Maintenance Guide · Updated July 2026
UK Grass Cutting Height Chart: The Right Mowing Height
For most UK lawns the answer is 25-40 mm in summer, longer in shade and drought, and never removing more than a third of the blade in one cut. Here is the full chart and how to adjust it through the year.
The height chart
These figures reflect standard UK horticultural guidance (the kind the RHS and professional groundskeepers work to). Match the row to your lawn type, not to your neighbour's:
| Lawn type / situation | Recommended cutting height | Notes |
|---|---|---|
| General utility lawn (family lawn) | 25-40 mm in summer | The right range for most UK gardens - hard-wearing and healthy |
| Fine ornamental lawn | 12-25 mm | Only for fine fescue/bent lawns cut frequently - scalps ordinary rye lawns |
| Shaded areas | 40-50 mm | Longer blades capture more light where sun is limited |
| Drought / hot dry spells | Raise height (add roughly 10-20 mm) | Longer grass shades the soil and holds moisture |
| First cut of spring | Highest setting | A light topping only, then lower gradually over following weeks |
| Final cut of autumn | Slightly higher than summer (around 40 mm) | Extra length protects the grass through winter |
The golden rule: never cut more than a third
Whatever height you are aiming for, never remove more than one third of the grass blade in a single cut. Grass stores energy in its leaves; take too much at once and the plant diverts everything into regrowing leaf at the expense of its roots. The result is a shallow-rooted, stressed lawn that yellows in dry weather and lets weeds and moss move in.
So if your lawn has got away from you and stands at 90 mm, do not drop the mower to 30 mm and hack it down in one pass. Cut to 60 mm, wait three or four days, then cut again to 40 mm, and again if needed. It takes a week longer and the lawn will thank you for it.
Why height matters
Cutting height is the single biggest lever you have over lawn health, and it works in both directions:
- Too short: weak roots, moss, weeds, brown patches in summer, and a lawn that wears badly. Scalping is the most common lawn mistake in the UK.
- Too long: a soft, thatchy lawn that stays damp, invites fungal problems and looks untidy - though "too long" is far less damaging than "too short".
- Just right: dense growth that crowds out weeds, deeper roots, and better drought resistance.
Height only does its job if the blade is actually cutting rather than tearing. A dull blade shreds the grass tips, which then brown and let disease in. See our guide to sharpening your mower blade - once a year is the minimum.
Adjusting through the year
UK grass growth follows the temperature, so your cutting height and frequency should track the seasons rather than the calendar page:
- March: first cut on the highest setting once growth restarts. Light topping only.
- April: growth accelerates. Lower the height step by step towards your summer target, mowing weekly.
- May to June: peak growth. Hold your summer height (25-40 mm for a utility lawn) and mow weekly, or twice weekly on a fine lawn.
- July to August: watch the weather. In a dry spell, raise the height and mow less often; the lawn needs its length. Return to normal once rain resumes.
- September: growth picks up again after summer. Back to regular weekly mowing at summer height.
- October to November: raise the height slightly and stretch the interval as growth slows. The final cut, slightly higher than summer, usually lands in late October or November.
- December to February: mostly no mowing. In a mild winter a very light, high topping on a dry day is fine if the grass keeps growing - never mow frosted or waterlogged grass.
For the full month-by-month routine including feeding, scarifying and aeration, see our UK lawn care calendar.
Setting the height on your mower
Most rotary mowers adjust in steps rather than exact millimetres, usually via a single lever that moves all four wheels. Manufacturers label the settings differently, so check your manual for what each notch means in millimetres - the middle settings on most UK mowers correspond roughly to the 25-40 mm utility range. Cylinder mowers, common on fine lawns, adjust lower and more precisely. If your mower's lowest setting is 25 mm or more, that is deliberate: most rotary machines are not designed to cut ornamental-lawn short, and forcing it just scalps the high spots.
If you are choosing a new machine, height range is worth checking before you buy - our guides to cordless and electric mowers and petrol mowers list the cutting height ranges for each model.