Is anyone aware of a chart or something that give explicit explanations as to sunlight needs? For example, if something needs Full Sun, does that mean for a certain number of hours per day? If it only gets Full Sun for say 4 hours, will it just not thrive as well, but still probably be OK?

In my small yard for example, due to nearby buildings, etc., the sun exposure varies from one part of the yard to the next. One section gets full/direct sun from 10a-12p, and then indirect sun (which to me means no sun at all, but the sky itself is still bright) for the remainder of the day. Other parts of my yard are in indirect sun all day. Another part gets direct sun from 12:00-3:00p only. So the more I think about it, the more unsure I am as to if I should have shade plants or sun plants. Is 3 hours of full, strong sun enough for plants that require Full Sun? If not, then would I want to get Medium Light plants for the 3 hours of sun area? And what exactly is the difference between Shade and Indirect Light?

Thank you!!