Trevor, when I did a search on google, i found tabs for harmonica for this song, but not guitar, which I am guessing is what you meant?

There were a couple of other sites that looked as though they would have them. I just used "whispering grass tabs" and hit search.

I did find this, too, which may be helpful: Sandy Denny Links and Mailing Lists. Looks like a good place to start.

Good luck,

kat