In the Butterfly Garden: Time to Harvest Sunflower Seeds, Here’s How to Do it

Those fabulous sunflowers you planted in the spring are likely hanging their heads by now.  The Asteracae family, which boasts more than 1,600 genera and 23,000 different species, lets you know when seeds are ready by dropping its head and turning brown on its backside. I prefer the nonnative Mammoth Sunflower for my butterfly garden.

Monarch butterfly on Mammoth Sunflower
Mammoth Sunflower seed head provides dozens of nectaring possibilities for a Monarch butterfly. Photo by Monika Maeckle

What’s so great about these easy-to-grow stunners is their amazing generosity.  Depending on the species you choose,  one tiny seed begets hundreds of tiny florets on the head, or capitulum, of the plant.  Yes, that’s correct.  EACH of those fluffy yellow growths that appear on the flower above are individual flowers.
For butterflies, this represents a nectar cafeteria.  They can land in one spot and conveniently slurp on serial nectar straws without even changing position.  But wait, this flower just keeps on giving.  Each flower later turns into a seed that birds and people seek and crave.

Sunflower head
Mammoth Sunflower head florets turn into seeds. Birds–and people–love them as snacks. Photo by Nicolas Rivard

I like to start Mammoth Sunflower seeds inside in January and transplant them to the butterfly garden in March.  By May, the stalky giants can reach 12 feet tall, their broad, foot-wide faces perching in the front yard like soldiers offering a welcome salute.  They lose their perky dispositions in June, as their heads drop and seeds form in place of the flowers.  All this for a $1.29 a pack and a regular drink of water.

Dried sunflower head ready for harvest.
Dried sunflower head ready for harvest. Photo by Nicolas Rivard

If their massive heads, ample flowers and prodigious seeds don’t convince you of their worth, how about heliotropism?  Sunflowers exhibit the endearing botanical trait of tracking the sun.  Their happy flowers faces literally turn toward the sun as it moves across the sky.  They drop their heads at the end of the day as the sun sets, and aptly, at the end of their life.

Scrape sunflower seeds from the flower head with a spoon. Photos by Nicolas Rivard

Once the flowers go to seed, you can leave them in place on the hung heads and birds will perch on the stalks and help themselves.  As the seeds dry, they disburse to the ground, where fowl, squirrels and other critter friends gather them for a handy protein pop.  One tablespoon of sunflower seeds has 4.5 grams of protein.
It’s also fun to harvest the seeds yourself for your own trail mix, to fill your bird feeder, or to plant next year.   Seven Mammoth Sunflowers I planted in my front yard this spring yielded 1.25 pounds of seed.

Common sunflowers on the San Antonio Mission Reach were prolific this year. Photo by Robert Rivard

The Mammoth Sunflower is the state flower of Kansas, but Texas has its own wonderful natives.  The Common Sunflower, Helianthus annus, may be the most common and provides prime habitat for dove and quail.   Their gangly growth habit often doesn’t fit into our home garden landscape plans, but the San Antonio Mission Reach has given the hardy, brown-centered bloomer a worthy showcase this year with well-timed rains.  Birds and butterflies have noticed and abound.   Also present: Maximilian Sunflower, Helianthus maximilianis, which has a more vertical growth habit and yellow centers.

Here’s how to harvest sunflower seeds:

1.  Wait for the heads to drop, all the sunflower petals have fallen off,  and the backside of the sunflower has turned yellow or even brown.
2. Cut about a foot of stalk off the top.
3. Scrape the seeds out with a spoon or butter knife, as shown in the video above, OR if you’re more patient,
Put a net or brown paper bag over the flower head and wait for the seeds to drop on their own.
4.  Air dry for future use.

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33 Responses

  1. Carl G Morgan
    | Reply

    I found some forgotten seed heads that had been in a hot storage shed for a few years. I planted them in March 2019. The survivors must have been the super heroes of the group. I had about 5% germination, they all went to 8′ or more (12′ on several). It looks like the years in a hot shed, in the desert allowed only the fittest to survive. Now I have so many to plant next year I am considering growing a jungle of sunflowers in the fall.

  2. Larry Mullenax
    | Reply

    Hello from Iowa , I’ve planted mammoth sunflower seeds they are anywhere from 12 to 14 ft tall Quite A Conversation Piece I must say , probably Harvest them this weekend or next weekend but they are bent over quite a bit now , it has been a dry hot year , so I did fertilized and watered quite a bit this year , turned out very nice. thanks

    • melissa Collins
      | Reply

      I live in Ohio and I planted a row of Mammoth Sunflowers in May. Almost all the flowers are hanging now but most still have the tiny yellow petals, although dried up. Is it best to cut them now or let nature do her part? I will never go a summer again without my sunflowers my family adored them!

      • Allison
        | Reply

        I too am wondering, do you let them dry on the stalk or can I cut it and bag it and leave it to dry in the garage?

  3. Chasity
    | Reply

    I cut my head off too early. If I hang it out to dry do the seeds still have a chance? The seeds are there. The heads are drooping and the flower leaves are fallen off..

  4. […] Dry for use at a later date.  Find out more… […]

  5. Cindy
    | Reply

    Hi, Last year was my first time planting Sunflowers (Mammoth). From the seven seeds I planted only 3 survived. They were beautiful! I harvested the seeds from the flower head and put several seeds in envelopes which I planted the following spring. I got a great amount of them to come up. I gave some to my neighbors and they had great results also! So you can bet I’m planting them again next year.
    This year I also found some with just WHITE seeds. Are they any good to use or did I pick the sunflower to soon and didn’t give it (the seed) time to fully develope?

