On Mon, 19 Sep 2016 12:35:59 -0700, Oren wrote:

On Sun, 18 Sep 2016 20:34:56 -0400, wrote:

A chain saw. The grass will never thrive under the pine

Um, the lawn turf is not directly under the pine tree.

OP posted a drawing that shows a distance between the tree and the
turf.

Cite:

"...Here's a rough sketch of the area
http://i63.tinypic.com/2enuomq.gif "

IMHO the cherry tree roots "could" be sucking moisture from the lawn
turf -- root prune the cherry tree if that is in fact an issue.
I had a cherrie tree, a few spruce, a few cedat an apple and a
flowering quince. No grass under the cedars or the spruce - With the
spruce, no grass for over 3 or 4 feet beyond the circumference of the
tree.
No problem around the apple or cherry (but I took out the cherry last
year )
I've raked out the needles, limed the heck out of it, and tried
EVERYTHING to get grass around bottom of the one spruce and cedar - I
planted Perriwinkle under the othe spruce and cedars in the corner of
the lot.