Lawn mowing heights: how short to cut every Australian grass

Most Australian lawns want to be mown somewhere between 10mm and 75mm, but the right number depends entirely on grass type: couch as low as 10–25mm, kikuyu 25–40mm, zoysia 20–35mm, buffalo (including Sir Walter) 30–50mm, and cool-season tall fescue much taller again at 35–75mm. The number matters less than the rule behind it — never remove more than a third of the leaf height in one cut — because cutting too short stresses the plant and cutting too rarely lets thatch and weeds move in. Everything below covers the exact heights, why they differ, and how to set your mower to hit them.

Quick-reference mowing height chart

Ranges, not fixed numbers, because sun, shade, season and lawn stress all shift the ideal height within each range. Use the lower end in cooler months and full sun, the higher end in heat, drought or part-shade.

Grass type	Mowing height	Notes
Couch	10 – 25mm	Raise to 25–35mm over winter dormancy
Zoysia (e.g. Empire)	20 – 35mm	Slow-growing; tolerates the low end well
Kikuyu	25 – 40mm	Toward 40–50mm in heat, drought or shade
Buffalo (e.g. Sir Walter)	30 – 50mm	35–45mm the sweet spot for most lawns
Tall fescue (cool-season)	35 – 75mm	Never below ~35mm, or it dries out and thins

Why mowing height actually matters

A lawn's leaf is its solar panel — it's what feeds the roots. Mow too short and you strip away most of that leaf area at once, which does three things at the same time: it shocks the plant into spending its energy reserves on emergency leaf regrowth instead of root growth, it exposes bare soil and the crown of the plant to direct sun and heat, and it lets sunlight reach weed seeds that a taller canopy would otherwise shade out. The result is a lawn that needs more water, recovers more slowly from heat and traffic, and loses ground to bindii, clover and winter grass over time.

Mow too infrequently and you hit the opposite problem: letting grass grow long, then chopping it back hard to "catch up", removes far more than a third of the leaf in one go — scalping by a different route. Thatch also builds up faster under an irregular schedule, since fewer, heavier cuts leave more old growth sitting at the base of the plant. Height and frequency are really the same decision seen from two angles; our guide to how often to mow your lawn covers the scheduling side in more depth.

Mowing height by grass type

Buffalo (Sir Walter and other buffalo cultivars)

Keep buffalo between 30mm and 50mm, with 35–45mm suiting most home lawns. Buffalo is a runner grass that spreads via stolons across the soil surface, and cutting it too low exposes those stolons to sun and foot traffic, which is the single most common way a buffalo lawn thins out. It's also the most shade-tolerant common Australian lawn, and shaded buffalo should sit toward the top of the range so it has enough leaf area to keep photosynthesising in lower light. Full detail on seasonal heights, feeding and common problems is in our buffalo grass care guide.

Kikuyu

Kikuyu is happiest at 25mm to 40mm, moving toward 40–50mm in hot, dry or part-shaded spots. It's the fastest-growing common Australian lawn grass, which is why it's usually the one that ends up mown weekly through spring and summer regardless of a fixed schedule — grow rate, not the calendar, decides the interval. Kikuyu also tolerates a once-off scalp to 10–15mm in late winter to clear old thatch and dead runners before spring growth kicks in, which is a deliberate exception to the usual rule rather than a height to hold year round. See our kikuyu grass care guide for the full seasonal breakdown.

Couch

Couch tolerates the lowest cut of any common Australian lawn grass, sitting comfortably at 10mm to 25mm through the growing season. Fine-leafed cultivars such as TifTuf and Santa Ana can handle the bottom of that range, while common couch grown from seed generally looks better a little higher. Let it run longer, toward 25–35mm, through winter dormancy and any prolonged dry spell — a low cut on stressed or dormant couch invites weeds and dieback rather than a neater look. Details on seasonal height and a spring renovation scalp are in our couch grass care guide.

Zoysia

Zoysia, most commonly sold in Australia as Empire, sits at 20mm to 35mm. It's a dense, slow-growing turf that copes well at the lower end of its range and needs mowing less often than buffalo, kikuyu or couch as a result — one of the reasons it's marketed as a low-maintenance option. Like buffalo, it's a runner grass, so avoid scalping it below its usual range for the same reason: exposed stolons recover slowly and open the door to weeds.

Tall fescue (cool-season)

Tall fescue is the outlier on this list — a cool-season, bunch-forming grass that's mown much taller than any warm-season lawn, typically 35mm to 75mm. Cutting it below about 35mm dries out the crown and thins the turf, since fescue relies on more leaf area to support itself than a runner grass does. Raise it toward the top of the range through summer, when it's working against its preferred cool conditions, and expect to mow it more often than buffalo — commonly every 10–14 days in active growth — since it doesn't slow down the same way warm-season grasses do once autumn arrives.

