Over the past week I've been reading about Comfrey and it's supposed to be a
fantastic organic fertilizer.

Yesterday I went out looking for it growing in the wild and transplanted
eight sections of root onto a piece of scrub land closer to my garden.
Apparently it spreads like wildfire, and is very difficult to eradicate
(hence the planting on scrub land) but the plant sucks nutrients from as far
as 6 feet below the surface and stores them in it's leaves.

Has anyone else had any experience of this plant in their garden?