Mr. Whingnut,
I used to think this was a good idea too, I have since changed my position for some of the items already mentioned by Mr. Day.
I personally will not use any outside sources of stuff unless I personally know the person/people who are the source of material. And even then, one might get an unfortunate side effect due to importation of a disease.
One example, from my first
hugel experiment, for not importing anything/very much is horse
poop.
Great fertilizer? not if the horse owners put dewormer through the gallut of the horses every month.
I just then imported a bunch of worm killer to my garden where I want a lot of worms.
Eventually worms were in abundance, but I am sure it was slowed down and had negative consequences.
I think trees like figs, which grow crazy fast and can withstand some cold, might work depending on your climate. Alder?
Hairy Vetch, Nasturtium, clover, buckwheat, all are options I would persue b/4 taking in unknown, bulk, yard waste.
Will Allen does a lot of compost diversion in Milwaukee.
Part of me says "Cool, Nice Job" and part of me says "Not for me."
And another part says "That will likely be a problem of unforeseen consequences" and another says:
"I hope this model gets scrapped asap and folks don't through away organic matter b/c they feel it is way to valuable to their own site to truck it away."