9 Amazing Hacks For Growing Giant Sunflowers

If you are a keen gardener, then growing giant sunflowers is probably one of your dreams. There is something truly special about sunflowers, and they are the perfect flower for brightening up your garden.

However, it isn’t as easy as you might expect to grow sunflowers the size that you see in the movies. 

9 Amazing Hacks For Growing Giant Sunflowers

Sunflowers are fickle flowers that require a lot of tender loving care if you want them to grow to a large and impressive size.

You will need to watch over your sunflowers carefully and provide them with lots of different things if you want to grow gigantic sunflowers. Luckily for you, in this guide, we’ve compiled lots of excellent hacks that will send you on your way. 

In this guide, we’re taking you through 9 amazing hacks that will allow you to grow absolutely giant sunflowers. So, if you want your best chance of growing sunflowers that are going to make your neighbors jealous, read on to find out more!

1. Enrich The Soil Before You Plant

If you want to grow giant sunflowers, then the hard work will begin even before you plant your sunflowers. Many people make the mistake of planting their sunflower seeds into regular soil.

But if you do this, you are already putting your sunflowers at a disadvantage before they are planted. That is why you need to enrich the soil before you plant. 

Giant sunflowers will need a lot of nutrients in order to grow to their full size. Without these nutrients, the sunflowers simply will not grow as large as you want them to.

Enriching the soil before you plant the sunflowers essentially makes the soil as nutritious as possible. So, when you add your sunflower seeds to the soil, it really will give them the best possible chance in life.

Enriching the soil before you plant your sunflower seeds is comparable to taking prenatal supplements during pregnancy. The supplements will fill your body with additional nutrients, and your body will pass these nutrients on to the baby.

Likewise, enriching the soil with plant food (or something similar) will fill the soil with nutrients before you even plant your sunflowers in the soil. 

As well as enriching the soil, you also want to ensure that the soil isn’t compacted. Sunflowers are designed to start growing very quickly, and in order to do this, they will send out a tap root, followed soon after by a strong root system.

If the tap root isn’t able to penetrate the soil because it is compacted, this will prevent your sunflower seeds from being able to grow. So, the soil needs to be in good condition when you add the seeds. 

The enrichment will not stop when the sunflower seeds are planted. After you have planted your sunflower seeds, you must continue to enrich the soil with food and nutrients if you want your sunflowers to grow big and strong.

Your sunflowers will get all their nutrients from the soil, so the soil will need to be constantly enriched with nutrients throughout their lives to allow them to grow. 

There are lots of different types of plant food out there, and tons that come with different nutrients. If you have gardening experience, there is likely already a type of plant food that you like using.

However, if you are uncertain, any plant food will be perfect for enriching the soil before you plant your sunflowers.

2. Plant Sunflowers Known For Height And Avoid Dwarf Sunflowers

This next hack might seem like an obvious one, but you’d be surprised by the number of people who think that there is just one type of sunflower. Sure, most types of sunflowers look very similar, but there are actually tons of different types of sunflowers out there.

These different types of sunflowers have been bred for all sorts of different reasons. But a lot of the time, these sunflowers have been bred for size. 

Your average sunflower will grow to an average size. No matter how much enrichment you give it, or how much sunlight it receives, that sunflower will not grow larger than the measurements it was bred to reach.

That is why you cannot simply pick up just any old sunflower seeds from the store if you want to grow giant sunflowers. Instead, you need to plant sunflowers that are known for their height and size. 

There are tons of different breeds of “giant” sunflowers out there, so plenty for you to choose from when you are looking for seeds to buy.

If you have felt inspired to grow sunflowers because of your neighbor’s sunflowers that tower over the fence, then you are best off asking your neighbor what seeds they have used.

Neighborly competition is fine, but without the inside knowledge, your sunflowers will likely end up being considerably smaller than theirs!

