When to Harvest Sunflower Seeds

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Here we're turning our attention to a summer and autumn favorite: the radiant sunflower.

Known for its cheerful, broad face and vibrant color, the sunflower does more than just beautify our gardens and homes. Hidden within each large flower head is a bounty of seeds, ready to offer both a nutritious snack and the promise of more sunflowers in the future seasons.

But how do you know when and how to harvest these seeds?

In this comprehensive guide, we'll explore the journey from blooming sunflowers to a successful sunflower seed harvest.

We will answer common questions like when to harvest sunflower seeds in the UK, how to prepare the seeds for planting next year, or how to best serve the seeds to our feathered friends. Here we will aim to provide you with the knowledge needed to effectively harvest and store sunflower seeds.

So, if you've ever gazed at a sunflower and wondered about the next steps, or if you're simply interested in trying something new in your garden, read on. Let's dive into the world of harvesting sunflower seeds.

To learn more about growing sunflowers, check out my guide to the best time to plant sunflowers.

Harvesting sunflower seeds with several seeds collected in a large basket

The Sunflower Harvesting Season

Sunflowers are a beloved part of many gardens, serving not just as beautiful flowers but also as a source of nutritious seeds. Typically, the harvesting period for sunflower seeds in many regions, including the UK, occurs from late summer to early fall.

Depending on your region's climate, the specific month may vary, but generally, it's when the back of the sunflower head turns brown.

Sunflowers, with their iconic, vibrant blossoms, are typically annual plants, meaning they complete their life cycle in one growing season. This cycle includes sprouting, flowering, and seed production.

Sunflower seeds are generally sown in the spring once the threat of frost has passed. The plants grow throughout the warm summer months, using their large leaves to soak up sunlight.

During this time, their stalks thicken and grow tall, and the recognizable flower heads form and unfurl their bright yellow petals.

The actual sunflower harvesting season typically begins in late summer and extends into early fall. The precise timing depends on your local climate, the specific sunflower variety you're growing, and when the seeds were initially planted.

As the flowers mature, their petals will begin to wilt and fall off. The flower heads will start to droop, and the back of the flower (the seed head) will turn from green to a brownish color.

These are all indications that the seeds inside are nearing maturity and will soon be ready for harvest.

It's worth noting that sunflower seed heads mature from the outside in. If you examine a mature sunflower head, you'll notice that the outer rim of seeds appears mature first, while the seeds near the center are the last to fully develop.

This can create a brief window of time where some seeds are perfect for harvesting while others need a bit more time.

While it's possible to leave the flower heads on the plant until all the seeds have fully matured, many gardeners prefer to cut the heads off once most of the seeds have matured to protect them from birds and other wildlife that also enjoy sunflower seeds.

As we approach the end of the season, harvesting should be completed before the first frost of winter. Frost can damage the seeds and make them less viable for planting or eating.

To sum up, the sunflower harvesting season is a period of watching and waiting as nature does its work, followed by a flurry of activity as you gather the fully matured seeds. It's a process that requires patience and care, but the reward—whether it's a jar full of ready-to-eat seeds or a sack full of potential new growth for next year—is well worth the effort.


My favorite sunflower seeds for planting:


a bright yellow sunflower with seeds ready for harvest

When to Harvest Sunflower Seeds for Planting Next Year

Sunflower seeds harvested for replanting need to be fully mature. Fully mature seeds have the highest chance of germination, meaning they're most likely to sprout and grow into healthy new plants.

Harvesting seeds for replanting involves a delicate balance. You want to give the seeds as much time as possible to mature on the plant, but you also want to harvest them before they're eaten by birds or destroyed by poor weather conditions.

As I mentioned earlier, sunflower seeds are generally ready to harvest for planting purposes when the back of the sunflower head has turned from green to brown, and the yellow petals have dried out and fallen off. The seeds themselves should look plump and hard, with black-and-white striped shells.

If you press a fingernail into a seed, it should resist splitting and not dent easily.

