How FieldBonnet Works
Reliable technology that helps you understand exactly when your plants need water.
The Challenge of Plant Care
Every grower knows the struggle: Is the soil too dry? Did I water too much? The surface looks one way, but what's happening at root depth where it actually matters?
Without a way to measure what's happening in the soil, watering becomes guesswork. And guessing often leads to overwatering — the number one cause of plant loss.
FieldBonnet Reads What Your Soil Needs
FieldBonnet is a compact capacitive moisture sensor designed to sit in your soil at root depth. It measures moisture where it matters most — not at the surface where conditions change fastest.
Connected to your WiFi, it sends you email reports on soil conditions. Choose from 26 plant profiles with calibrated thresholds, or let it simply tell you when things are trending dry or holding wet.
Three Steps
Insert
Place FieldBonnet into your soil, positioning the probe near the root zone — about halfway between the stem and pot edge.
Connect
Hold the button for 3 seconds to activate the WiFi hotspot. Connect from your phone and walk through the setup wizard — no app needed.
Monitor
FieldBonnet takes readings on schedule and emails you when conditions change. Water when it says to, rest when it doesn't.
The Technology Inside
Capacitive Sensing
Unlike resistance probes that corrode over time, FieldBonnet uses 4-zone capacitive touch sensing for accurate, long-lasting readings.
Long Battery Life
Rechargeable via USB-C. One charge lasts 6-12 months with hourly deep-sleep readings.
WiFi Connected
ESP32-based WiFi connects to your network. Email notifications via SendGrid keep you informed without requiring an app.
Root-Level Accuracy
The probe measures moisture where roots actually absorb water, not just at the surface where soil dries fastest.
Understanding Soil Moisture
Soil moisture is the water held in the spaces between soil particles. Your plant's roots absorb this water along with dissolved nutrients. The challenge is finding the balance:
Too Dry
When soil becomes too dry, roots can't absorb water or nutrients. Plants wilt, leaves curl, and growth stops. Prolonged drought causes permanent damage to root systems.
On Track
Optimal moisture means roots have access to water while maintaining enough air pockets for oxygen. This is where your plant thrives — growing, producing new leaves, and staying healthy.
Too Wet
Overwatered soil becomes waterlogged. Roots can't get oxygen, leading to root rot. This is the most common cause of plant death, and it often happens gradually before symptoms appear above the soil line.
Why Overwatering Is So Common
We tend to show our plants care by watering them. But most plants prefer to dry out somewhat between waterings. By measuring actual moisture levels at root depth, FieldBonnet helps you resist the urge to overwater and water only when it matters.
Ready to Take the Guesswork Out?
Give your plants the honest information they need with FieldBonnet.
Shop FieldBonnet — $30