Some of the best breeds of sunflowers to plant if you want giant sunflowers include: 

  • “Mammoth” sunflowers – a type of sunflower that can grow up to 12 feet in height. 
  • “Titan” sunflowers – this type of sunflower takes a long time to grow, but can reach more than 12 feet in height over a prolonged period. 
  • “Giant Primrose” sunflowers – the perfect type of sunflower if you want tall sunflowers that aren’t sparse.
  • “Mongolian Giant” sunflowers – one of the tallest types of sunflowers in the world, these plants can grow more than 14 feet in height. 

As you can see, there are lots of different types of giant sunflowers out there, and the breeds discussed above are just a handful of the options available to you.

But as well as choosing giant breeds, there is one other rule you need to follow when choosing your sunflowers. That rule is to avoid dwarf sunflowers. 

Just like many different types of flowers, sunflowers come in a variety of dwarf varieties, as well as giant varieties. If you want giant sunflowers, then you need to avoid dwarf varieties at all costs.

No matter how cute dwarf sunflowers may look, they will never grow into giant sunflowers because they are not bred to. So, if you want giant sunflowers, avoid dwarf varieties and ensure you buy seeds for a giant type of sunflower. 

3. Provide Your Sunflowers With Lots Of Sun

As the name suggests, sunflowers are flowers that require a lot of sunlight. Like all plants, sunflowers will chase the sunlight as they grow. So, if you want tall sunflowers, you need to plant them in an area that gets lots of sunlight.

If an area gets lots of sunlight, your sunflowers will simply grow straight up in the air, towards the sun. However, if the sunlight isn’t direct, you will often observe that your sunflowers grow at an odd angle and twist.

All plants are programmed to grow toward the sunlight, so your sunflowers will chase the sunlight at all costs. For that very reason, if you want tall and beautiful sunflowers, you will need to plant them in a good spot. 

If you live in an area with tumultuous and unpredictable weather, you are likely laughing at this hack. Of course, we know that you can’t control the weather, but what you can do is give your sunflowers the best shot in life.

That is why, before you plant your sunflowers, you should do some research in your garden to find the best spot for them. 

You might have a dream of where your sunflowers will grow in your garden, but if that spot doesn’t get any sunlight, your sunflowers will not grow.

Researching your garden and which spots get the most sunlight allows you to provide your sunflowers with a good home. Even if that home isn’t where you had first planned to plant them.

The “perfect” spot in your garden will be an area that gets full sunlight. By “full sunlight” we refer to a spot in the garden that gets sunlight for the entire day.

This area of your garden should be bathed in sunlight for around 8 hours each day, providing the flowers with an ample amount of sunlight each day. 

With some varieties of sunflowers, it is okay for them not to get full sunlight. For smaller varieties, less sunlight will not prevent your plants from growing and it will not limit their size. However, this isn’t the case for giant sunflowers. 

Giant sunflowers will require direct sunlight every single day if they are to grow to their full potential. Without this full sunlight, they will not grow into the giant sizes that you expect, regardless of how tall they are bred to become.

So, unfortunately, your bid to grow giant sunflowers may require you to compromise where you plant them in your garden.

4. Plant More Than You Need, Then Thin Them Out

So far, all the hacks we have looked at are things you need to bear in mind before you plant your sunflower seeds. So, let’s move on to some hacks to bear in mind when you are planting your sunflower seeds for the first time.

This first hack is a perhaps controversial one, but in our experience, it works incredibly well with giant sunflowers. 

You might have heard of the saying “less is more”, but this really doesn’t apply to growing sunflowers. When growing sunflowers, we would always recommend planting more than you need, and then thinning them out.

While the “less is more” saying can be applied to pretty much every other type of flower, it doesn’t apply when you are trying to grow giant sunflowers. That is because planting more seeds than you need will increase your chance of getting giant sunflowers. 

When it comes to growing giant sunflowers, thinning is important because it will provide the sunflowers you are growing with more root space.

When you have too many seeds in one spot, it can make growing difficult for the flowers, simply because of the competition associated with claiming root space. For sunflowers, this competition is even more difficult because they are such rapid growers. 

While there are some varieties of sunflowers out there that grow slowly, the vast majority grow very rapidly. So, very soon after planting, you will end up with lots of different sunflowers fighting for root space and sunlight.

