How to find out if a yard has full sun

May 16, 2019 8:20 AM

I'm looking for a quick way to find out how much sun a backyard gets. I've seen google's project sunroof, but I want to grow vegetables, and not on the roof! I don't have access to the backyards of interest.

So far the best I've solution I've found is the website findmyshadow.com, with which the user draws shapes to represent trees and buildings, and the website calculates where the shadows fall at user specified longitude/latitude, dates, and times. I can use a satellite view from google maps as an underlay, so I can get the positions of the shapes in about the right place, but the heights are guesswork. Not only is it inaccurate due to heights, it's also pretty time-consuming.

Is there a better way?

posted by SandiBeech to Home & Garden (7 answers total)

I'm imagining this is for houses you're thinking about buying, so do you perhaps have photos of the yards? If you can identify plants that currently grow there, it'll give you an idea of the conditions. I generally have found that only a handful of species tend to get chosen for landscaping in any given area, so this isn't as daunting a task as it might seem.
posted by teremala at 8:29 AM on May 16, 2019

More on the time-consuming option —

In Google Earth Pro [and maybe regular, too], you can see aerial imagery at several different dates. This can show various versions of how much shade the property gets.

There are often items in images that have fairly standard heights [e.g. utility pole, 34ft above ground] that you can use to calculate angle of sun and then use other shadows to calculate heights if needed. Tedious, I concede.
posted by Glomar response at 8:51 AM on May 16, 2019

What direction does it face? What is between the garden the southern exposure (N. Hemisphere) - trees, fence buildings? What zone are you in? I'm in Maine, Zone 5, and have a short growing season. The trees next door have grown so I had to move my vegetables to the front yard to get unobstructed sun. Less lawn to mow. Now, I just have to deal with greedy squirrels and a very cold Spring.
posted by theora55 at 9:14 AM on May 16, 2019

Like, how accurate do you need it to be? There's usually a few places in a yard that get sun for part of a day, sun for part of a year (due to adjacent foliage), sun in the morning, sun in the evening, etc.. Do you need this to estimate for purchasing a home or are you doing something commercially like designing people's vegetable gardens remotely?
posted by amanda at 10:28 AM on May 16, 2019

You could play around with the i-tree design website and see if that gets you an answer... It’s really for plotting out tree locations/growth and estimating home energy savings, but it might help you figure out the sun/shadow breakdowns.
posted by Maarika at 11:12 AM on May 16, 2019

I really like the "augmented reality" app called Sun Surveyor. If you check out some screenshots you can see how it superimposes the sun's path on the camera image of your phone, so you can easily tell where the obstructions will be at any given time or date. I've used it for precise hours-of-sun calculation in exact spots in my well-obstructed yard.
posted by tybstar at 11:50 AM on May 16, 2019 [3 favorites]

https://www.suncalc.org might work.
scrolling in with satellite view and playing with the sun/ecliptic should give you a sense of sunlight in the yard.
i'm hoping to use it to lay out my flagstones so that they align with sunrise on the solstice 13,000 years ago.
posted by 20 year lurk at 12:31 PM on May 16, 2019 [4 favorites]