I'm planning a paw paw centered guild, and I wanted to use lupine as one of the nitrogen fixers. Unfortunately, I am having trouble finding a source for lupine inoculant. I have found one vendor, http://store.windcrestorganics.com/, but they only sell it in pretty large quantities: enough for a pound of lupine seed, and it costs $46.75. Anyone know where I can get some for a more reasonable price?
If I can't find a source, I'll still plant them, then dig up a couple to see if there are nodules. Hopefully, the necessary bacteria are present in the soil, but I'd prefer to inoculate to make sure ahead of time. I planted the same area with Peaceful Valley Farm Supply's soil builder mix, and used their inoculant. but none of theirs mention lupine.
Conveniently, the specific bacteria associated with lupine is named Rhizobium lupini. I googled around for cheaper source, and like you, didn't find much.
I'd second the idea of finding some native lupin in your area, although instead of interplanting, you could just remove a small amount of topsoil around the plants, and incorporate that into the soil you will be seeding into. You should get plenty of the rhizobia that way.
I know that it exists, but it seems very few carry it. Lupine is grown commercially, so the large packs are probably easier to find than the home gardener size. Here is the product you need, but in a smaller pkg):
I found this site its still only $40 bucks a pound, save 7 dollars! woohoo. But if there are any in your area already it is really easy to wild harvest. The stocks, as you know, has a bunch of flowers going up. When the flowers die, starting at the bottom, a seed pod will form, simply go out and collect the seeds