I can't find the thread or forum ,but someone suggested that a way to judge how much light for a plant is to stick a solar light there.
Read the info that comes with the light…..it will tell how many hours of sun is needed to charge the light. Many are around 6 hours to 8 hours.

Honestly I have tried solar lights many times to light my walkways and things!
I wish I had all of that money back in my pocket.
None of them were any good at all.

Solar lights for walkway and stuff are not nearly strong enough to grow plants under.




I have two tube and three tube fixtures. I think the tubes are 5,000 lumens, 6,500 kelvin and on either 10, 12 or 14 hours a day.



But your question was confusing to me. Perhaps I have helped you enough for you to post your question more clearly.

The solar lights are just to test the area as to how much light there is for plants. If a solar light charges in six hours then that area is probably good for planting.

But you really do not need lights to tell you that.
Just spend one day at home, with the sun out and determine how much sun is there. It does not have to be precise. No sun, some sun, 8 hours or more is good enough.

The amount of sun on any area changes as the seasons change.
I have one spot that is full sun for many hours at the solstice,but now a month later …it is shaded more as the sun moves south.
I have a delphinium there now, but delphiniums take more shade than peonies. Another way of determining the amount of light for a given area over the whole season would be to try planting other types of plants that like full sun.
Other ways to deal with the part shade areas would be to choose peonies according to their bloom dates. In that spot (near the delphinium) an early flowering one might do ok ,but a later blooming one won't. I am thinking they need maximum sun for flowering but less to grow storage roots after. Ideally they need full sun for the whole summer.