Why Do Your Sunflowers Not Have Seeds? 5 Reasons

There are many benefits to growing sunflowers. Not only are they beautiful, but they produce many seeds that make delicious snacks. If your sunflowers don’t have seeds, what could be the cause? 

Sunflowers may not produce seeds if they cannot pollinate or are nutrient-deficient. Inadequate nutrients or sunlight can cause your sunflower to show signs of stunted growth by producing no or very few seeds. 

Let’s dig deeper into why your sunflowers may not produce seeds and how to help fix this for next year. 

1. No Pollination Occurred

Sunflower seeds serve many great uses for humans, but if they have not been pollinated, they will not grow. Pollination happens when bees carry pollen from the male row on the flower to fertilize the female row. 

In the absence of bees, this process cannot happen, and the sunflower will not go on to develop seeds. 

The problem with no pollination is that you may not even notice the difference until you look for seeds. Sunflowers will continue to grow even without the pollination process occurring. It can be difficult to notice that no pollination is taking place unless you consistently watch for bee activity or notice no seeds. 

Nectar and pollen and the bright petal color attract insects to sunflowers. Nectar provides bees with energy to allow them to pollinate. Meanwhile, pollen provides vital nutrients for the bees’ survival. So, there are plenty of reasons for bees to come looking for sunflowers. 

Thankfully, there are many ways to attract bees to your garden, which I will cover below:

Ways To Attract Bees to Your Garden 

Here are some easy ways to entice bees into your garden:

  • Avoid pesticides that can deter and kill the bee population in your garden.
  • Grow more plants like sunflowers that attract bees.
  • Leave branches and twigs nearby for bees and birds to create nests.
  • Fill a shallow bowl or birdbath with water in your garden (this will attract both bees and some beautiful bird species).

Where Are All the Bees?

You are not alone if you have difficulty attracting bees to your garden. Beekeepers have reported overall lower numbers in bee colonies. The problem lies in the decline in the bee population overall. 

Fewer bees may not seem like a big deal, but this decline can greatly impact the ability of bee colonies to find new food sources. Hives will send scout bees to find new places to set up their hives. With fewer bees, fewer scouts may be available to look for new places, like your garden. Bee colonies may be unable to venture out as far as looking for new homes. 

2. Something Else Got the Seeds First

If you notice that there are no seeds in your sunflowers, you may have an animal or pest problem. Even if the sunflower did produce seeds, you might not have found them before another animal decided to enjoy them. 

This is, unfortunately, quite common as there are many different animals besides humans that eat sunflowers. Other animals are drawn to sunflowers the same way that insects are. They are bright-colored and eye-catching, and many animals know they produce delicious seeds. 

Sunflowers also do not produce a scent that can keep animals away, making it safe and enticing for them to come by and snatch some seeds. 

Animals That Eat Sunflower Seeds

  • Birds
  • Mice
  • Squirrels
  • Chipmunks
  • Bears

Based on the animals you notice nearby, you may easily judge what is taking your sunflower seeds. Of course, you would know if bears frequent your garden. However, the other animals on the list are a lot more discreet. 

How To Prevent Animals From Eating Your Sunflower Seeds

You can attempt to keep animals away from your sunflower seeds in a few different ways. 

One way is to build a fence around your sunflowers to keep most of these animals out. While a fence may not be ideal for small mice as they may still find a way in through gaps in the fence, it can keep most of the bigger animals out. 

Birds are quite tricky to keep out, though. They somehow help with the pollination process as the pollen stick to their bills or feet and fall off on other flowers as they hop from one bloom to another. 

However, it’s best to keep out birds that can attack bees while feeding on sunflower seeds, such as woodpeckers and northern cardinals.

It can be challenging to prevent birds from getting to your sunflowers. Since sunlight is essential to these flowers, you should avoid using bird-deterrent methods that involve shading. Covers might also prevent bees from getting to your sunflowers.

Look for a cover that will allow sunlight in or weigh the risk of covering your sunflowers and blocking the sunlight and pollinators they need. 

3. Not Enough Sunlight

Sunflowers certainly live up to their name, requiring at least six hours of sunlight per day. If you want them to truly thrive, they should get about eight hours of direct sunlight per day. 

Without adequate sunlight, sunflowers will not thrive. They may still grow, but you may notice stunted growth. They may also be quite weak, given the lack of energy provided by the sun. 

Malnutrition and lack of sunlight can prevent sunflowers from creating seeds. Even if they can produce some seeds, the lack of proper sunlight can affect how many they produce. You may be stuck with little to no seeds as a consequence of your sunflower not getting enough sun. 

