Black oil sunflower seeds for planting - Ask Extension
Over several years, I've been in the habit of planting them to develop a sunflower garden. This year and maybe last year, the result was no seedlings....
Knowledgebase
Black oil sunflower seeds for planting #909082
Asked July 09, 2025, 1:55 PM EDT
Over several years, I've been in the habit of planting them to develop a sunflower garden. This year and maybe last year, the result was no seedlings. Both years, probably, but this year certainly the failure wasn't due to critters finding and eating seed.
My birdseed came from Canada for this feeding season and I wondered if the seed might have been rendered non-viable for planting for some reason. Perhaps due to a UDSA regulation for imported seed?
Thanks
Frederick County Maryland
Expert Response
Wildlife like birds, rodents, and seed-eating insects (beetles, maggots, etc.) tend to love eating sunflower seeds, so if you are certain that the seeds sown were protected from predation, then perhaps environmental conditions prevented germination or rotted the seed. It's possible that the seeds were irradiated to pass customs, but that should not affect germination since we don't think there would be a requirement to render them sterile in this case.
If you have any of that batch of seeds remaining, you can perform a germination test. (Use containers and potting mix, or just try wrapping them in a damp paper towel in a humid container and see if they sprout.) See if the seed packet has a stated germination rate (listed as a percentage, most likely), and contact the supplier directly if they are failing to sprout. Perhaps they are too old to be viable.
Unfortunately, germination failures like this aren't unheard of, though we don't always know the reason: some of our own team members have had the experience of trying to sow sunflower seeds where none of the seeds germinated (all from the same packet, across three sowing attempts in that case).
Miri
If you have any of that batch of seeds remaining, you can perform a germination test. (Use containers and potting mix, or just try wrapping them in a damp paper towel in a humid container and see if they sprout.) See if the seed packet has a stated germination rate (listed as a percentage, most likely), and contact the supplier directly if they are failing to sprout. Perhaps they are too old to be viable.
Unfortunately, germination failures like this aren't unheard of, though we don't always know the reason: some of our own team members have had the experience of trying to sow sunflower seeds where none of the seeds germinated (all from the same packet, across three sowing attempts in that case).
Miri
Maybe I need to be more specific...
The seed was from a 50# bag of black oil sunflower seed from Canada packaged specifically for bird feeding. The sowing failure was a patch of sunny soil with approximately 150 seeds planted individually in each of two attempts. Our abundant rainfall should have promoted germination, but no seedlings were ever observed. No seed predation was observed. The same situation occurred last year and tho I believe that seed also came from Canada, I can't be certain.
Possibly the USDA would have some insight. I haven't contacted them and it appears that you haven't either.
We do not have a specific contact at the USDA, but you are welcome to ask them if there regulations about importing viable sunflower seeds. We mainly reach out to the MDA when we have local regulatory questions.
Were the seeds hulled/hull-less? (Some sunflower bird seed is, as the birds seem to find that more appealing and it eliminates the litter of hulls around the feeder, but such seed tends to be more expensive. Hulling would probably interfere with germination since it's a protective seed coat.)
We do not have an explanation for why the germination failed on such a large scale if the seed is not sterile. The hulls of sunflower seeds can be somewhat allelopathic, containing chemicals that inhibit germination, but presumably that would not impact the same species, only other plants that would be competition for the seedlings. If the sown seeds were not missing (and therefore not eaten), were they also not molding or otherwise beginning to decay? If not, that might suggest something like a treatment residue may have been inhibiting germination. This would be something you'd need to ask the manufacturer, however. If they were in cold storage, froze, or were stored too hot, that also might have impacted viability, even if those storage conditions were not used specifically with the intention of affecting germination. If a germination test is successful (the paper towel in a plastic bag method), then we can of course rule out sterility and interference with chemical inhibitors.
Miri
Were the seeds hulled/hull-less? (Some sunflower bird seed is, as the birds seem to find that more appealing and it eliminates the litter of hulls around the feeder, but such seed tends to be more expensive. Hulling would probably interfere with germination since it's a protective seed coat.)
We do not have an explanation for why the germination failed on such a large scale if the seed is not sterile. The hulls of sunflower seeds can be somewhat allelopathic, containing chemicals that inhibit germination, but presumably that would not impact the same species, only other plants that would be competition for the seedlings. If the sown seeds were not missing (and therefore not eaten), were they also not molding or otherwise beginning to decay? If not, that might suggest something like a treatment residue may have been inhibiting germination. This would be something you'd need to ask the manufacturer, however. If they were in cold storage, froze, or were stored too hot, that also might have impacted viability, even if those storage conditions were not used specifically with the intention of affecting germination. If a germination test is successful (the paper towel in a plastic bag method), then we can of course rule out sterility and interference with chemical inhibitors.
Miri
