How much sun does it take to grow a crop? Visually, about this much.
In the first week of June, 2019, my inaugural planting of sunflower seeds had their first leaves pushing up. A month later--admittedly late--Phil Sakimoto (with his dog Sundog in tow) pulled off the tape covering the pinhole of a solargraph can to launch a two-month look at the growing season.
As the crop of sunflowers grew, they topped the height of the solargraph can. At one point a giant flower covered it like an awning. I left it there for awhile before interrupting its growth since it was interrupting my solargraph.
By early September the sunflowers had grown, bloomed, and started dying back to become bird food. September 10 I ended the experiment to see how much sun a crop receives.
Shown under the bluish solargraph image is a panorama image taken with a cell phone. The pan mode distorts the image just as the solargraph distorts the image. Phil and Sundog appear on the far right.
The shifting location of the sunrise is evident on the left, while the sun appears to converge on the west horizon. This suggests the pinhole was aimed slightly east of south. Had the hole been aimed due south the solar arc would appear symmetrical.