This was a good attempt, however, it would be better if the roots could be sharper or more defined in some way. The sign seems lost in the grass. Keep trying.
Clever title!! However, the lighting is so flat it makes it difficult to make out the letter. Maybe increasing the contrast would help (if unable to wait or come back when the light was different.)
Good imagination. You can almost get pi out of that. This is an interesting image, but one of the many in this challenge that don't seem to be "well photographed". I'm affraid many images in this challenge were created with the "letter" in mind and everyone tossed out the window everything they had learned about photography. Although you have captured a "letter" in nature, I'm sorry, but I find this photo uninteresting to look at. <5>
I think this photo could benefit from more contrast, although it meets the challenge the subject is not interesting enough in my opinion to hold the viewers attention.