Spreading lawn soil or garden mixes changes finished ground levels, so establish the height against adjoining paths before adding material. Keep tree root flares exposed and leave drainage openings at the base of walls clear. Compare soil products using their stated composition and application guidance, including any allowance for settling, rather than assuming each mix will compact by the same amount.

Soil preparation for gardens and lawns

Working clay soil while wet can smear and compact it, making preparation harder once it dries. Garden mixes added above it will not fix persistent ponding caused by the ground underneath. Across Australia, soils can vary within a single site, so use a soil test to guide amendments rather than relying on a regional assumption. Check pH before adding lime or other treatments, particularly where a bed will contain plants with specific pH requirements.

How much soil is needed to fill a bed?

Multiply the area in square metres by the depth in metres to calculate cubic metres. A 10 m² bed filled to a depth of 100 mm needs 1 m³, before any allowance for settling.

Will gypsum improve heavy ground?

Gypsum can improve the structure of some sodic clays, but heaviness alone is not a reason to apply it. Arrange a soil test to establish whether it is needed and at what rate.

What depth should lawn topdressing be?

Keep the layer thin enough for grass blades to remain exposed, following the product’s application guidance. Fill deeper hollows in stages rather than burying the existing turf.