The dividing line between sun and shade is this - If the garden spot is sunny between the summer hours of 1:00 P.M. and 6:00 P.M., then it is considered to be on the sunny side.

At our nursery, on our pricing signs, we divide the Full Sun designation into Full Sun and Cool Sun, and Full Sun with Heat Tolerance, the latter meaning plants for the inferno patch, or hell strip.

We have also created the designation of Cool Sun for Utah. These are full sun areas that are not near any sources of radiating heat such as near concrete, or the south side of a house. These are spots that are surrounded by signficant areas of grass, or other plants. Cool Sun areas would also include full sun areas right outside the parameter of the shade line.

Part sun areas are defined as areas with morning shade but afternoon and evening sun. Part Shade areas are defined as morning sun, but afternoon shade. Many Spring flowering perennials are defined as Part Shade or Sun in Utah. They are flowering in full sun, but they are are flowering at a time, coverd by trees that have not leafed out yet, or are in the process. These plants do not like our summer heat, but they are shaded during that time frame.
