The current owner (David Theodoropoulos - author of INVASION BIOLOGY: Critique of a Pseudoscience) has been there for 39 years ever since he 'dropped out & returned to the earth'. He is a strong opponent of the USDA's 'white-listing' of species, and has been extremely vocal about it.
That is good, JL Husdon says: "ALL TYPES OF SEED, including tree and shrub seed and corn seed in small packets may now be shipped directly to Canada without import permit, phytosanitary certificate or delay. A few types such as wheat (Triticum) are prohibited."
I've lived with caragana since I was a kid. The seeds don't taste very good, but the blossoms sure do! We kids used to strip them and eat them all the time, they are sweet like honey. I love this plant. It does need a good cold winter, so that may be why people on the west coast have less success with this one. Maybe plant it in the coldest spot you can find and hope. It's been my experience that deer (we have both mule and whitetail here) do not bother it at all. Rabbits, squirrels, etc, seem to eat it. I've always just dug some up from somebody else's yard, then it spreads all by itself. Doesn't even seem to matter what time of year you dig it out. I am going to try some cuttings this year and see how it goes. I don't think I could every have too much caragana. It's far prettier than lilac, too, and useful. It does produce a LOT of pods, about the size of sweet pea pods, so I think if the chickens like it, you could pick it and store easily. 36% protein is nothing to pass up, IMO. I wonder if you could sprout it before feeding to increase nutrition.