I just finished wiring the greenhouse attached to our office with my team. The setup was a raspberry pi zero w (which has built in wifi), a $5 sinodial valve, and some electrical wire.
The system required Tom to solder about 20 connections, and he rigged up the main electric to a simple relay. He also did irrigation with Nicole (thank you!). Travis connected in gpio, while we together troubleshoot issues software, operating system, and vnc client.