I started with a lawn and a tiny just-planted tree, south-facing. Hot, sunny, dry. Every year, it kept changing, especially due to the growth of my tree and the just planted trees to either side on the neighbours' front lawns.
So flocks that flourished for years, peonies, daisies, coreopsis, aloe, and other sun-loving plants I tried eventually died off. Also things happened, a hydro dig. The Enbridge catastrophe.
But finally, I have the balance of plantings and shade.