When to Harvest Sunflowers – Gardening Tips 2024

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Big, bold, and brash, sunflowers are multi-purpose. They provide stunning flowers that brighten up any house, attract bees and other useful pollinators for your garden, and are also a source of nutritious seeds. Learn more about when sunflowers are ready to harvest and what their many uses are.

When to harvest sunflowers? There are two main reasons to harvest sunflowers and which reason will shape the harvesting process. If you want a lovely bouquet of fragrant flowers, make sure you harvest when the plant is still full of life. The stalk should be firm and upright and the leaves a healthy green. The flower head should be just slightly open. Don’t worry as the petals will unravel after you cut the flower, adding more longevity to your bouquet. If you want some delicious seeds, allow your sunflowers to grow longer. The stalks should still be upright but will be about to wilt. The leaves and back of the flower head should be brown and most of the petals should drop. Look for nice, plump seeds.

Once ready, remove the head and place it in a large container. Rub your hand over the seeds so that they drop. You can choose to eat the seeds raw, give them a good clean, or pop them in the oven for a roasted flavor. And finally, if you’re tired of all the fuss of your garden, simply leave your sunflowers alone and let nature, and the birds, take over.

How do you know when your sunflowers are ready to harvest?


Despite their grandiose size, sunflowers don’t take too long to grow and will start to bloom by the end of July. Hot weather will speed the process along and depending on your climate, you can expect sunflowers to be in full bloom between July and September.


There are many different varieties of sunflowers, so size is not a universal indicator of readiness. The mammoth variety of sunflowers will tower 12 feet tall and have headed over 10 inches wide.

Then there is the Teddy Bear variety. It camouflages its way into any garden as it grows to be just 2 to 3 feet tall with a flower head about 5 inches wide.

It’s best to check your seed packages to see what type of sunflowers you have and what the information says about size, both in height and in flower width.


For those that want to harvest their sunflowers for bouquets, you want to pay attention to the petals around the head. They should be opened slightly but not all the way.

Sunflowers will continue to open up once cut, which will give you an extra few days in a bouquet. If you wait too long, the petals will start to fall off quickly after you cut the flowers.


An alternative to cutting sunflowers for their beauty is harvesting sunflower seeds. If this is your plan, wait until the seeds look plump. Too small, and while they may be edible, it will be a lot of work for not a lot of taste.


When picking sunflowers for a bouquet, you want the plant to have plenty of life. The leaves should be green and the stalk should be nice and firm.

For seeds, however, the plant needs more time to grow. In fact, the foliage should turn brown and even the head of the flower should be brown on the backside.

What happens if you don’t harvest sunflowers?

Any home gardener who has grown sunflowers knows that the following year there will most likely be some volunteer growth in your garden. Sunflower seeds grow quite easily.

If you leave your sunflowers in your garden and don’t harvest either the flowers or the seeds, the plant will eventually fall down due to the weight of the head and the lack of nutrients in the stem.

While the stem can take quite a bit of time to compost on its own, due to its fibrous material, the seeds will quickly be picked apart by birds. As the birds eat the seeds, they will scatter some.

Other times, birds will eat the seeds and as they fly away, will naturally poop out some of the seed.

The result could be a bunch of sunflowers scattered around your garden, as well as your neighbor’s. Really, this is kind of fun and a good lesson in plant survival.

How to harvest sunflowers for bouquets

When you see your sunflowers begin to develop their flowers, it’s time to think about cutting them for a bouquet. As stated earlier, you want to find a sweet spot for harvesting the flowers.

Too early and the flower may not open on its own. Too late and the petals will drop immediately after being cut.

When the flower heads are about halfway open, this is the perfect time to harvest. If you cut it at this time, you might encourage the plant to produce side blooms for a second harvest.

It’s important to cut sunflowers in the morning. The stems need a lot of water to remain upright and they will be the fullest in the early morning.

Another important tip is to be careful with your sunflowers. The petals are quite delicate and if you jostle them too much, the petals will quickly drop.

Depending on the variety of your sunflowers, the stem can be rather cumbersome to cut through. Kitchen scissors probably won’t be tough enough. Instead, use a larger set of pruning shears for the job.

Once cut, place your sunflowers in a tall jar. The stems should be cut so that the heads can rest on the top of the vase. This way they will stay upright and won’t flop over.

Keep the water fresh and your sunflowers can last up to a week inside.

How to harvest sunflower seeds

Sunflower seeds are a tasty snack enjoyed by both people and birds. Don’t let your sunflower heads go to waste; be sure to harvest the seeds.

Sunflower seeds for birds

Birds have fewer needs with their seeds so it’s a lot easier to harvest sunflower seeds for future birdseed.

Start by leaving the seeds on your sunflower head. Wait until the seeds look plump and slightly loose. As for the sunflower plant, the leaves should turn yellow and the petals will start to die off and fall off.

Finally, take a look at the back of the sunflower head. It should turn from green to brown.

Once these signs are evident, it’s time to harvest the seeds. Take a sharp pair of pruning shears and cut the head of the plant off, making a cut about 6 inches below the head.

Place the flower head in a container to catch any seeds that naturally fall off. Then, take your hand and run it over the surface of the sunflower head.

Most of the seeds should naturally fall out at this point. An alternative is to pick up the sunflower head and rub it across a rough surface. Just be sure to do so inside the bucket to catch all the seeds that fall off.

Sunflower seeds for roasting

If you want sunflower seeds for roasting, you want to use a bit more care so they are in the best shape possible. Because sunflower seeds need to remain on the plant for a while, they are at risk of an early meal from birds.

To prevent birds from munching on your seeds, cover the head with a cheesecloth and secure it to the stem with a rubber band. This allows proper airflow and exposure to the sun to dry out.

After you collect your sunflower seeds, they are ready for consumption!

Should you wash sunflowers after harvesting?

Advice on washing sunflower seeds really varies. While the purists out there believe you can simply pluck seeds right off the flower and pop them in your mouth, others offer a cleaner alternative.

If you are worried about dirt or germs, then by all means wash your sunflower seeds first. Place them in a bowl of water and agitate the water to get any stubborn dirt off.

Then, lay the seeds on a tray and allow them to air dry. This may take some time so it’s best to leave them in a warm, dry place for a few hours.

Can you eat sunflowers immediately after harvesting?

Yes, sunflower seeds can be consumed right away. Most people are familiar with roasting them, but why not try some fresh from the plant to see if you prefer them this way.

If not, take your collected sunflower seeds and place them on a single layer on a tray. Put them in the oven for a few minutes and then sprinkle a light dusting of salt over them. Voila! A tasty, economical snack that is also nutritious.


It’s always amazing when nature provides something that is both beautiful and edible. Sunflowers can be harvested for their flowers or seeds, whichever you prefer. To add to a bouquet, wait until the flowers are half-open and for seeds, wait until the foliage is brown and the seeds are nice and plump.

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