• Sensor
Apollo Automation

PLT-1 Ultimate Plant Sensor For Home Assistant

$27.99
$27.99
Shipping calculated at checkout.

The PLT-1B does not include a battery or charger due to shipping constraints. Users will need to source their own rechargeable 18650 for the battery version and a charger. Battery life is estimated at 6 months based on a quality rechargeable 18650 and the default sleep / wake settings.

The PLT-1 is an indoor plant multisensor that measures soil moisture, air temperature, humidity, LUX, and UV. It also features an onboard piezo buzzer and addressable RGB LED. Soil temperature can be measured using the optional temperature probe add-on. The sensor comes in a battery (B) and non-battery version, with the non-battery version being significantly smaller.

The PLT-1 uses a capacitive soil moisture sensor, which offers much better accuracy and durability compared to resistive sensors. Additionally, the ground contact portion is protected with a conformal coating, ensuring longevity and resistance to environmental factors.

Good sources for batteries:

USA: https://imrbatteries.com/products/samsung-35e-18650-3500mah-8a-battery
EU: https://www.nkon.nl/

Version:
  • Automated Watering: With its capacitive soil moisture sensor, you can set up automations to water plants only when moisture levels drop below a certain threshold.
  • Optimizing Sunlight Exposure: Use the LUX and UV sensors to monitor light levels, ensuring your plants get the right amount of sunlight. Automate window shades or grow lights based on current light conditions.
  • Temperature & Humidity Management: Track air temperature and humidity with the AHT20-F sensor, adjusting indoor climate controls (like fans, heaters, or humidifiers) to maintain ideal growing conditions.
  • Soil Temperature Monitoring: Use the optional waterproof soil temperature probe to monitor and control soil warmth for temperature-sensitive plants, especially in colder months.
  • Visual & Audio Alerts: The RGB LED can be programmed for visual notifications, such as turning red when soil is dry or green when conditions are optimal. The piezo buzzer can alert you if immediate action is needed.
  • Assembled sensor with case
  • A card with getting started instructions, including links to our documentation, open-source code, CAD models, and support
  • Apollo sticker

We hope to build a community on our Discord and continue delivering products the community wants. Our team will be there to help answer any questions, suggestions, or problems you might have.

Join our Discord.

Please see our Apollo Wiki for more information.

Product Details

  • Capacitive Soil Moisture Sensor with conformal coating: Accurate and durable, perfect for monitoring plant hydration.
  • AHT20-F Air Temperature & Humidity Sensor: Dust-protected for reliable air condition tracking.
  • LTR390 UV & LUX Sensor: Measures light and UV exposure, ensuring optimal lighting for plants.
  • Optional DS18B20 Waterproof Soil Temperature Probe: Monitors soil temperature with precision (20 cm / 7.8 inches).
  • RGB LED: Customizable for notifications (e.g., watering alerts, light levels).
  • Piezo Buzzer: Provides audible alerts for important plant care events.
  • Battery and Non-Battery Versions: Flexible power options to suit different setups and needs.
  • Home Assistant Integration: Easily automate and monitor plant health through your smart home system.
Related Products

You May Also Like

Customer Reviews

Based on 11 reviews
91%
(10)
0%
(0)
0%
(0)
9%
(1)
0%
(0)
100.0
100.0
J
Josh
Perfect

Arrived as expected and integrated directly into Home Assistant.

T
T.
Lots issues with the battery model

I purchased the battery model with a soil temp prob. The prob has to be plugged in prior to turning on the sensor, well with the battery version it is EXTREMELY difficult to get the sensor back in the case once the temp probe is attached. Also my temp and humidity readings on my device constantly stop being detected and show unknown. I have the sensor go to sleep for 1 hours and when it wakes up at least half the time the temp and humidity sensors are unknown the soil sensor is ALWAYS unknown. Lastly when I put the device to sleep it is impossible to wake the device up to do anything like update unless I disconnect the battery and reconnect it. If you have the ability to have a power cable next to your dice to plug in I'd say avoid the power version as it currently is. When the device is working it's amazing, but I won't be purchasing anymore until some of these bugs get worked out. I purchased this single one before getting one for every plant in the house.

Hi Travis,

Thank you for taking the time to share your experience. We’re sorry to hear the battery version of the PLT-1 has been challenging. While we continue to improve, here are some tips that may help:

- Soil Temperature Probe: Pressing the reset button after inserting the battery, closing the case, and plugging in the soil temp probe should have the same effect. You do not need to install the probe before re-assembly. Also, be sure that it is fully seated as we have seen that cause issues as well.

- Unknown Temp/Humidity Readings: This is a known issue that Trevor should have fixed in the latest firmware update. Please ensure you’re running the latest version.

- Update Intervals: Ensure that the temp/humidity and soil moisture update intervals are shorter than the sensor’s sleep cycle. Additionally, the awake time should be set for at least 60 seconds to allow all updates to complete.

-Waking the Device: You should not need to remove the battery to wake the device. We have a wiki article explaining how to wake up battery-powered sensors. (https://wiki.apolloautomation.com/products/general/battery-sensors/wake-up-battery-sensor/?h=wake)

Did you happen to reach out to our support team for help? We’re here to assist and make sure you’re satisfied. We appreciate your support and hope these tips make your experience better. Please let us know if there’s anything else we can do to help!

Best,
Justin Bunton
Co-Founder | Community Lead
Apollo Automation

A
A
Works like a charm!

Great web interface even when not connected to home assistant too!

S
Scott R.
No longer a plan murderer

I was once guilty of murder in the first degree. Yes, I’ve killed many plants—plantslaughter, if you will. But then I discovered the PLT-1 on the Smart Home Solver YouTube channel. Intrigued by Reed's glowing review, I decided to try one for myself, and everything he said was spot on.

The PLT-1 integrates seamlessly with Home Assistant, allowing me to create custom automations that remind me to water my plants. The built-in RGB LED is a lifesaver—it’s like my plants have their own status light! Beyond that, the wealth of telemetry provided by the device offers incredible insight into not just my plants’ needs but also the environmental conditions in my home.

I was so impressed with its performance that I ordered three more and now have them set up throughout my house. My plants are thriving, and I have peace of mind knowing I’ll never forget to care for them again. If you're a plant owner—especially a forgetful one—these devices are an absolute game-changer. Highly recommended!

B
Brent V.
Finally, a plant monitor that "just works"!

I've tried so many different plant monitor options over the years, I've lost count at this point. ALL of them were either "fiddly" in some form or other, or locked you into a proprietary ecosystem which would result in dependencies I couldn't live with.

This is the perfect balance between "plug and play" and true ownership of your own products/data.

Buy the USB powered version IMO - you can purchase a high quality "octopus" USB-C cable (I have some 1->4 units), a 2/3 port usbc wall plug, and power 8(+) monitors from a single outlet.

My one bit of feedback would be to allow these units to work in a hub/spoke method, where one could serve as a bluetooth proxy for the rest of them in order to limit the number of devices connected to your WiFi access points. If someone has 50 of these things, that's a lot if connection states to maintain... Especially when instead you could simply have 2-3 of them on your wifi and have the rest communicating through those 2-3 via bluetooth.

Can be done manually via espHome edits, but I'm too lazy at this point (... that'll probably change if ever it ends up becoming a problem I'm forced to address lol)

123