Apollo PLT-1 Plant Sensor

Quick verdict

A simple, affordable plant sensor that does exactly what it should. It reports soil moisture, air temperature and humidity, and light (lux plus UV) to Home Assistant via ESPHome, with an optional waterproof soil-temperature probe. No cloud account, no subscription, no app. Stick it in the soil, connect it to WiFi, and build automations to alert you when your plants need water. At this price, you can put one in every pot without guilt.

Standout: Budget ESPHome plant sensor measuring soil moisture, air temperature and humidity, light (lux) and UV, plus an optional soil-temperature probe, fully local.

Notes last checked May 31, 2026.

Compatibility snapshot

Why it stands out

• measures soil moisture, air temperature and humidity, plus light (lux) and UV, with an optional waterproof soil-temperature probe
• ESPHome firmware is fully local and customizable
• budget-friendly price makes it practical to deploy one per plant or planter

Reasons to hesitate

• WiFi-based, so each sensor adds to your wireless network, which matters if you have many plants
• soil moisture probes can degrade over time with constant soil contact
• no built-in display, so you need Home Assistant or a dashboard to check readings

Best for

• Home Assistant users who want to automate plant watering based on actual soil moisture data
• plant enthusiasts who want local, no-cloud monitoring without Xiaomi or other cloud-dependent sensors

Avoid if

• you have dozens of plants. WiFi sensor density could become a problem
• you want a standalone plant monitor with its own app and display

Privacy and local-control notes

Fully local via ESPHome. No cloud, no account. Plant data stays on your network.

Home Assistant support: supported · integration path: ESPHome.

Built with ESPHome - see the ESPHome guide for Home Assistant →

Buying reality check

Price notes: Budget pricing makes it one of the most affordable local plant sensors available. Easy to justify buying multiples.

Compare side by side: see sensor comparisons →