I love the story about the settlers growing roses in potatoes to transport them to a new location, and I agree that this was an ingenious way of supplying the rose with moisture on the trip, but I can't get excited about using potatoes as a rooting medium in the garden. It seems to me that even if you removed the potato plant growth, the potato itself would prevent, or at least complicate, the growth of the rose roots. If we're not traveling to a new location and are just staying put in our gardens, it's simple enough to keep the soil around a cutting moist without the aid of a potato.
Maybe there's some other benefit to the potato? Extra potassium, perhaps?
