Ecowitt WH51 Wireless Soil Moisture Sensor

Name: Ecowitt WH51 Wireless Soil Moisture Sensor
Brand: Ecowitt
Rating: 4.1 (1 reviews)

A cheap, accurate 868 MHz soil moisture sensor for pots and beds - but it is an accessory: readings need an Ecowitt gateway or console.

4.1 / 5

★★★★★ ★★★★★ Highly recommended

Strengths

Exceptional accuracy for the money - roughly +/-3% volumetric, far beyond gadget-grade moisture meters
Scales to 16 sensors on one gateway, making whole-balcony monitoring affordable
IP66 build lives outdoors permanently on a single AA

Watch outs

Useless on its own - the gateway requirement is the real entry cost and catches out first-time buyers
Ecowitt's sub-GHz radio locks you into its ecosystem rather than standard Zigbee/Thread
Readings take days to settle after insertion and benefit from per-soil calibration

Measurement Soil moisture 0-100% at 1% resolution, refreshed roughly every 70 seconds
Accuracy Around +/-3% volumetric in expert testing, after a settling-in period
Radio 868 MHz in the UK/Europe (915 MHz North America, 433 MHz elsewhere); range up to about 100 m open air
Gateway requirement Cannot be used alone - pairs with an Ecowitt Wi-Fi gateway (GW1200/GW2000/GW3000; legacy GW1100) or a compatible Ecowitt console/display

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By Rob Griffiths2 min read

Measurement: Soil moisture 0-100% at 1% resolution, refreshed roughly every 70 seconds
Accuracy: Around +/-3% volumetric in expert testing, after a settling-in period
Radio: 868 MHz in the UK/Europe (915 MHz North America, 433 MHz elsewhere); range up to about 100 m open air
Gateway requirement: Cannot be used alone - pairs with an Ecowitt Wi-Fi gateway (GW1200/GW2000/GW3000; legacy GW1100) or a compatible Ecowitt console/display
Sensors per gateway: Up to 16 WH51/WH51L sensors on one gateway, individually nameable
Calibration: Custom 0% and 100% AD calibration for different soil types
Power: 1x AA battery (not included)
Weatherproofing: IP66 - stays outdoors year-round
App and cloud: Free Ecowitt app/ecowitt.net dashboards with history and alerts via the gateway; no subscription
Variants: WH51L adds a 1 m corded probe (deeper soil) and an LCD; bundle kits (e.g. GW1206, GW3015, WH51+GW3000) include a gateway