Shade calculator?

Morning sun in our new home is obstructed with the woods on east side and woods are not removable - they surround a creek flowing in a deep ravine and removal of the trees is both prohibited by the town and dangerous for my land due to possible erosion. Today I checked when the sun comes to the one of the spots where I plan to plant my fruit trees. According to Raintree nursery you suppose to count your sun hours between end of June and beginning of August. Geometry and especially astronomy never were my strong subjects in school. Is it possible to say, where the shade of a particular tree(unknown height) will be in the middle of July at 10 AM, if I know where it was today at 10 AM? I need to figure out if my tree layout works before July… Right now I am planning to space the trees 15’ in a square (apricot, 2 Asian plums, persimmon). But if it would be too dark on one corner of the square, I may need to shrink the distance and target smaller trees . Need to decide ASAP, as trees are already ordered.
May be somebody have a link to some shade calculator that doesn’t involve tree height?

We have solved it… Actually my husband did . We measured the distance from the end of the shade to the shade tree (on the line from center of future tree to the shade tree). Fortunately that pine was on this side of the creek. Then we figured out the sun angle for today’s day and time when we measured. ( Sun Angle Calculator) When you know the angle and the leg you can calculate the other leg - height of the tree. Now we found an angle that sun will be at at 10 AM at July 12. Knowing the height of the tree we now can calculate the length of the shade at this time.
According to the calculation the full 8 hours of sun will be in dark corner from May to end of August.

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You can also find tree height without knowing the sun angle; just measure (within the same minute or so) the shadows cast by a vertically-held yardstick and by the tree; the shadow lengths and the tree and yardstick lengths will be directly proportional.

For setup to work, the slope of the ground along the shadow of the tree needs to be a small fraction of the tree height, level ground is best.

Then to predict the tree shadow at a later date, you do need to consult a table of sun angles.


have you thought about

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


I saw it, but I can’t figure out how to enter my coordinates

You can also try this website to get idea of the arc the sun will follow on any particular day. In the summer, the sun will be much higher in the sky for a longer period of time making it easy to get sunlight from above. If you’re in MA, you’re also in higher latitude which makes getting more sunlight during summer even easier. Good luck.


just put it on “map” top left corner. And use the “hand” and zoom “+” and “-” to find your house/garden

A handy tool. Also good for crops that need mixed sun/shade.

I see this question is from last spring so it might not matter to you any more, but if anyone is trying to figure out the path of the sun at any date/time from any position, Sun Surveyor is a great app to use. It superimposes the travel of the sun on your phone’s camera and you can select any date.

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Ditto. I use this all the time and have mapped out the marginal spots in my yard:

I just pick a summer day and add up the unshaded hours on that day as I stare through the screen that has the sun superimposed on the sky.

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