Sowing rates and seasons
The difference in rates is not a typo. Couch seed is so small that a kilogram contains millions of seeds, while ryegrass and fescue seeds are many times heavier. Rates are set by seeds per square metre, not by weight, which is why a fescue lawn needs four or five times the kilograms of a couch lawn.
Soft-leaf buffalo, the most popular lawn in much of Australia, is not grown from seed. It is sold as turf rolls or slabs and grown on turf farms from runners. For a buffalo lawn, use the turf calculator.
Soil temperature decides success
Seed sown into soil that is too cold sits there, and weeds win the race. Warm-season grasses (couch, kikuyu, zoysia) need soil that stays above about 18 °C, which in southern Australia means from late spring. Cool-season grasses (ryegrass, fescue) germinate best in soil of roughly 10–20 °C, so autumn is the prime time, with spring second best. In most of New Zealand, where ryegrass and fescue lawns are the norm, that means March–May or September–October. A cheap soil thermometer pushed 5 cm deep in the morning takes the guesswork out of it.
How to sow for an even lawn
- Prepare a fine seedbed. Seed needs good soil contact: rake the underlay or topsoil to a fine, level tilth with no clods. The topsoil calculator works out the underlay.
- Split the seed in two. Sow half walking up and down, and the other half walking across. That removes the stripes that single passes leave.
- Cover lightly. Rake gently so most seed is just covered, then roll or tamp the surface. Seed buried deep does not come up.
- Keep the surface moist. Light watering two or three times a day until the seedlings are up, then less often and deeper so the roots follow the water down.
- First mow. Once the new grass is a few centimetres taller than your normal mowing height, take only the top third off with a sharp blade.
Sowing extra "to be safe" backfires. Over-thick seedlings compete for light and water, stay weak and are prone to damping-off. Sow at the rate, and repair gaps with a second light sowing.
Worked examples
- New couch lawn, 12 m × 6 m: 72 m² × 10 g = 720 g, so buy a 1 kg pack. At $40 per kg the seed costs under $30.
- Overseeding a thin 80 m² tall fescue lawn in autumn: half of 40 g/m² is 20 g/m², and 80 × 20 g = 1.6 kg. Mow short, rake out thatch, sow, and top-dress lightly; the lawn top dressing calculator works out the mix.
- Patch repair: use the full new-lawn rate on the bare patch only. Measure the patch, not the whole lawn.
Grass seed questions
How much grass seed do I need per square metre?
About 10 g/m² for couch or kikuyu, 5–10 g/m² for zoysia, and 30–50 g/m² for perennial ryegrass or tall fescue. Overseeding takes roughly half those rates.
How long does lawn seed take to germinate?
In warm soil, couch shows in about 10–14 days and establishes in 6–8 weeks. Ryegrass is quicker; tall fescue is slower, and in cold soil it can take four weeks or more. Keeping the surface moist matters more than anything else.
Can I grow buffalo grass from seed?
Not the soft-leaf buffalo varieties sold in Australia. They are grown from runners on turf farms and sold as rolls or slabs. Buffalo lawns are laid as turf or planted as runners and plugs.
Is it better to sow seed or lay turf?
Seed is far cheaper, usually well under $1 per m², but it only works in the right season and takes weeks to be usable. Turf costs roughly $7–$20 per m² and gives an instant lawn. See turf vs seed for the full comparison.
Sources and method
- Sowing rates for couch, kikuyu, zoysia, ryegrass and fescue: Great Aussie Lawns – how to calculate your sowing rate and warm-season grass seed guide (couch 1 kg per 100 m² in soil above 18 °C; zoysia 0.5–1 kg per 100 m²).
- New Zealand lawn blends (25–40 g/m², soil 10–20 °C): New Zealand seed suppliers' published seeding rates, e.g. The Plant Company – lawn seeding rates. Tall fescue and soil above 12 °C: DairyNZ – tall fescue.
- Buffalo propagation: Australian turf growers, e.g. Daleys Turf – growing Sir Walter grass seed.
- Seed quantity = area × rate; pack counts round up; prices are illustrative.
Written by DueRiva · Last reviewed 23 September 2026 · Report an error