Once your sunflowers start growing rapidly, you will need to thin them out. Otherwise, you might end up with lots of scraggly-looking sunflowers, rather than a handful of giant sunflowers. 

The process of thinning out allows you to keep the sunflowers that look like they have the best chance of growing to a giant size.

If any flowers look sickly, they should be the first ones to go. After that, you need to compare the sunflowers by height to pick out the tallest. 

If you want tall sunflowers, then your best chance of achieving this is to keep the taller flowers in the seedling stage, and thin out the shortest sunflowers.

If all your seeds were planted at the same time, then the plants that grow the quickest will have the best chance of growing into tall sunflowers when they bloom. So bear this in mind when thinning out your flowers.

5. Sow Directly Outside If Possible

Next up, we have another, somewhat, controversial hack and that is to sow directly outside if possible. Some people will have very strong opinions regarding sowing inside before transferring your plants outside.

However, in our experience, sowing directly into the ground in the garden is best if you want to grow giant sunflowers. 

When it comes to growing flowers, it is really easy to be tempted to get a head start on planting your sunflowers inside. However, in most cases, this will actually put you at a disadvantage when it comes to sunflowers.

Sunflowers grow rapidly, so there really isn’t any need to get a head start with these plants. You could simply plant them at the start of the outdoor sowing season, and you generally will not lose any time in terms of growth. 

The main reason why sunflowers thrive when sowed directly outdoors is that they struggle with being moved. If you sow your sunflowers outside, then they will remain in the same spot for the rest of their lives.

This allows them to become familiar with the soil, compete over root space, and have direct access to sunlight from the get-go. All of these things will allow your sunflowers to thrive. 

Sunflowers do not do well when their roots are disturbed. So, sowing inside and then transferring your sunflowers outside could actually damage the chances of you getting giant sunflowers.

All it would take is a small amount of damage to the roots, and that could prevent your sunflowers from rowing to their full potential. 

So, to make your chances of growing giant sunflowers as large as possible, we would recommend sowing them directly outside and allowing them to remain in that spot for the rest of their lives! 

6. Pinch Side Shoots To Direct Energy To Main Head

As your sunflowers grow, you will need to constantly monitor them to ensure they are getting enough sunlight, nutrients, and water.

Monitoring your sunflowers will allow you to keep an eye on how rapidly they are growing, and the hack to ensure they grow big and tall is to pinch the side shoots. 

If you want full sunflowers, then pinching the side shoots likely isn’t the best idea for you. However, if you have full sunflowers, you generally will not have tall sunflowers.

That is because sunflowers with multiple heads will have to split the nutrients and energy that they are receiving from the soil, water, and sunlight between the different heads.

So, if you want your sunflowers to grow tall, then you will need to pinch the side shoots. 

When you pinch the side shoots, the energy that the sunflowers receive will only be directed toward the main head of the sunflower. This will provide the main head with more than enough energy to grow really tall.

So, your sunflowers will have a much better chance of being tall and giant than if the energy is directed between multiple heads. 

Pinching side shoots on your sunflowers can be bittersweet. It’s not nice having to sacrifice one of the sunflower heads. But, if you want tall sunflowers, this is something that you will have to do.

If you are okay with smaller sunflowers, then there is no need to pinch the shoots. 

If you choose a variety of sunflowers that are bred for giant blooms, then a lot of these varieties tend to be single-bloom flowers. This means that they will not shoot outward with multiple heads, instead, all the energy will be directed toward the main head.

That is why these varieties have a better chance of growing giant heads, along with growing very tall! 

7. Provide Stakes Early On

When your sunflowers are just seedlings, there isn’t really any need to provide stakes. Instead, stakes only really need to be provided once the sunflowers have started to grow.

That being said, if you want your sunflowers to bloom with giant heads, and to grow as tall as possible, we would recommend providing them with stakes early on in the planting process. 

The earlier you provide your sunflowers with stakes, the straighter they will grow. If you provide them with stakes early on, your sunflowers will know exactly which direction they need to grow in.

They will grow straight up in the air because they have the stake for support, and this will make your chances of having super-tall sunflowers much better. 

