How to Audit Your Garden Before Buying a Wire-Free Robot Mower

Before looking at a spec sheet, measure. That is the rule that mower retailers never emphasise. A perfect RTK model in an open garden becomes useless in an enclosed one. An excellent standard model on flat ground damages its blades on a 30% slope. Four variables are enough to determine 90% of your choice.

Variable 1: Sky Coverage

The first measurement to make is not your lawn area. It is sky visibility.

Stand in the centre of your lawn and look up. Estimate the percentage of sky that is visible and unobstructed by walls, rooflines, trees, or structures. If that percentage is above 60%, an RTK model will work correctly. Below 60%, GNSS signal will be too degraded for accurate navigation, and you need a LiDAR or Vision model.

Town house gardens with walls on three sides typically have sky coverage of 30 to 50%. Gardens with a large central tree or tall hedges can drop to 40%. For these configurations: LiDAR.

A garden containing a glass greenhouse, even partially: Vision. LiDAR beams pass through glass and fail to detect it, creating a blind spot in the garden map.

Variable 2: Maximum Slope

Measure your steepest slope with a free inclinometer app on your smartphone (available on iOS and Android, accuracy is more than sufficient for this decision). The measurement takes under two minutes.

Results and implications:

• Slope up to 25%: all two-wheel-drive models work
• Slope between 25% and 35%: check the exact specification of the model you are considering
• Slope above 35%: AWD is required

A two-wheel-drive model on a 30% slope will not fall over, but it will lose traction on wet ground, leave ruts on soft soil, and increase blade wear by 40% compared to flat-ground operation. The damage to the lawn over a full season is real.

Variable 3: Actual Lawn Area

The total garden size is not the lawn area. Calculate only the effective grass surface: subtract paths, terraces, beds, vegetable patches, pools, and greenhouse footprints.

A 400 m² garden can have only 180 m² of actual grass if a large portion is landscaped. This figure directly determines the capacity category of the robot you need (500 m², 1000 m², 2000 m²).

Buying a robot rated for 1000 m² when you have 180 m² of grass is not a functional problem, but it is unnecessary overcapacity. Buying a model rated for 300 m² when you have 350 m² is an error that will show up as incomplete sessions from the first few weeks of use.

Variable 4: Obstacles and Perimeter Complexity

Count permanent obstacles within the mowing zone: trees, shrub islands, water features, compost bins. Then measure the narrowest passage between any two grass zones.

A passage under 60 cm is problematic for most wire-free robots. Some compact models (Segway Navimow i105E, Worx Landroid Vision M800) can pass through 50 cm corridors, but that is a hard limit.

For gardens with many closely spaced obstacles: Vision, for real-time detection and routing. For gardens with a complex perimeter but few internal obstacles: LiDAR is sufficient.

Decision Matrix

| Configuration | Recommended technology | Example model |
|---|---|---|
| Open sky, slope < 25%, simple garden | RTK / GNSS | Segway Navimow i105E |
| Limited sky (walls, trees), slope < 25% | LiDAR | Mammotion Luba Mini AWD 1500 |
| Garden with pets or dynamic obstacles | Vision | Dreame A3 AWD Pro 3500 |
| Open sky, slope > 35% | RTK + AWD | Mammotion Luba 2 AWD 5000 |
| Glass greenhouse + multiple obstacles | Vision + AWD | Dreame A3 AWD Pro 3500 |