It's important to remember that not all seeds will mature at the same rate. Seeds around the edge of the sunflower head will usually mature before those at the center. You might need to make a judgment call on when the majority of seeds appear mature and ready to harvest.

After you've harvested the seeds, you'll need to let them dry out for several days in a warm, dry place. Spread the seeds out on a flat surface, such as a baking sheet, so they're not touching each other.

This allows air to circulate around each seed, helping them to dry out thoroughly. Remember, fully dried seeds are less likely to mold, making them safer to store.

Finally, store the seeds in a cool, dry place until you're ready to plant them. A paper envelope is a good storage solution, as it will allow any residual moisture to escape.

Don't forget to label your seeds with the date of harvest and the variety of sunflower, especially if you're saving seeds from multiple types of plants. In conclusion, harvesting sunflower seeds for planting next year is a process that requires careful timing, thorough drying, and proper storage.

But with a little patience and attention to detail, you'll be rewarded with the joy of seeing new sunflower sprouts emerge from the ground next spring.



a big yellow sunflower with sunflower seeds

When to Harvest Sunflower Seeds for Birds

Birds, especially species like finches, chickadees, and cardinals, love sunflower seeds. As a matter of fact, sunflower seeds are one of the most popular seeds in bird feeders due to their high oil content and nutritional value.

If you'd like to provide some sunflower seeds for your feathered friends, you don't have to wait quite as long to harvest as you would if you were saving the seeds for planting or for human consumption.

Birds aren't as picky about the maturity of the seeds as we are. As soon as the flower's petals have started to wither and fall off and the seeds appear plump and full, you can begin harvesting sunflower seeds for birds.

However, if you want to provide the best nutrition for your feathered friends, allowing the seeds to fully mature is advisable. Fully mature sunflower seeds will have hard, striped shells and a high oil content, providing excellent nutritional value for birds.

There's also another approach. Rather than collecting sunflower seeds to feed birds, you might choose to leave some sunflower heads in your garden as natural bird feeders.

Birds will happily perch on the large heads and peck out the seeds. This approach requires minimal effort on your part and provides a source of food for birds into the autumn months.

If you opt for this method, you'll enjoy watching your garden become a hub of bird activity. After harvesting, if you're not going to offer the seeds to the birds right away, ensure they are thoroughly dry before storing them.

This prevents mold and keeps the seeds fresh. You can spread them out in a cool, dry place and allow them to dry for a few days.

When it's time to feed the birds, you can mix sunflower seeds into a birdseed mix or offer them alone. Either way, your backyard birds will appreciate the feast! In summary, whether you harvest a little earlier or leave the seeds to fully mature, sunflower seeds are a great way to provide nourishment for a variety of bird species.

Your garden will not only be beautiful with sunflowers, but it will also be a haven for local wildlife.

a close up look at sunflower seeds after harvest

Can You Harvest Sunflower Seeds from Cut Flowers?

While most gardeners tend to think of harvesting sunflower seeds directly from the plant in the garden, it's indeed possible to harvest seeds from cut sunflowers. In fact, cut sunflowers can continue to ripen and develop their seeds after being removed from the plant, provided they have been cut at the right stage and are cared for properly.

The key is to cut the sunflower at a point where the seeds have formed and are nearing maturity but are not yet fully mature. If the sunflower head is cut too early, the seeds won't have enough time to develop.

If the flower is cut too late, the seeds may already have been dispersed or consumed by birds or other wildlife. Ideally, you want to cut the sunflower head when the petals are starting to wilt, but the back of the sunflower head is still mostly green.

At this stage, the seeds should be well-formed, plump, and covered in a white or greyish husk.

After cutting, place the sunflower head in a warm, well-ventilated area out of direct sunlight. This will allow the flower head to continue drying and the seeds to fully mature.

Ensure the flower head is positioned so that it receives good air circulation, which helps prevent mold or mildew. During this period, the back of the flower head will slowly turn from green to brown, indicating that the seeds are maturing.

The process may take a week or two, depending on the specific conditions.

Once the back of the flower head has turned brown and the seeds have black and white stripes, they are ready to be harvested. The seeds should be plump and firm to the touch.

