This is the first real decision you have to make, and the marketing is unhelpful about it. Wire-free is newer, so it gets sold as better. It isn’t better — it’s different, and it fails in different gardens.
How perimeter wire works
A low-voltage wire is pegged around the edge of your lawn and around anything you want the mower to avoid — ponds, flower beds, a tree with exposed roots. The mower senses the field around the wire and turns back when it reaches it. Within a few weeks the grass grows over the wire and you stop seeing it.
The good: it is completely reliable. It doesn’t care about tree cover, cloud, tall buildings or where the satellites are. It’s cheaper — usually £200–£400 less for a comparable machine. Once it’s in, it simply works, for years.
The bad: installation is an afternoon of work, on your knees, with a mallet. Changing your mind means lifting and relaying wire. And if you slice through it with a spade while planting, you have a fault to find.
How wire-free works
A small antenna somewhere on your property receives satellite positioning and corrects it to centimetre accuracy — this is what RTK means. You walk the perimeter once holding the mower or your phone, and it stores the shape of your garden as a map.
The good: setup is under an hour and involves no digging. You can redraw zones whenever you like from your phone. Because it knows where it is, it mows in neat parallel lines rather than bouncing around at random, which looks better and covers the lawn faster.
The bad: it needs a reasonably clear view of the sky. Dense tree canopy over the whole lawn, or a small garden hemmed in by tall buildings, can degrade positioning. It also costs more.
So which one?
- Heavy tree cover over most of the lawn — choose wire. This is not a close call.
- Small garden surrounded by tall buildings — choose wire.
- You expect to change the garden layout — choose wire-free.
- Several separate lawn areas — wire-free is much easier to manage.
- Budget is the deciding factor — wire, comfortably. You are not getting a worse cut.
- Open lawn, and you’d rather not spend an afternoon pegging cable — wire-free.
Still torn? Tell us about your garden and we’ll give you a straight answer.