Ecowitt WH51 Wireless Soil Moisture Sensor

The Ecowitt WH51 adds soil moisture monitoring to your Ecowitt WS3900 weather station, giving you a simple way to see how conditions are changing below the surface rather than relying on how the soil looks or feels from above.

Place the sensor in the soil and it measures moisture from 0–100%, transmitting an updated reading approximately every 70 seconds to the Ecowitt WS3900.

Your soil moisture data can then be viewed in the Ecowitt app and ecowitt.net, where you can follow current readings, look back at historical graphs and download your weather and soil-moisture records.

Know When the Soil Is Drying Out

The Ecowitt WH51 is useful anywhere you want a clearer picture of how quickly soil is gaining or losing moisture.

It can help you follow conditions in garden beds, lawns, vegetable gardens, greenhouses or other planted areas, making it easier to see the effect of rainfall and watering and how quickly the soil subsequently dries.

Rather than relying on a single reading, the real value comes from being able to follow the trend over time. Once you become familiar with the readings for your particular soil and plants, you can see much more clearly when conditions are becoming drier or how effectively watering has penetrated the soil.

View Soil Moisture in the Ecowitt App

The Ecowitt WH51 communicates wirelessly with the Ecowitt WS3900 console using a radio signal. The sensor itself does not need Wi-Fi or an internet connection.

The Ecowitt WS3900 then uploads the soil moisture data for viewing through the Ecowitt app and ecowitt.net.

You can see the current moisture reading, review historical graphs and download your recorded data without requiring a paid Ecowitt subscription.

Please note: Ecowitt WH51 soil moisture readings are not displayed directly on the Ecowitt WS3900 console screen. They are viewed through the Ecowitt app or ecowitt.net.

Monitor Multiple Areas

The Ecowitt WS3900 supports up to 16 shared WH51,and WH52 soil-sensor channels, allowing you to add additional sensors if you want to monitor several locations independently.

This can be particularly useful where different parts of a property dry at different rates or where plants have quite different watering requirements.

Each sensor can be identified separately within Ecowitt, making it easy to distinguish between the areas you are monitoring.

Simple Wireless Installation

The Ecowitt WH51 is battery powered and communicates wirelessly with the Ecowitt WS3900, so there is no cable required between the soil sensor and the house.

For the New Zealand/Oceania version, the Ecowitt WH51 operates on 433 MHz, with a specified wireless transmission distance of up to approximately 100 metres in open conditions.

The sensor uses one AA battery and transmits an updated soil-moisture reading approximately every 70 seconds.

When installing the sensor, loosen hard or compacted soil first and insert it vertically. Do not force or twist the probe into stones, roots or hard ground, as this can damage the sensor.

Why Choose the Ecowitt WH51?

• Monitor soil moisture directly — see how wet or dry the soil is rather than judging from the surface.
• Follow changes over time — use Ecowitt graphs to see the effects of rainfall, watering and drying.
• Wireless connection to the Ecowitt WS3900 — no cable is required between the soil sensor and console.
• View readings on your phone — access current and historical soil-moisture data through the Ecowitt app.
• Free historical records — review graphs and download your data through ecowitt.net without a paid Ecowitt subscription.
• Monitor several locations — add further compatible soil sensors if you want to compare different areas around your property.

FAQ’s

Can the Ecowitt WH51 operate on its own?

No. The Ecowitt WH51 is an accessory sensor and requires the Ecowitt WS3900 to receive its readings and upload them for viewing through the Ecowitt app or ecowitt.net.

The Ecowitt WH51 does not have its own display or Wi-Fi connection.

Does the Ecowitt WH51 measure soil temperature?

No. The Ecowitt WH51 measures soil moisture only.

If you want to monitor soil moisture, soil temperature and electrical conductivity (EC), the Ecowitt WH52 provides all three measurements.

Will the Ecowitt WH51 reading appear on the Ecowitt WS3900 display?

No. The Ecowitt WS3900 receives the Ecowitt WH51 data, but soil-moisture readings are uploaded for viewing through the Ecowitt app and ecowitt.net rather than displayed directly on the console.

Can I use more than one Ecowitt WH51?

Yes. The Ecowitt WS3900 supports up to 16 shared WH51 and WH52 soil-sensor channels, allowing separate sensors to monitor different areas.

Does the Ecowitt WH51 need Wi-Fi?

No. The Ecowitt WH51 sends its reading directly to the Ecowitt WS3900 using a wireless radio signal.

Your Ecowitt WS3900 uses your home Wi-Fi and internet connection when it uploads the soil-moisture information so you can view it in the Ecowitt app and ecowitt.net.

WH51 Manual