Every spring I toss in clover, kale, spinach, and now I will add oregano seeds. I already have the clover and have tossed some in under the first snow and freeze. I like to do that because they fall into the cracks as it thaws before the chickens can eat them. The other seeds need a little nicer weather to take hold.
That's what I was thinking but, never having done it before it's better to ask! I think I'm going to throw a few seeds out myself.