All plants have preferred growing conditions, so when designing your garden try to match plants with the conditions found in each area, watching for the way the light moves during the day.
Is it shady or sunny? Sheltered or exposed? What’s the soil like—chalky or sandy, acid or alkaline? Poorly drained, well-drained or somewhere in between? All of this makes a difference to plants!
If you’re unsure, ask for help at your local garden centre. You can buy soil testing kits, and even take in pictures of your garden.