# How to cut long overgrown grass

Source: https://mowandedge.co.uk/blog/how-to-cut-long-grass
Published: 2026-10-12
Publisher: Mow and Edge

**In short:** Walk the area first to remove hidden objects and check for wildlife, then strim the long grass down to around 10 cm, working from the top down in layers. Rake off the cuttings, mow on the highest setting, and lower the height over several cuts a few days apart so the lawn is not scalped.

Long grass happens: after a holiday, a wet spring or when you take on a neglected garden. Running a mower straight into it usually ends with a stalled motor, a clogged deck and a scalped, yellow lawn. A strimmer, or a brush cutter for very rough ground, takes the height down first. This guide explains a safe, step by step approach that leaves the lawn in good shape.

## Check the area first

Long grass hides stones, toys, wire, glass and dog mess, all of which can damage a mower or be thrown by a strimmer. It can also shelter hedgehogs, frogs, toads and nesting birds. Walk slowly through the area and, where you can, cut from one side so wildlife can move away. Hedgehogs are especially at risk from strimmers in long grass.

Note: Wear eye protection, ear protection, gloves, long trousers and boots. Keep children and pets away while you cut.

## Choose the right tool

For grass up to knee height, a decent cordless strimmer copes if you work in layers. For very thick grass, nettles or brambles, a brush cutter with a blade is quicker and safer for the tool. A mower alone is only suitable once the grass is down to a manageable height.

| Grass | Best tool |
| --- | --- |
| Up to about 10 to 15 cm | Mower on its highest setting |
| Up to knee height | Strimmer, then mower |
| Dense, tall or weedy | Brush cutter or high voltage strimmer |
| Brambles and woody growth | Brush cutter with a blade |

Which tool for which grass

[Strimmer or brush cutter?](https://mowandedge.co.uk/blog/strimmer-vs-brush-cutter)

## Strim it down in layers

Do not try to cut long grass at ground level in one pass; it wraps round the head and overloads the motor. Cut the top third first, then the next, working down to around 10 cm.

1. Start at one edge and work across
2. Cut the top of the grass with the head held high
3. Sweep the head side to side, letting the line tip do the work
4. Lower the head and take the next layer
5. Stop when the grass is at about 10 cm
6. Clear grass wrapped round the shaft regularly, with the battery removed

## Rake off the cuttings

Long cuttings smother the lawn and turn it yellow. Rake them off and compost them. This also lets you see the ground before mowing, so you can spot anything the mower should avoid.

## Mow high, then lower in stages

Set the mower to its highest setting for the first cut and use the grass box rather than mulching, as long clippings will not mulch well. Leave a few days between cuts and lower the height a notch each time. This follows the one-third rule: remove no more than a third of the grass height in any one cut.

Our [one-third rule tool](https://mowandedge.co.uk/tools/one-third-rule) tells you how many cuts it will take to reach your target height. For mower choice, our guide to [cordless mowers for large gardens](https://mowandedge.co.uk/best/best-cordless-mower-for-large-garden) covers models with bigger batteries for heavy work.

## After care

The lawn may look pale for a week or two after its first cuts. Water in dry spells, avoid cutting too low and consider a light feed in spring or early autumn. Bare patches can be overseeded. If the lawn is very uneven, fill dips with top dressing in autumn.

## Keeping it under control

The easiest way to avoid long grass is to cut little and often during the growing season. If you are away often, a robot mower keeps grass short automatically. Our explainer on whether [robot mowers are worth it](https://mowandedge.co.uk/blog/are-robot-lawn-mowers-worth-it) covers the pros and cons.

## Common mistakes to avoid

The most common mistake is cutting too low too soon. Scalping long grass removes most of the leaf the plant needs to recover, leaving yellow or bare patches that weeds and moss soon fill. Taking it down gradually avoids this.

Another is cutting when the grass is wet. Wet long grass clogs the strimmer head and mower deck and is much harder work for a battery. Wait for a dry spell if you can. Finally, do not mulch long grass; the clippings are too long and heavy to break down and will smother the lawn.

If you need to clear a large area, have a second battery charged, or plan the job over two or three sessions. Cutting long grass drains batteries much faster than a normal weekly cut.

## Frequently asked questions

**Can a cordless mower cut long grass?** Only if it is not too long. Strim very long grass down first, then mow on the highest setting.

**What is the best strimmer for long grass?** A higher voltage strimmer with thicker line, or a brush cutter for very tough growth.

**Should I cut long grass all at once?** No. Take it down in stages over several cuts to avoid scalping the lawn.

**Is it safe to strim long grass with wildlife about?** Check the area carefully first and cut from one side, so animals can move away.

## Buying guides on this topic

- https://mowandedge.co.uk/best/best-cordless-strimmer
- https://mowandedge.co.uk/best/best-cordless-mower-for-large-garden
- https://mowandedge.co.uk/best/best-cordless-lawn-mower

## Sources

- [RHS: lawn care](https://www.rhs.org.uk/lawns)