get at least a few hours of sunlight every day.

Therefore, even though you might not have a spot in your garden that provides sun all day long, you will just be fine if you provide sunlight for a few hours to your sunflowers.

What are the Soil Requirements of Sunflowers?

Sunflowers are quite flexible regarding the soil they grow in. As long as the soil is relatively neutral in terms of acidity and waterlogging is not present, sunflowers will grow in a satisfying manner and are not picky at all.

Thus, by just using conventional potting soil from your garden store or by planting your sunflowers directly into your garden, you will just be fine and don’t have to worry much about adding additional components to the soil.

How much Space do Sunflowers need?

Sunflowers can get really big. And when I say big, I mean big 😉. Even though they will not need too much space in the horizontal, sunflowers can reach extreme heights of 10 feet or even more.

Hence, it is crucial that you make sure that your sunflowers have sufficient space into the vertical.

Also make sure that each sunflower plant has at least 3 feet space to each side in the horizontal so that your sunflowers don’t have to compete for nutrients or sunlight with each other and can grow in an optimal manner.

If you have a big garden, feel free to give your sunflowers as much space as you want.

In fact, the more space your sunflowers have, the better they will develop.

Consequently, if you have more space, why not using it?!

Should you plant Sunflowers in a Pot or in the Garden?

While it is possible to grow sunflowers in a pot, I would not recommend it unless you don’t have any other alternatives.

The reason for this is that your sunflowers will get quite big and you will also need a pretty big pot to provide your sunflowers with sufficient soil so that they can grow in an optimal manner.

Sure, if you don’t have a garden and still want to grow sunflowers on your balcony, you will simply have no other choice than growing your sunflowers in a pot.

However, if you have a garden, I highly suggest you just grow your sunflowers there since it will make your life much easier and your sunflowers will also have more soil and space to grow in an optimal manner.

2. Plant Sunflower Seeds

After selecting the optimal side for your sunflowers, it is time to start with the actual seeding process.

Should you buy Sunflower Seeds or Seedlings?

When it comes to sunflower seeds, you have to decide whether you want to grow your sunflower from seeds or if you rather want to buy seedlings from the garden center instead.

In fact, not many garden centers will sell sunflower seedlings, since there is just not sufficient demand for sunflower seedlings in the general public and that for a good reason.

Growing sunflower seedlings is so simple that people just do it by themselves and you should do so as well.

In fact, I will show you everything you need to know to grow your sunflower seedlings in an optimal manner in the following chapters.

Should you buy Sunflower Seeds or produce Seeds by yourself?

If you haven’t grown sunflowers before, you will simply have no other choice than to buy your sunflower seeds online or from your local garden center.

In fact, you have to grow your first sunflowers before harvesting your own seeds.

Thus, for your first year of growing sunflowers, just order your seeds and you are good to go.

For the next years, you can just use the seeds you will harvest from your sunflowers this year and you can continue to do so into perpetuity.

How to plant Sunflower Seeds

Now that you got your sunflower seeds, it is time to start planting your seeds and to start the actual growth process.

As mentioned before, you have to decide whether you want to grow your sunflower seedlings indoors and transplant them to your garden after a few weeks or if you just want to start outdoors from the beginning.

If you want to start growing your seedlings indoors, just start around one month before the last freezing night in your region.

You can just fill your growing bed with potting soil. After that, just place your sunflower seedlings onto the soil surface.

Make sure that each seed has at least 4 inches of space in each direction so that your sunflower seedlings can grow in an optimal manner.

After you placed your sunflower seeds accordingly, you just have to cover them with an additional potting soil layer of around one inch in height.

Finally, just place your growing bed at a bright and warm spot in your house and you are good to go. Also make sure to water your growing bed on a regular basis and never let your growing bed dry out.

Alternatively, if you want to start growing your sunflower seeds outdoors, wait until the last freeze of the year is over and just plant your seeds right into your garden.

You just have to dig some small holes and leave at least 3 feet of space between each seed so that your sunflowers will have enough space when they finally turn into big plants.

After you are done, you just have to water your seeds on a regular basis.

How long does it take to see the first Sunflower Seedlings?

If you grow your sunflower seedlings indoors, chances are that you will see the seedlings a little bit quicker compared to just planting your seeds outdoors into your garden since it will simply be warmer inside your four walls.

While I would expect you to see the first seedlings in your growing bed inside your home in just one week, it can take a little bit longer outdoors.

In both cases, it can take up to one month until all seedlings will reach the soil surface.

However, please note that not all seeds will turn into seedlings. In fact, some seeds will just rot instead.

