The short answer: every 7–10 days from October to April, and every 3–4 weeks from June to August. But frequency is only half the question, and it's the less important half.
The one-third rule
Never remove more than a third of the leaf blade in a single cut. That single rule sets your mowing interval for you — whatever period it takes your lawn to grow by 50% is your interval, and it changes through the season.
Break the rule and you scalp. Scalping removes the leaf the grass uses to photosynthesise, so the plant has to draw on root reserves to recover. Do it repeatedly and the root system shrinks, the lawn thins, and weeds move into the gaps. A lawn that gets cut hard once a month is almost always thinner than one cut lightly every week, even though it's had less total leaf removed.
Cutting heights by grass type
| Grass type | Summer height | Winter height |
|---|---|---|
| Kikuyu | 35–50mm | 25–35mm |
| Couch | 20–35mm | 15–25mm |
| Ryegrass / fescue blend | 40–55mm | 30–40mm |
| Fine fescue (shaded) | 50–60mm | 40–50mm |
| Newly laid ready lawn | 50mm+ for the first 6 weeks | — |
Why shade changes everything
Grass in shade has less light to work with, so it needs more leaf area to survive. Shaded areas should always be cut higher than the rest of the lawn — 50–60mm rather than 35mm — and mown less often. Cutting a shaded strip at the same height as a lawn in full sun is the fastest way to turn it into moss and bare dirt.
Wet grass, blunt blades, and the same direction every time
- Mowing wet grass tears rather than cuts, clumps the clippings, and compacts the soil under the wheels. Wait for the surface to dry if you can.
- A blunt blade shreds the leaf tip, which then browns off — that grey-brown cast over a freshly mown lawn is almost always blade sharpness, not disease. Sharpen every 20–25 hours of use.
- Vary your mowing direction between cuts. Always mowing the same way trains the grass to lie over and creates ruts along the wheel lines.
If keeping to a 7–10 day interval through an Auckland spring is unrealistic — and for most people it is — a regular mowing service on a fixed run day solves it. Greensward NZ mows across East, Central and South Auckland on set weekly and fortnightly runs.
Quick answers
How often should I mow my lawn in summer in Auckland?
Every 7–10 days from October through April. Auckland's growing season is long and kikuyu and couch lawns put on serious growth in that window — stretching past 10 days generally means breaking the one-third rule and scalping the lawn to get it back down.
How short should I cut my lawn?
Higher than most people think. Kikuyu suits 35–50mm in summer, a rye and fescue blend 40–55mm, and shaded areas 50–60mm. Raising the height going into summer shades the soil, holds moisture and keeps the lawn green weeks longer through a dry spell.
Is it bad to mow wet grass?
Yes. Wet grass tears instead of cutting cleanly, clippings clump and smother the lawn beneath them, and mower wheels compact saturated soil. Wait until the surface has dried where you can.