For Lisa Mercer, the richest horizons are found underground, in soil profiles that support her vision for a curated native garden.
It's one of the reasons why a tree can thrive in one backyard but remain stunted in another.
"When a developer cuts a site ready to build a home, they cut into the soil's horizons and you end up planting in soil that would never normally support plants, almost to the bedrock," the Queensland landscape architect said.
"You can't just put 200mm of topsoil on it and expect a good quality garden to grow easily, you need to make sure you are recreating a natural soil profile to support small, medium and large plantings."