This is why you should be mindful of where you plant sunflowers and why you may not want to cover them. Sure, covering your sunflowers can keep birds from stealing the seeds. However, doing so in a way that blocks the sunlight they need to thrive is counterproductive. 

How Much Sun Is Too Much?

With the constant need for six hours of sunlight at minimum per day, you may wonder how much sun is too much. Thankfully, too much sun for a sunflower is rare. However, it is still possible. So, here’s what you need to watch out for. 

Sunflowers can handle plenty of sun throughout the day, but you should consider limiting sun exposure on very hot days. If the temperature is above 90 °F (32.2 °C), you should partially shade your sunflowers throughout the day to help keep them from drying out. 

Also, ensure that your sunflowers have plenty of water during hot days to keep them hydrated. The only time you really have to worry about sunflowers getting too much sun is during extreme heat like in the peak of summer. Otherwise, feel free to let them enjoy their sunny days without interference. 

Signs of Too Much Heat

  • Wilting
  • Petal discoloration
  • Yellow, brown, or black leaves
  • Stunted growth

While there are many different possible reasons your sunflower may exhibit one or more of the above signs of distress, too much heat can cause each of them. So, keep an eye out for these signs and monitor the changes in temperature. 

If you think overheating is the reason that your sunflowers aren’t producing seeds, consider covering them for a short time during the day. I recommend doing so in mid-day when the sun is too hot and bright. Allow your sunflowers to bask in the morning and late afternoon sun.

4. Not Designed for Pollination

Another reason you have seedless sunflowers could be due to their cultivar. While ordinary sunflowers pollinate to form and spread their seeds, some varieties of sunflowers do not pollinate. Pollenless sunflowers make excellent alternatives to pollen-containing varieties. 

You may be wondering if it is possible to have a pollenless sunflower without realizing it, and simply put, the answer is yes. Pollenless sunflowers are very similar to ordinary sunflowers. They can have a similar look and feel but no pollen to create seeds with. This can make them difficult to differentiate until they mature. 

Where Pollenless Sunflowers Came From

Pollenless sunflowers were first created by chance in the late eighties. Ultimately, they weren’t supposed to come about at all, but they became quite popular, with allergies on the rise due to pollen. The lack of pollen meant they would produce no seeds and be a better choice for allergy sufferers. 

These flowers were artificially created and not meant to make it very far. But they did. Today, you can find pollenless sunflowers in many places. 

How Can I Tell if My Sunflowers Are Pollenless?

Now that you know about pollenless sunflowers, you may be wondering how to tell them apart from ordinary sunflowers. 

First, you will know when it comes time to pollinate. Your pollenless sunflowers will produce no seeds. But there are other ways to differentiate them as well. 

Pollenless sunflowers tend to grow with one bloom for every stem. Most ordinary sunflowers will branch out from one stem and grow multiple blooms. If you have one stem with one bloom, you are most likely dealing with pollenless sunflowers. While not every variety of pollenless sunflowers grows that way, it is overwhelmingly common. 

Remember, bees will still come to your pollenless sunflowers as they still carry nectar. You will still see bees around your sunflowers, no matter their pollen content. Just remember that pollen is very important for the nourishment of bees—they are missing out on nutrients by feeding off of your pollenless sunflowers. 

How To Get Pollenless Sunflowers To Regrow

If you choose pollenless sunflowers for your garden, there are only a couple of ways to get them to come back again. First, you’ll need to order and replant pollenless sunflower seeds because they don’t produce seeds themselves. 

You’ll have to handle the regrowth of your sunflowers without the help of pollination. 

Alternatively, you can have seeds grow from pollenless sunflowers if there are ordinary sunflowers nearby. Bees still flock to pollenless sunflowers because of their bright color and the nectar they offer. Use this to your advantage by planting ordinary sunflowers nearby.

If you decide to do this, the bees will transfer pollen to your pollenless sunflower varieties. This will provide them with missing pollen and allow them to grow seeds like other sunflowers can. While this is a great way to improve the chances of your seedless sunflowers regrowing, it is not a guarantee.

5. Nutrient Deficiency

Finally, your sunflowers may not produce seeds if they have a nutrient deficiency. While we discussed the dangers of not getting enough sunlight, there are other nutrients that sunflowers rely on to grow tall, remain sturdy, and grow seeds. 

There are quite a few nutrients that sunflowers require, though not all of them need to be in large quantities. Most notably, nitrogen, phosphorus, and potassium are the major nutrients required by sunflowers to help them grow optimally and produce seeds when it comes time for pollination. 

