Short answer: In the growing season, mow about once a week (every 1–2 weeks for a general family lawn), and never cut off more than a third of the grass blade in one go. A typical family lawn is best kept around 2.5–4cm tall. Mow less often — or not at all — in drought and winter, and raise the blade in hot, dry weather.
The single most useful rule in lawn care is the one-third rule: removing more than a third of the leaf at once shocks the grass, weakens the roots and invites moss and weeds. Little and often always beats an occasional brutal scalp.
The one-third rule
Never remove more than one-third of the blade height in a single cut. So if you want to keep the lawn at 3cm, mow it before it reaches about 4.5cm. Cutting harder than that reduces the leaf area the grass needs for photosynthesis and stresses the plant — which shows up as browning and thinning.
Recommended cutting heights
| Lawn type | Cutting height |
|---|---|
| Fine / ornamental lawn | 6–13mm |
| General family lawn | 25–40mm |
| Shaded or hard-wearing lawn | 40mm or higher |
| First cut of spring / drought | Raise to the top of the range |
For most people, a general family lawn kept around 2.5–4cm is the sweet spot: it looks tidy, shades out weeds, and copes with wear and dry spells.
How often to mow through the year
- Spring (March–May): growth speeds up — from occasional cuts to about once a week. Start high and lower gradually.
- Summer (June–August): roughly weekly, but raise the blade in heat. Longer grass shades the soil and resists drought.
- Autumn (September–October): growth slows — drop back to every 1–2 weeks.
- Winter (November–February): usually none. Only top very lightly in a mild, dry spell, and never mow frosty or waterlogged grass.
See the full month-by-month lawn care calendar for how mowing fits with feeding and watering.
Adjust for weather, not just the date
Grass grows when it's warm and moist, and barely at all when it's dry or cold. In a heatwave, stop mowing or raise the height right up and leave the clippings to hold moisture. After rain returns and growth surges, you may need to cut more often for a while.
Rather than mowing on a fixed day, YardIQ tells you when the grass has actually grown enough to need cutting, based on your local weather.
A few habits that help
- Keep the blades sharp. Blunt blades tear the grass, leaving ragged, browning tips.
- Vary your direction. Mowing the same way every time can make grass lean and cause ruts.
- Mow dry grass where possible. Wet grass clumps, cuts unevenly and clogs the mower.
- Match height to your grass type. Not sure what you have? See how to identify your grass type.
Frequently asked questions
How short should I cut my lawn?
For a general family lawn, keep it around 2.5–4cm. Fine ornamental lawns can go shorter (down to about 6–13mm), while shaded or hard-wearing lawns do better kept at 40mm or more. Cutting too short weakens the grass and lets moss and weeds in.
What is the one-third rule for mowing?
Never remove more than one-third of the grass blade's height in a single cut. Taking off more shocks the grass and reduces the leaf it needs to grow. If the lawn has got long, lower it over several cuts rather than all at once.
How often should I mow my lawn in summer?
About once a week during active growth, but raise the cutting height in hot, dry weather so the longer grass shades the soil. In a drought it's fine to stop mowing altogether until rain returns.
Should I mow the lawn when it's wet?
It's best avoided. Wet grass clumps together, cuts unevenly, clogs the mower and can spread disease. Wait until the grass has dried where you can — and never mow frosty grass.