Least amount of sun for white willow planted outside

I have trees to contend with so need to plant my white willow in a place where it gets the most sun, what’s the least amount?

Where I live, the less shade the better. It really depends where in the world you’re located but generally speaking more light is going to produce a more robust plant of any species.
Worst case scenario is it doesn’t get enough light, is dwarfed or stunted or flowers before it’s grown to the vegetative size you wish to achieve.