How height should shift with the seasons

Every grass type on this list benefits from a small seasonal adjustment rather than one fixed number all year:

• Spring: mow at the lower-to-middle end of the range as growth ramps up, and increase frequency rather than dropping the height further.
• Summer: raise the deck a notch, especially through heatwaves and dry spells — taller grass shades its own soil and root zone, cutting water loss and heat stress.
• Autumn: back toward the standard range as growth slows, with warm-season grasses easing off first and tall fescue staying active longest.
• Winter: sit at the higher end for warm-season lawns, which are close to dormant and slow to repair any damage; avoid scalping altogether until spring growth resumes.

For the full month-by-month version across mowing, feeding and weed timing, see our Victorian lawn care calendar.

What scalping actually does to a lawn

Scalping means cutting well below a grass type's minimum height, usually by dropping the deck low to "get ahead" on an overgrown lawn instead of mowing more often at the right height. The immediate effect is a lawn that looks brown or straw-coloured within a day or two, because the cut has exposed dead, tan-coloured stem material lower down the plant. Past the cosmetic hit, a scalped lawn is slower to recover, needs more frequent watering, and is more vulnerable to disease and weeds establishing in the thinned, sun-exposed soil. Runner grasses — buffalo, kikuyu, couch and zoysia — take the hardest hit, since scalping can cut directly into the stolons they spread from. The fix is patient, not complicated: raise the height back into the normal range and let the lawn thicken up over several mows rather than trying to fix it in one.

What happens if you let it grow too long

The other end of the mistake is just as common. Letting a lawn grow well past its target height, then cutting it back to the "right" number in one pass, breaks the one-third rule just as badly as a deliberate scalp — the plant loses the same proportion of leaf either way. An overgrown lawn also lays down thicker clippings, which smother the grass if left on the surface, and can trap enough moisture to encourage fungal disease in humid weather. If a lawn has already got away from you, step it down over two or three mows at the usual frequency, taking the top third each time, rather than one hard cut back to target height.

How to check and set your mower's cutting height

Most rotary mowers set height with a lever marked in unlabelled notches rather than millimetres, so it's worth checking the actual cut. Stand the mower on a flat, hard surface — a driveway or garage floor works well — and measure straight down to the cutting edge of the blade with a tape measure. That distance is the real cutting height. A few other things affect the result more than people expect:

• Sharp blades matter as much as the setting. A blunt blade tears rather than slices, leaving ragged, greyish tips that stress the plant regardless of the height number.
• Uneven ground changes the effective height. A mower set to 30mm will scalp high points and miss low points on a bumpy lawn — top-dressing significant dips helps more than any mower adjustment.
• Check after transport or storage. Height levers can shift if a mower's been knocked or stored on its side; measure before the first mow of a new season.

Not sure which grass you've got?

Guessing the wrong height for your actual grass type is one of the more common causes of a struggling lawn. Buffalo has broad, soft, blue-green blades and spreads via visible stolons; kikuyu and couch both have much finer blades and spread aggressively under fences and into garden beds, with kikuyu's blades slightly broader than couch's; zoysia sits between buffalo and couch in leaf width and feels dense and springy underfoot; tall fescue is coarser, clump-forming and doesn't spread by runners at all, and stays green through winter when the others brown off. If you're weighing up which grass suits your yard, our comparison of buffalo vs kikuyu vs couch and our guide to the best grass types for Melbourne and coastal Victoria cover sun, soil and salt tolerance for each.

Frequently asked questions

What happens if you cut your lawn too short?

Scalping exposes the crown of the plant — and in runner grasses like buffalo, the stolons — to direct sun and heat, which stresses the lawn and slows recovery. It browns off, thins out, needs more frequent watering, and gives weed seeds in the soil the sunlight they need to germinate.

Should I mow my lawn higher in summer?

Yes, for every grass type on this list. A slightly taller lawn shades its own root zone and soil, reducing water loss and heat stress during hot, dry stretches. Raise the mower a notch through peak summer and lower it again once the weather cools.

How do I find out what height my mower is set to?

Sit the mower on a flat, hard surface, then measure straight down from that surface to the cutting edge of the blade — that's the actual cutting height. Most mowers have a lever with numbered notches rather than a millimetre readout, so measuring directly is more reliable than trusting the notch number alone.

What height should I mow new turf at the first cut?

Let new turf establish before the first mow — most suppliers recommend waiting until it reaches roughly 60–70mm, then cutting back to around 50mm on a sharp blade. Mowing new turf too early or too short, before the roots have anchored, can lift whole pieces off the ground.

Does mowing height affect weeds in my lawn?

Yes, significantly. A taller, denser lawn shades the soil surface and crowds out weed seedlings before they establish, while a lawn mown too short lets sunlight reach weed seeds and opens bare patches for them to take hold. Bindii, clover and winter grass are all more likely to establish in a regularly scalped lawn.