What Height to Mow: A UK Lawn Calendar by Month

The RHS rule of thumb: about 2.5 cm (1 in) in summer, about 4 cm (1.5 in) in spring, autumn and winter, and never remove more than a third of the grass height in one go.

The Calendar

Month	Height	How often	Robot mower notes
January–February	About 4 cm, if cut at all	Only in mild spells	Usually in storage. Do not mow frosty or waterlogged grass.
March	Highest setting for the first cut	Start as growth begins	Bring the mower out, fit new blades, start high.
April	Lower gradually towards 4 cm	Weekly to fortnightly	Increase mowing days as growth picks up.
May	About 4 cm	Weekly, or pause for No Mow May	Pause the schedule, or set a no-go zone for a wildflower patch.
June–August	About 2.5 cm; higher in drought	Weekly or more	In dry spells, raise the height and mow less.
September	Raise towards 4 cm	Weekly to fortnightly	Shorten schedules as growth slows and nights lengthen.
October	About 4 cm	Fortnightly, then stop	Last cuts. Prepare for winter storage.
November–December	About 4 cm, if cut at all	Only in mild spells	Mower stored; charging station left in place or brought in.

Heights and timings follow RHS guidance; robot mower notes are our practical summary. Fine ornamental lawns can be cut much lower, to 6–13 mm, but none of the robot mowers we track is rated to cut below 20 mm.

How Often to Mow

The RHS says lawns typically need mowing weekly or fortnightly from March to October. A robot mower goes further, cutting a little every day or two, so each cut removes only a few millimetres. That fits the RHS advice to take off no more than a third at a time, and the fine clippings fall back into the lawn rather than needing collecting.

In milder winters, the RHS says an occasional cut between late autumn and early spring can help. Most robot mower owners store theirs over winter instead.

Drought

In a dry summer, the RHS says to mow less often, raise the cutting height and leave short clippings as mulch. If growth stops, stop mowing. Established lawns usually green up again when rain returns, so there is no need to water them. On a robot mower, that means fewer mowing days and the height setting near the top of its range.

No Mow May

Plantlife's No Mow May asks gardeners to give the lawnmower May off, so wildflowers can bloom for pollinators. After that, it suggests cutting every 4–6 weeks for a shorter, re-flowering lawn, or just twice a year for a meadow. With a robot mower, the easy version is a no-go zone over one area of lawn. It also helps hedgehogs and other wildlife.

What Your Mower Can Set

Cutting height ranges vary a lot between models, and some brands do not publish them on their UK pages. Check the minimum and maximum before you buy if you want a very short or a long, shaggy lawn.

Cutting height ranges
Model	Cut height	Cut width
Segway Navimow X430	20–95 mm	430 mm
MOVA LiDAX Ultra 800	30–100 mm	200 mm
Ecovacs GOAT O1200 LiDAR Pro	30–80 mm	220 mm
eufy E15	25–75 mm	203 mm
Dreame A2	30–70 mm	Not stated
Mammotion LUBA 3 AWD 3000	25–70 mm	400 mm
Segway Navimow i205 AWD	20–60 mm	180 mm
Husqvarna Automower 310E NERA	20–55 mm	220 mm
Gardena SILENO minimo 500	20–45 mm	160 mm

Figures are from the manufacturer's UK page where published, otherwise from the retailer or source linked from the model name, checked 28 October 2026. "Not stated" means we found no published figure. Prices are the brand's UK price unless labelled otherwise, and retailers' prices change often.

Cutting in wet weather brings its own problems. See robot mowers in rain.

The Calendar

How Often to Mow

Drought

No Mow May

What Your Mower Can Set

Sources