Roborock RockMow Z120 LiDAR Robot Lawnmower

The one for a garden that isn't a rectangle.

Most robot mowers work brilliantly on a big open lawn and start guessing the moment they go in under a beech tree or down the side of the house. The Z120 is the answer to that. It navigates by LiDAR rather than by satellite, which means it does not care whether it can see the sky — and for a lot of Irish gardens, hemmed in by mature trees, hedging, sheds and gable walls, that is the difference between a machine that works and one that sulks in a corner.

It handles gardens up to 2,000 m², which is around half an acre, and there is not a metre of boundary wire to bury.

Why LiDAR, and why it matters in a garden like this

A spinning laser on top builds a live 3D picture of everything around it — the same approach a self-driving car uses — and a second system reads what its cameras see to double-check where it is. Between the two it knows its position to within a few centimetres, under canopy, between walls, and in the narrow bit down the side that every house seems to have.

The practical upshot: nothing gets mounted on your house. No antenna on the gable, no mast in the flowerbed, no cable run from the dock to a pole. You put the charging dock somewhere sensible with a socket, and that is the installation finished.

Setting it up

First time out, you walk it round the boundary once from your phone, or let it explore and map on its own. It learns the shape of the garden, remembers where the beds and the trampoline are, and from then on it works in tidy parallel lines rather than bouncing about at random. You can split the garden into as many as 15 separate zones and give each one its own schedule and cutting height — handy if the front lawn wants to look sharp and the orchard end can be left longer.

It looks before it goes

This is the bit people ask about first, usually because of a dog or a small child. It identifies obstacles and steers around them rather than nudging into them and reversing. Hedgehogs, which come out at dusk exactly when a mower is likely to be working, are the classic case — it goes around them. Lift it or tip it and it stops dead.

At 62 dB it runs at about the level of ordinary conversation — no louder than the neighbour's hedge trimmer and a world away from a petrol mower.

Through an Irish year

Four-wheel drive, and it will climb a slope of up to 80% — near enough 39 degrees, which is steeper than you would happily push a mower up. On soft, wet ground it keeps its footing where a two-wheel-drive machine would sit and spin, and there are rough-terrain wheels available if your ground is particularly heavy going.

It is rated IPX6 with rain and frost sensors, so when the weather turns it takes itself home to the dock and waits. Afterwards you can rinse it down with the hose. Come winter, bring it in, give it a clean and a charge, and it will be ready in March.

The numbers

• Covers up to 2,000 m² at 160 m² an hour
• Cuts 24 cm wide, 20–70 mm high, adjusted electrically from the app
• 6 Ah battery — about 110 minutes mowing, about 50 minutes to recharge
• Up to 15 zones, each with its own schedule
• WiFi, Bluetooth and 4G with three years included
• Alarm, live GPS, PIN lock and AirTag compatible
• 62 dB · IPX6 · 21.7 kg

What we do that a website cannot

We map your garden with you and set the first schedule before the machine leaves the shop, so you are not standing on the lawn in the drizzle reading a manual. After that you can ring us — you will get somebody who knows the machine and can usually sort it on the phone, and if it needs looking at, you bring it back here rather than posting it off to a service centre in another country.

Is the Z120 the right one for you?

If your garden is up to half an acre and has trees, walls or awkward corners in it, this is the one we would put you in. If it is bigger and more open, look at the Z130 — and if you are unsure, ring us with a rough size and a description of the layout and we will tell you straight. There is usually one running on the demo lawn if you would rather see it work first.