These nutrients should exist in large quantities in your garden soil. You may need to supplement your garden with these nutrients through balanced fertilizers. Without a good amount of these nutrients, your sunflowers may not produce as many or even any seeds. 

Some other nutrients worth mentioning are calcium, sulfur, and magnesium. However, sunflowers can get these in decent amounts if you have fertile garden soil. This means that human intervention with these nutrients is rarely necessary. 

Nutrient Boost

If you need to give your sunflowers a nutrient boost, you can do it in another way. If your sunflowers need calcium, sulfur, or magnesium, consider amending the soil they are in. All you need is to add some fresh soil or compost to the mix, and they’ll get those nutrients naturally. 

For potted sunflowers, you can apply a balanced fertilizer (10-10-10) or a phosphorus-rich fertilizer (10-30-10) with trace amounts of micronutrients. You may also consider additives and sprays for a more direct approach to adding missing micronutrients.

How To Identify Specific Nutrient Deficiencies

You don’t need a complicated test or an expert opinion to identify a specific type of nutrient deficiency in sunflowers. The symptoms of lacking each nutrient present differently and are pretty easy to identify. 

  • Magnesium: Yellowing of the older, lower leaves first, eventually moving up to newer leaves as it worsens. 
  • Calcium: Newer leaves are small with black tips. 
  • Nitrogen: Smaller compared to healthier sunflowers, leaves, and stems will also be a pale green rather than bright. 
  • Phosphorus: Leaves will turn darker, deeper green, eventually turning yellow.
  • Potassium: Stunted growth of leaves, yellowing near the veins of older leaves. 

The Benefits of Seedless Sunflowers

There are quite a few benefits of sunflowers that don’t include their seeds. While you may miss out on the food source, you can still reap plenty of benefits from growing them. With seedless sunflowers, you have a beautiful-looking flower. 

Seedless sunflowers can come in many different beautiful colors and varieties. Below are a few examples of seedless sunflower types: 

  • Orange Sun
  • Double Quick Orange
  • Claret
  • Sunrich
  • Starburst Lemon Aurora
  • Buttercream

These make beautiful additions to any garden or flower bouquet.

The term seedless sunflower is often used interchangeably with pollenless sunflower. However, that is not always correct. Remember that there are plenty of reasons your sunflowers don’t have seeds, and being a pollenless variety is just one of them.

It’s also worth noting that while they still produce nectar, pollenless sunflowers do not have pollen. They are a much better option for people with pollen allergies.

Some seedless sunflowers may still produce some pollen, but the amount is too low for it to trigger allergies. 

Seedless sunflowers can also be beneficial to farmers. Whether they use their tall stalks to protect other crops from the wind or just sell the flowers to a local florist, farmers can find many uses for sunflowers, whether they are seedless or seeded.

Which Sunflowers Produce the Most Seeds?

If your sunflowers yielded little to no seeds, you might wonder which type of sunflowers to choose that produce the most seeds. 

Typically, larger sunflowers produce more seeds because they have more room t o grow them. You can also count on larger sunflower types to produce larger seeds that are more fit for human consumption. 

Ordinary sunflowers can sometimes grow multiple flowers per seed. These will yield the most sunflower seeds as there are multiple flowers to work with from just one stalk. This means that there are different ways to ensure you get the most seeds from your sunflowers. 

Types of Sunflowers That Tend To Produce the Most Seeds

  • Mammoth Russian
  • Giganteus
  • Kong Hybrid
  • Titan
  • Royal Hybrid
  • Hopi Black Dye

These are just a few examples of sunflowers that produce the most seeds. Keep in mind these types of sunflowers are also the largest, making them difficult to manage in smaller gardens. The varieties listed above range in size from 7 to 15 feet (2.1 to 4.6 m) tall. 

Final Thoughts

There could be various reasons why your sunflowers lack seeds, such as failure to pollinate, inadequate sunlight, animal consumption, and nutrient deficiency. Sometimes, it could be because you may have unknowingly bought a pollenless variety from your plant supplier.

You must check carefully the type of sunflowers you buy to help avoid pollenless sunflowers if you want to have sunflowers seeds for snacking or selling. Also, ensure that your sunflowers have enough nutrients and plenty of sunlight during the day so they grow as healthy as possible.

Alexander Picot

Alexander Picot is the principal creator of TheGrowingLeaf.com, a website dedicated to gardening tips. Inspired by his mother’s love of gardening, Alex has a passion for taking care of plants and turning backyards into feel-good places and loves to share his experience with the rest of the world.

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