It's time to vote on our 2017 photo contest! Vote for your favorite photos of the year here!

Black Oil Sunflower Seeds Allellopathic? Will they compost?

Buffalo Grove, IL

Hi. We feed birds in feeders and on the ground-- black oil sunflower seeds. Now I discover they are toxic to some kinds of perennials. My husband has been shoveling the husks along with snow onto my newly dug, soon to be flower garden. I plan to plant a flower garden this spring. I dug it, added lots of compost, mulch and prepared it in the fall. The hulls are scattered throughout and are now covering my garden. Any thoughts? Should I be worried? I can rake off the top. Any help would be appreciated. Hope you can ease my mind. Thanks.

Anne Arundel,, MD(Zone 7b)

I have heard that from a friend but don't have a source to back it up. also cannot guess how many would have to be there to take effect.

Buffalo Grove, IL

Thanks for your comment sallyg. We decided to rake and clear out as much as we could anyway before our most recent snow and switch to a hull-less seed. From what I've read, it takes a long time to compost black oil sunflower seed hulls unless you have a very active system going and to try to compost in place it could take a very long time and damage lots of plants in the interim.

Anne Arundel,, MD(Zone 7b)

You're welcome, and thanks for letting us know what you learned.

Thousand Oaks, CA(Zone 10a)

Oh rats! I just put sun flower seed shells in my compost. Always a dollar short and a day late! Will not put anymore in. I usually sweep them up off the patio and toss them in trash. This time I tossed in compost. Not again!

Kalispell, MT(Zone 4b)

I have them all over my garden and other than their weed like growth I have never seen any reduction in growth or death to any plant they are near. Under my feeder are several inches of seed in the spring (if the snow is deep) because my chickens "clean" them all up. This chicken addition has though cleaned my 2 acre garden of many seed weeds.

Glenwood Springs, CO(Zone 5b)


Growing up in California my mom raised LOTS of parakeets & Cockatiels. A fair amount of live seed would make it out of the cages with millet & sunflower sprouts all over the place. I didn't notice an alleophitec effect like what you would see from corn glutten.

In fact, I let one sunflower grow and threw the "drippy" hose down next to it...good lord have mercy! This sunflower grew 13 feet high with a 30 inch flower. All that good seed husk mulch & bird guano. LOL

The neighbors didn't like the sunflower, because it looked at them in the morning when they picked up their newspaper. A little shop of horrors to them I suppose. ;)

The birds of Fall loved it though! I saw birds that I never saw before in 30 some odd years.


Post a Reply to this Thread

Please or sign up to post.