Turf is instant. Rolls go down, the section looks finished the same afternoon, and it can be walked on lightly within days. It costs more per square metre and it still needs careful watering for the first few weeks while roots knit into the new soil underneath — and on a slope it holds the surface immediately, which matters.
Hydroseed — a sprayed slurry of seed, mulch and fertiliser — costs noticeably less and covers large flat areas well, but it needs two to three weeks of consistent watering before it can be walked on at all, and on a genuinely sloped section the seed and mulch can wash before it germinates unless the grading and timing are right.
The deciding factor is usually timeline and slope, not preference. A property going on the market in six weeks needs turf. A flat, river-adjacent section with no deadline and a tighter budget is well served by hydroseed. A steep ridge-top section leans turf, for the same reason a slope needs instant surface hold.
Either way, the soil prep underneath doesn’t change. That’s where the job actually lives.