Hello mjmontana. Ken here in the Chicago area. Sorry to hear about your stone pine.
The yellowing and browning of the needles is the result of too much moisture. Basically,
the lawn wants water on a regular basis and the tree does not. You have two plants at
opposite ends of the water spectrum. If you take care of one, the other suffers.
The Italian Stone Pine is well adapted to your area and is very drought tolerant. If it is
not too large, I would transplant it to an area that doesnÃ¢â‚¬â„¢t get regular water and has
well drained soil. When you do water, which you can do occasionally, water out at the
drip line (the ends of the branches). That is where the roots are which take up water and
nutrients. Also, most pines donÃ¢â‚¬â„¢t need any fertilizer. I hope this helps. Take care.
Ken here with The Home Depot in the Chicago area