Originally Posted by kay

Since nobody in urg has offered you any, you'll have to travel to the W of england where it is abundant, and pick your own.

There's an annual mistletoe fair at Tenbury Wells, so english mistletoe is getting in to the market. Try googling for that, and see if it gives you any clue as to how to buy. You've plenty of time - RHS reckons spring is the best time to plant.