Garden water mist system

This blueprint implements a garden misting system that toggles on/off via a physical switch (corresponding to a water valve), and dynamically adjusts cycle duration and frequency based on temperature, relative humidity, and wind speed.

Open your Home Assistant instance and show the blueprint import dialog with a specific blueprint pre-filled.

https://gist.github.com/davefx/8c6bdaa124d932cade9acc0df71f1b60

Versions:

  • 1.0: Initial release
  • 1.1: Added factors to both timers. The cycle timer won’t depend on the wind speed, as wind is very variable.
  • 1.2: Changed formula for period between misting. Added two optional helpers to show timers.

Algorithm Description

When the user toggles the valve manually (via the physical or virtual switch), the system enters an “active” state. From then on, it starts a cycle of misting events that repeat periodically until the user disables it by toggling the switch again.

Valve open duration:
Base duration = 10 + (temperature - 25) * 2 - (humidity - 50) * 0.1

Adjusted for wind:

  • Wind > 20 km/h → skip misting (duration = 0)
  • Wind 10–20 km/h → reduced time: max(base * 0.5, 3)
  • Wind ≤ 10 km/h → full time: max(base, min_duration_open)

Cycle interval duration:

Base delay = 70 - (temperature - 25) * 2.5 + (humidity * 0.3)

Adjusted for wind:

  • Wind > 20 km/h → delay 9999s (effectively stops repeating)
  • Wind 10–20 km/h → max(base * 1.5, 60)
  • Wind ≤ 10 km/h → max(base, 30)

Here you can see a Youtube demo of the system in action.

1 Like

Hello David Marín,

Thanks for contributing to the community with a new Blueprint.

I have a suggestion for you. Many people who are not familiar with directory structures will have problems installing this without the Home Assistant MY tools.
Adding a MY link for this Blueprint to your top post would help them a lot.

Here is the link to make that.
Create a link – My Home Assistant