To harvest the seeds, you can gently rub your hand over the face of the sunflower, and the seeds should readily fall out. In conclusion, harvesting sunflower seeds from cut flowers is a practice that requires a bit of attention to timing and care after cutting.

Still, it can allow you to enjoy the beauty of a sunflower bouquet while also reaping a bounty of sunflower seeds.


Equip your urban green space with my recommend top tier tools.


a field of sunflowers for harvesting seeds

Harvesting Sunflower Seeds for Eating

Sunflower seeds are a nutritious snack, packed with healthy fats, protein, fiber, and a variety of vitamins and minerals. If you're planning to harvest sunflower seeds for eating, it's essential that the seeds are fully mature and properly prepared.

As I've mentioned previously, sunflower seeds are ready to harvest when the back of the flower head turns from green to brown, the petals have wilted and fallen off, and the seeds themselves appear plump and firm. The seeds should have a hard shell with black and white stripes.

Once the sunflower head has reached this stage, it's time to harvest. You can cut the head from the plant, leaving about a foot of stem attached. This makes it easier to handle. Brush off any loose petals or leaves, and then rub your hand over the seeds.

They should fall out easily. After you've harvested the seeds, they need to be dried before you can eat them.

In order to dry sunflower seeds, spread the seeds out on a flat, dry surface in a warm, well-ventilated area. Leave them to dry for a few days. Make sure to turn the seeds occasionally so they dry evenly.

Once you have dried sunflower seeds, they're ready to be prepared for eating. There are several ways to prepare sunflower seeds, but one common method is to soak and roast them.

roasted Sunflower Seed Recipe:

  1. Soak the sunflower seeds in a solution of 1/4 to 1/2 cup of salt per quart of water. Leave them to soak overnight.

  2. Drain the seeds and spread them out on a baking sheet.

  3. Roast the seeds in the oven at 300 degrees Fahrenheit (150 degrees Celsius) for 30 to 40 minutes, or until they are golden brown. Stir occasionally to ensure even roasting.

  4. Let the seeds cool before eating. They can be eaten as is, or you can crack the shell to get to the seed inside.

Remember, store any uneaten seeds in an airtight container in a cool, dry place to keep them fresh. In summary, harvesting sunflower seeds for eating involves careful timing to ensure the seeds are fully mature, along with proper drying and preparation.

But the effort is well worth it when you're enjoying your own homegrown, roasted sunflower seeds!

a big sunflower with seeds ripening

Can You Harvest Sunflower Seeds Too Early?

As with many plants, timing is crucial when it comes to harvesting sunflower seeds. Harvesting sunflowers too early can lead to seeds that are underdeveloped and lacking in the full nutritional value that mature sunflower seeds possess.

Underdeveloped seeds also may not germinate if you plan to use them for planting the next season. A sunflower seed is considered mature when the back of the flower head changes from green to a yellow or brown color, and the seeds have a hard, striped shell.

This typically occurs late in the summer or in early fall, depending on when you planted the seeds and the specific variety of sunflower.

If you harvest sunflowers before they reach this stage, you may end up with seeds that are small, soft, and pale in color, rather than the plump, firm, and striped seeds that indicate maturity. These immature seeds will be lower in oil content, which reduces their nutritional value if you're planning to eat them or feed them to birds.

If the seeds are too immature, they may not be viable for planting. Seeds that are harvested too early often have a lower germination rate, meaning fewer of them will sprout and grow into new plants.

If you're saving seeds for planting, it's best to wait until the seeds are fully mature before harvesting.

There is, however, a flip side to this. Waiting too long to harvest sunflower seeds can also present problems. If the seeds are left on the flower head too long, they may be eaten by birds or other wildlife, or they could fall from the flower and be lost.

In conclusion, while it is possible to harvest sunflower seeds too early, doing so can lead to less than optimal results. A careful balance is needed to ensure that the seeds are given enough time to fully mature, but are harvested before they're lost to wildlife or natural dispersion.

