This system reuses the hardware used in this project: https://hackaday.io/project/175937-the-ultimate-birdfeeder
Will switch back in the winter.
I also have a high volume watering system: https://hackaday.io/project/171942-two-zone-wifi-water-timer
Many NodeMCU projects save me $1,000+/year at home: https://sites.google.com/site/nodemcu12e/
I don't trust a soil moisture sensor and the amount of water involved is very small so it waters once/day.
Excess water just drains out the bottom of the pots located outside on the deck. Inside plants would be a different story.
I use a small self-priming pump external to the water supply. Same pump used in this project to refill the storage tank from the ground: https://hackaday.io/project/165664-zero-municipal-water-toilet
The pump only uses 0.5A at 12V so it's powered from a 2A 12V adapter.
With a filter it could be connected to a much larger rain barrel so the water supply would last much longer and use zero municipal water.
Outside electronics are inside a clear plastic tupperware container. The enclosure must be plastic because of the WiFi antenna on the NodeMCU. The small amount of heat from the devices stops condensation overnight. Temperature inside the box in the winter ice-free birdbath application is controlled using a digital temperature sensor and a 5 Watt 120V incandescent Christmas light as a heater. It also has house insulation around it inside a much larger box since it can get below -30C in the winter in my area. For that application 3 digital temperature sensors are used. All on one input defined as a OneWire bus. If I see condensation in the current arrangement I could program the light to maintain the interior of the box a few degrees above ambient.
All of my NodeMCUs include a DS3231 Real Time Clock. This keeps the time correct in spite of many power failures in my area. It's used to initiate tasks based on time of day as well as executing code only once per second without using delays. It's reset from the internet once/day early in the morning so it's very accurate and it's automatically corrected for daylight savings time or not.
All of the components are very inexpensive ordered on ebay. Long delivery though so I order more than I need usually.
Many zones could be created with separate pumps and tubing. Only one 12V power supply is needed if the zones are programmed to be on at different times.