A wise man said to me today, "Its like magic." You put one in the ground and it pushes out a multitude of seeds. Oh yeah & flowers, fruits and vegetables too. So if you can't find any viable (seeds WITH life in them) head to your local library. Most like our Mountain View library pictured here will have a 'Seed' section.
Our library provides free seeds. Just sign them out and make sure to return harvested seeds for neighbors next year and they shall do the same.
Another option. Buy some seeds from your local store many types sell seeds or online provider.
Want to see before you buy?
Did you know 99% of the seed companies will send you free catalogs? Oh my what a treat you will be discovering.
That's just the beginning... And there no end. Enjoy!