Observing your sunflowers and knowing the signs of seed maturity can help you achieve this balance and enjoy a successful harvest.

a single sunflower with yellow petals

How to Harvest Sunflower Seeds

The process of harvesting sunflower seeds is simple but requires some care.

Step 1: Check for signs of maturity

As stated previously, the first step is to ensure the sunflower seeds are ready for harvest.

The back of the flower head should be brown, and the seeds should look plump and have black-and-white striped shells.

Additionally, the petals will likely have browned and fallen off.

Step 2: Cut the sunflower head

Once the sunflower seeds are ready to be harvested, you can cut the head off the plant.

Leave about a foot of stem attached to make handling easier.

Use sharp, clean pruning shears or a sharp knife to do this.

Step 3: Remove the seeds

After cutting off the sunflower head, the next step is to remove the seeds.

You can do this by rubbing your hand over the face of the sunflower.

The seeds should fall out easily.

You can also use a spoon or another utensil to help loosen the seeds.

Step 4: Dry the seeds

Once you have collected all the seeds, spread them out on a flat surface in a warm, dry place.

Make sure the seeds are not touching each other, which helps prevent mold.

Leave them to dry for a few days, turning occasionally to ensure they dry evenly.

Whether you're harvesting sunflower seeds for eating, planting, or bird feeding, the process is relatively straightforward.

However, it does require a bit of patience and timing to ensure the seeds are mature and dried properly. But with a bit of practice, you can enjoy the benefits of your own sunflower seed harvest.

a big pile of sunflower seeds after harvest

How to Store Sunflower Seeds

Properly storing sunflower seeds is crucial to maintaining their freshness and nutritional quality, as well as ensuring they are safe to eat or viable for planting.

Here's how you can do it:

Step 1: Clean the seeds

Clean off any leftover flower material from the seeds.

If you're storing them for eating, you might also want to remove the hulls, though this is not necessary.

Step 2: Choose the right container

Store your sunflower seeds in an airtight container.

This could be a sealable plastic bag, a jar with a tight-fitting lid, or a vacuum-sealed container.

The goal is to prevent air and moisture from getting to the seeds, as this can cause them to spoil or become less viable for planting.

Here are my favorite airtight containers for storing sunflower seeds:

Step 4: Store in a cool, dark place

The best place to store sunflower seeds is in a cool, dark, dry place.

The pantry or a cellar are good options.

Avoid places with high humidity or temperature fluctuations, such as the refrigerator or near the stove, as these conditions can cause the seeds to spoil or lose viability.

If you're storing the seeds for eating, they will typically stay fresh for a few months. If you notice any signs of mold or a rancid smell, discard the seeds. If you're storing the seeds for planting, they can usually be stored for up to a year, although this can vary.

To check if seeds are still viable for planting, you can perform a germination test by planting a few seeds and seeing if they sprout.

By properly drying and storing your sunflower seeds, you can enjoy their nutritious benefits long after the sunflower season has ended, or you can look forward to growing a new crop of sunflowers when the next planting season arrives.

a bee on a sunflower

Harvesting and storing sunflower seeds can be a rewarding and enjoyable part of your gardening activities. From observing the signs of seed maturity, carefully harvesting the seeds, to drying and storing them, each step of the process carries its unique charm.

Whether you are growing sunflowers for their ornamental beauty, for a nutritious addition to your meals, or to attract birds to your garden, understanding how and when to harvest sunflower seeds maximizes the benefits you reap from these incredible plants.

Remember, patience is a virtue in the gardening world. As you watch the sunflower heads mature and the seeds develop, you're not only growing a plant but also nurturing an appreciation for the amazing cycle of nature.

Harvesting sunflower seeds, whether from the vegetable garden or from cut flowers, gives you a tangible connection to this cycle. And when it comes to enjoying the fruits (or seeds) of your labor, there are few things more satisfying than the crunch of homegrown, freshly roasted sunflower seeds.

So, next time you gaze at a field of sunflowers or admire a bouquet of these sunny blossoms, remember there’s potential harvest waiting in each of those broad, cheerful faces. The cycle of life, from seed to flower and back to seed again, is waiting in your hands.