I have spent all summer watching my giant sunflowers grow to amazing heights, and they have been crowned with stunning blooms, and those blooms are beginning to turn into heavy seed crops. But even though the seeds may have already formed, they are not necessarily ripe for harvesting right away, despite eager birds that may nibble at the seeds as soon as they appear.
To get the most of your sunflower seed crop, it will be necessary to protect the seeds from birds until they are ready to harvest. I wanted to share with you some more information on this great crop.
Covering the seeds is the best way to keep birds from eating them prematurely, but the cover you choose must be able to permit air circulation so the seeds can continue to ripen. A used pantyhose stocking can be stretched over the sunflower heads, or similar cheesecloth or netting can be wrapped around each flower head. Another option is to tie paper bags loosely over the blooms with twine, but avoid tying the bags so tight that air cannot freely circulate around the bloom. Plastic bags should be avoided because they will condense moisture and cause rot on the seeds, making them less appealing to the birds.
While the birds do not mind eating unripe sunflower seeds the ripe seeds have larger kernels with more nutrition for the birds. There are several clues that can help you determine when your sunflower seeds are ready to harvest: the back of the flower heads will turn pale yellow, and the edges will begin to brown; the seeds themselves, which are white at first, will darken considerably and the soft ends of the buds on each seed will dry up and fall off, exposing the full seeds.
Of course, if birds are giving your sunflowers more attention than your bird feeders, it’s probably a safe bet that your sunflower seeds are ripe for harvesting.
Harvesting the seeds is as easy as cutting off the flower heads, leaving 2 to 3 inches of stalk on each one. Once you cut the flower heads I suggest that you store the heads in a dry area such as a shed or garage until you are ready to start feeding the birds and other critters. The drier the flower heads are, the easier it will be to extract the seeds, whether you want to do it yourself or let the birds handle that task.
Many folks struggle with the idea of prying out the hundreds or thousands of seeds from each flower head in order to feed them to the birds, but there really is no need.
Birds’ bills are ideally suited for extracting their own seeds, and the easiest way to feed them your homegrown sunflower seeds is to set out one of the dried sunflower heads on a tray or platform feeder and let them enjoy it. You can also use the end of the stalk to poke through a fence or trellis to hang the sunflower heads for the birds to feed on. For the very largest sunflower heads, consider wrapping string or twine around them and hanging them, seed side up, for an impromptu hanging platform feeder. After the birds have eaten all the seeds, you can sprinkle mixed birdseed on the empty sunflower head and the small seed pockets will hold the seed securely, allowing birds to continue to use the natural feeder.
If you want to loosen the seeds before putting the flower heads out for the birds, rub your hand across the seeds in alternating circles (wearing heavy gloves will make this more comfortable). Some seeds may detach as you do this, and it is easy to save those seeds for replanting the next spring in a small, labeled envelope stored in a cool, dry place. Seeds you replant, however, may not have the exact qualities of your first crop, depending on the crossbreeding of the original seeds and any cross-pollination that took place to produce your first flowers.
With a bit of planning and some care while your sunflowers are ripening, you can easily harvest dozens of sunflower heads bulging with seeds that your backyard birds will appreciate. Carefully saving the seeds can give you a rich supply of winter bird food, and by saving just a few individual seeds for the following spring, you can be sure of another great harvest the next year and an ongoing supply of nutritious, attractive, inexpensive food for your backyard birds. I am looking forward to harvesting my sunflowers.
Dr. Lamont is a professor and extension vegetable specialist in the Department of Plant Science at Penn State University and can be reached by e-mail: firstname.lastname@example.org.