Thus, if you don’t see any seedlings after one month in some spots in your garden, it is time to add additional seeds to those spots if you want to use your space in an optimal manner.

How to protect your Sunflower Seedlings

While you don’t need to protect your sunflower seedlings if you grow them indoors, you will have to take some additional protection measures if you grow them straight into your garden.

In fact, small seedlings are quite vulnerable to all kinds of outside conditions and you should definitely protect your seedlings outdoors from snails and other unwanted creatures who will try to feed on your sunflowers.

The best and easiest way to protect your seedlings that doesn’t require the use of chemical substances is just to use slug fences.

In fact, slug fences are not only suitable to protect your seedlings against snails, but they may also deter other small animals.

When should you transplant your Sunflower Seedlings?

If you decided to start growing your seedlings inside your four walls in a growing bed, it will be time sooner or later to transplant your seedlings outdoors into your garden or into a big pot.

In my opinion, you should wait to transplant your sunflower seedlings until two main criteria are met. The first criterion refers to the size of your sunflower seedlings.

The bigger they are, the more resistant your sunflower seedlings will get and the better the chances that they will stay alive once you transplanted them outdoors.

I would suggest you wait until your sunflower seedlings reach a minimum height of at least 10 inches. The second criterion refers to the overall outside conditions.

If the temperatures still drop below the freezing mark, it is not time to transplant your seedlings outdoors yet.

In fact, you should wait until this will no longer be the case since your sunflower seedlings will still be relatively sensitive to freeze. If both criteria are met, you can start transplanting your seedlings outdoors.

Before you actually do so, you have to prepare your growing site in your garden. Similar to just starting to grow your sunflowers from seed right in your garden, you also have to dig one hole per sunflower of at least 3 feet in the horizontal.

After that, just place your seedlings into the respective spots your garden and cover their roots with potting soil. Finally, you just have to water your seedlings.

3. The Sunflower Growth Process

Now that you have grown your seedlings to a certain height and in case you stated indoors, also transplanted them outside, the hardest part is already done.

From now on, your sunflower will grow rather quickly and will also become less vulnerable to slugs and other harmful outside factors as well.

However, even though the most difficult steps are done, there are still some things to consider for the future growth process which I talk about in the following.

Should you prune your Sunflower Plants?

Many people are not sure whether they should prune their sunflowers.

I am personally not a big fan of pruning at all since it is kind of unnatural and I think you should rather let your plants grow and let nature do its work.

Especially when it comes to sunflowers, there is no need to prune them at all and you can actually do more harm than good by doing so.

Hence, just let them grow and enjoy the process instead of interfering too much with natural processes.

Do you have to pollinate your Sunflower Plants by Hand?

You also don’t have to worry about pollinating your sunflowers by hand.

In fact, since there will be many insects around in your garden or on your balcony, you can just let your sunflowers grow and the insects will help you pollinate your sunflowers in a completely natural manner.

In this regard, it is also crucial that you don’t use chemical substances for your growing project in order to protect those insects and to ensure natural pollination in the long run.

How to stake your Sunflower Plants

Since your sunflowers will get quite big, it is crucial that you stake them so that they get enough stabilization and don’t snap sooner or later.

In order to stabilize your sunflowers, you just need to anchor big bamboo sticks next to each sunflower and tie your sunflowers to those sticks.

Make sure that you make a tie for each foot in the vertical so that your sunflowers are stabilized in the best possible manner and are less vulnerable to heavy winds or other extreme weather conditions.

4. The Sunflower Harvest

After you did all the work and followed all the steps in this article, you should have been able to grow decent sunflowers.

In late summer or early fall, your sunflowers should finally be ready to get harvested.

When should you harvest your Sunflowers?

It is pretty simple to determine the optimal harvesting time for your sunflowers.

In fact, you just have to harvest one sunflower seed and have a look at it. If they look like the seeds from the store, they are ready to harvest.

However, as mentioned before, I don’t recommend to harvest all of the seeds from your sunflowers.

In fact, I would leave part of those seeds in the plant for birds who can feed on them.

Hence, do nature a favor and just leave part of your sunflower seeds inside your plant.

How to store your Sunflower Harvest?

Storing your sunflower seeds is pretty simple. You can just put them in a box or in a big bag and store it at a dark and dry place inside your home.

If you store your sunflower seeds properly, they will last many months or even years.

You can even reuse part of your yield for future sunflower growing projects and do no longer have to rely on seeds from seed companies.

What should you do with your Sunflower Seeds?