One mistake that a lot of people make when growing sunflowers is that they provide the stakes far too late in the season. By then, the sunflowers have already started to find their way, but the lack of stakes can cause a lot of damage to the stem.

Sunflowers that are bred for height are not bred for their sturdiness. So, if they grow without a stake, the stem will likely bend and become damaged. 

As your sunflowers aren’t very sturdy, if they are hit by any stormy weather, such as strong winds, it could damage the sunflowers.

If the stems become damaged, your sunflowers will likely bend, and this will prevent your sunflowers from going tall. But stakes will help make your sunflowers sturdier, protecting them against high winds. 

In addition to providing stakes to your sunflowers early on in the season, we would also recommend planting the sunflowers in a shaded area.

By a shaded area, we do not mean an area shaded by sunlight, instead we mean a shaded area protected from strong winds. This will protect your sunflowers from damage, and increase the chances of them growing strong with giant heads. 

8. Protect Them As They Grow

While your sunflowers are growing, you will need to protect them at all times. This likely goes without saying, but it is so easy to forget to water your sunflowers from time to time.

This simple mistake could ultimately make the difference between your sunflowers growing tall and strong, and them not. So, protecting your sunflowers is really essential. 

If you are new to gardening, we’re sure you’ll be taken aback by just how much hard work goes into nurturing and protecting your plants as they grow.

Gardening is not for the faint-hearted, and if you are not prepared to get your hands dirty, planting sunflowers likely isn’t the best choice for you. 

Protecting your sunflowers will consist of a number of different things. At different stages of growth, your sunflowers will be under threat from different predators.

Early in growth, you will need to protect your sunflowers from things such as slugs, and as they grow creatures such as squirrels and birds will become threats to your sunflowers. 

You will need to protect your sunflowers from the very start, that includes when they are seeds. Seeds make very attractive snacks for birds, so they will easily jump at the chance to eat the sunflower seeds that you have freshly planted.

That is why you may need to cover the area with some netting immediately after planting your seeds. 

Before you even plant your sunflower seeds, you will likely have a rough idea of what creatures venture into your garden. You can use this information to your advantage to find different ways to protect your sunflowers throughout their life.

Protecting and taking care of your sunflowers really will give them the best shot of growing big and tall.

9. Keep The Seeds For Next Year

Finally, it is important to remember that sunflowers are seasonal. They will not grow back the next year unless you plant them, so unfortunately as winter rolls around, your sunflowers will die.

But fear not, your hard work wasn’t for nothing. In fact, you can use the seeds from your best sunflowers to plant new sunflowers the following year. 

Each sunflower you have grown will produce lots of seeds, so there is no need to keep the heads of all the sunflowers that you grew in the previous year.

Instead, we would recommend keeping the head of your tallest sunflower, and using this to plant new sunflowers the following year.

You already know that that sunflower grew nice and tall, so the chances are that the seeds of that sunflower will grow tall too. 

One mistake that a lot of people who are new to planting sunflowers make is failing to keep the seeds from the previous year.

This isn’t really the end of the world, but it will put you back a little as you will not know how tall the sunflower seeds you purchase will grow. 

With your very own sunflower seeds from the previous year, you are giving your sunflowers the best chance of becoming giant sunflowers. The seeds have come from a sunflower that grew really tall and large, so that is a great starting point.

If you care for your sunflowers next year in the same way that you cared for them this year, the chances are they will grow just as big as your sunflowers did previously. 

At the end of the season, it can be really easy to forget to keep the seeds from your sunflowers. However, we would always urge you to do so. We’re sure you won’t regret it! 


In short, there are lots of different things that you will need to do if you want your sunflowers to grow to giant sizes.

Sunflowers aren’t the easiest type of flower to grow, so if you are new to gardening, you might want to start with a flower that is a little more beginner-friendly. 

Sunflowers are beautiful once they have bloomed. However, a huge amount of effort and time is required if you want them to bloom into giant sunflowers.

If you want the best chance of growing large and beautiful sunflowers that will make your garden the envy of the street, check out the hacks we’ve covered in this guide. 

Thanks for reading!

Diane Peirce
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