have you thought about
http://shadowcalculator.eu/
don’t let the .eu fool you. It works world wide.
in this topic i explain how to use it with some simple screenshots.
in your case i would draw a shape on the satelite image on the website where the nearest/highest tree’s are. And adjust the date/time and shape Hight to what you observed in real life. (how far the shadow got)
than you know the tree Hight. And you can just adjust the date to June or anything you want and slide the clock timer to see how the shade will fall.
might sound complicated now. but follow my links and screenshots and you’ll see it’s quite easy