  6. […] Dry for use at a later date.  Find out more… […]

  7. sharon Mcglothin
    | Reply

    First time grow sun flowers. I just planted my seeds in my garden with my other flowers. I ended up having five big mammoth sun flowers my first one got so big that it leaned and broke off so if finished cutting it and put it in a brown paper bag in my house upside down with twine and a hanger (the back was already Yellow and all the petals were gone) that’s been about a week ago Its slowly drying but my seeds are white… Did I cut it down to soon?

  8. […] […]

  9. Steve Utting
    | Reply

    First time growing sunflowers, tallest is nearly 12ft not bad for London, I know what to do with the heads and seeds but is it best to pull the stems up including the roots ?

  10. Bill Clarke
    | Reply

    Planted a package of sunflower seeds in my garden.Holy crap only one came up,but it was huge.we live in Kamloops BC Canada.have never seen the like of these seeds.Planted in 3rd week of May,it,s almost the end of August.Think it will be ready in the next few weeks.Can,t wait to try these,and will definitely be planting these again next year.

  11. phyllis
    | Reply

    I think I picked my sunflowers toosoon. Have lots of white seeds…no husks…what can I do to try to the point of getting husks or not?

    • Ann-Marie
      | Reply

      I’m in this boat, too. Is there an way to ripen the seeds once the flower has been cut down?

  12. robert
    | Reply

    I planted the mammoth type seeds in the spring here in Macon Mo and with the help of miracle grow and Thrive the plants reached fifteen feet with massive double heads. I may have cut them down a little early but they were getting real ungainly for the front yard. This is the first year I have planted them and received a lot of comments on how huge the plants were. I have the heads set aside to dry out.

  13. Canny
    | Reply

    Maximillian Sunflowers are perennial; plus, they self-sow like crazy! In 2011, I had ONE plant; in 2012, about 10; last year maybe 25; this year—— oh my word, they really “went to town”— there are probably 60 or 70 now on individual stalks. I didn’t intentionally sow any seeds; I guess the finches did. I’d post a photo of last year’s crop if I could! They get really tall, so I always cut mine back in August so that when they bloom in September, the stalks will only be about 5 feet high and won’t be so tall that they all just lean over.

  14. damian
    | Reply

    What happens to my giant sunflowers when head as been removed
    Do I have to plant new seeds or will they grow new heads

    • Monika Maeckle
      | Reply

      It us an annual so you will have to plant more seeds–unless some have fallen and sported as volunteers.

      • damian
        | Reply

        Thank you for reply but I’m saddened that they only flower once

  15. boomerpete
    | Reply

    this was just what i wanted to know, a local couple decided that “GRASS” WAS TO LAME for the spot between the house and driveway. so planted a ton of sunflowers. i stoped and ask if they would sell me a couple heads when they went to seed, and they said just to pick a couple when ever i wanted.
    so i plan on having flowers next year.

  16. dennis a.
    | Reply

    Thanks for this article. I have the mammoth sunflowers in our frontyard and started blooming! They are huge indeed, and very attractive.
    I was just wondering if this variety will bloom or yield again and again? Or it is just a single flower per plant? (Which would mean once the flower is harvested, the plant has no use anymore and can now be taken down?)

    • Monika Maeckle
      | Reply

      Sunflowers are annuals, so they won’t bloom again. However, don’t take them down too quick, as the birds love eating the seeds and will be drawn to your garden. Save some seeds for next year and plant for more flowers.

      • Dennis A.
        | Reply

        Thanks for the quick response, Monika.
        So mammoth sunflowers only have 1 flower during the year /lifetime? If we harvested the flower and put it in a vase inside the house, can we now then cut down (or replace) the plant at the frontyard?

  17. Monika Maeckle
    | Reply

    Why not try a seed and see if it’s ready? If it’s tiny and yields no meat, give it more time. Good luck! –Monika

  18. Richard Bent
    | Reply

    Very informative and helpful. I planted three different plants. Two of them stayed small but have excellent seeds. The one large one, has drooped for a while now. I noticed lots of ants in the plant when the small yellow flowers were present. I have pulled off a few of the seeds of the large plant but there is no kernel inside. Only my small plants have the kernels. Do I need to wait longer? The back of the plant is still green. We are still having warm daytime weather, but cool nights.
    Laguna Niguel, California

  19. Canny
    | Reply

    My Maximillian Sunflowers just began opening this past week. And to my delight, the butterflies discovered them immediately. Ha, they probably had their eyes on the ever-swelling buds all along…
    But you’ve inspired me to sow some Mammoth seeds for next spring!

    • Monika Maeckle
      | Reply

      Excellent! You won’t regret it.–MM

  20. Frances
    | Reply

    My last Mammoth Sunflower just bloomed. The flowers were really pretty this year.
    Here in South Texas, it’s August 2 (2012). Can more sunflower seeds be planted now
    to bloom in the fall?
    Thanks for your answer.

    • Monika Maeckle
      | Reply

      I think it’s too hot to grow them now and you may not have time for them to get to the flower phase before the days get short. However, consult the seed package as some may have a shorter life cycle. Good luck! MM

  21. Jim Latham
    | Reply

    Now that I have harvested my sunflower seeds, how do I store them. When and how do I oplant them for next year?

    • Monika Maeckle
      | Reply

      Jim, just store them in a dry cool place in a paper bag where they can get air. Plant next year, but depending on the species (and weather or not it’s a hybrid), it may not bloom true. Good luck. MM

  22. Monika Maeckle
    | Reply

    Thanks, Ken. Nick took most of those photos with his fancy camera. The “video” is actually a GIF file that he pieced together from the still shots on Photoshop. I’m sure he can tell you how to do it.

  23. Ken Rivard
    | Reply

    Great post, Monika! Brought back a lot of sunflower memories from childhood Michigan. Particularly lovely photos this time around. What did you use for the video of scraping the seeds out of the head?

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