While you can harvest plenty of seeds from your sunflower plants, many people actually don’t really know what to do with them.

If you are really ambitious and curious to try new things, you could just grind your sunflower seeds and try to make your own bread.

You can also use your sunflower seeds to make your own pesto.

You can also just crack them and eat them like they are.

Either way, sunflower seeds are quite healthy and can also taste quite well.

Sunflower Plant Care Tips

While you have already got most of the information to grow sunflowers in an optimal manner, there are still some general things missing which I will discuss in the following.

How often should you irrigate Sunflowers?

While sunflowers like a lot of sun and also need plenty of water on hot summer days, you should still make sure that they don’t get waterlogged.

In fact, sunflowers hate being waterlogged since their roots can begin to rot due to that.

Hence, make sure that the soil you plant your sunflowers in is loose enough so that excess water can ooze away rather quickly.

You are also rather flexible regarding when to water your sunflowers. You should basically provide your sunflowers with water whenever they need it.

You can often see when it is time to water your sunflowers by just having a look at their leaves.

If the leaves start to hang, this is often a sign that your plants need water.

You can also just dig a small hole with your finger into the soil next to your sunflowers.

If the soil doesn’t stick to your finger, it is an indication that the soil is dry and you should water your plants.

Over time, you will get a pretty good feeling of when it is actually time to water your plants.

Thus, don’t stress out too much over this topic.

Chances are that you will be just fine.

At what Time of the Day should you water your Sunflower Plants?

The best time to water your sunflowers is arguably the early morning. This is not only true for watering sunflowers, but also for many other plants.

However, in my opinion, it doesn’t make too much difference whether you water your plants in the morning or in the evening.

I suggest you water your plants whenever they need it instead of relying on fixed watering times.

How often should you fertilize your Sunflower Plants?

Since sunflowers will get quite big, they also need plenty of nutrients to grow in a healthy manner.

While your soil often already contains plenty of nutrients, it will often not be enough for sunflowers to grow in a healthy manner.

Hence, you should fertilize your sunflowers on a regular basis.

What kind of Fertilizer should you use for your Sunflower Plants?

While it can make quite a lot of sense to fertilize your sunflowers to improve the overall growth behavior of your plants, you should not use any chemical fertilizer to promote plant growth.

Yes, those chemical substances work. However, they also lead to significant soil pollution and can make your soil less fertile in the future.

Consequently, instead of using chemical fertilizer, try to rely on organic fertilizer instead. You can just buy such organic fertilizer online or from your local garden center.

Alternatively, you can even make your own fertilizer. It is actually quite easy to do so. You just need to go to your local forest and collect some stinging nettles.

After you come home, just put those stinging nettles in a bucket and cover them will tap water.

After a few days, just remove the plant material and you will have a great natural fertilizer full of nitrogen and other substances that promote plant growth.

You can just add this natural fertilizer to your watering can and you are good to go.

Should you use Pesticides or Herbicides for Growing Sunflowers?

Similar to the use of chemical fertilizer, I also don’t recommend you to use any chemical pesticides and herbicides.

In fact, those substances are quite harmful to many insects and can decrease the population of bees and other organisms that are quite helpful in gardening.

Thus, just remove unwanted weeds by hand instead of using chemical herbicides.

To deal with pests, you can just use your stinging nettle liquid and spray it onto your plants.

In fact, stinging nettle liquid is not only a great fertilizer, it is also a great pesticide since pests don’t like the taste of stinging nettle liquid at all.

Consequently, there is simply no need to use chemical substances for growing sunflowers and you should rather rely on organic alternatives instead.

If you want to learn more about pest control, you should also have a look at how to control sunflower pests and plant diseases.

What’s left to say?

What’s left to say is that I am really thankful that you got to this point of the sunflower growing guide!

Honestly, I know that my growing guides are quite extensive.

However, it is important to me that I provide you with all the information you need to grow sunflowers from seed to harvest in the best possible manner.

I hope you liked this article. If you did, make sure to also share it with your family and friends and also via social media.

Also feel free to read my growing sunflower FAQs to get even more information on growing sunflowers at home.

Sources

https://en.wikipedia.org/wiki/Helianthus

https://www.britannica.com/plant/sunflower-plant

https://www.healthline.com/nutrition/sunflower-seeds

About the author

My name is Andreas and I’m really passionate about our environment and also about growing plants. In fact, I have grown several different plants over many years. I love to see my own plants grow and always try new things.

In my blog posts, I want to share my experiences with you so that you can become successful in growing various different plants, even if you are still a beginner right now.

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