Grow room control with Home Assistant - share your knowledge

Hello everybody!

In the last days and weeks, I was contacted several times about the possibilties Home Assistant could offer for people who want to grow their own weed at home. The starting point for these questions was the recent legalization of weed for recreational use/growth in Germany (1st of April 2024 - no april fools, it’s real). Right now, the growth of weed is legal in the three biggest markets for Home Assistant: Germany, the Netherlands and the United States.

So I thought, why not bring people together and open up a topic about all the things one should or could know, about using Home Assistant to monitor and control your grow room, tent or cabinet. This is not meant to be a thread where you talk about your highs or how much you harvested, it’s about the technical challenges and possibilities! If people would like to share their experiences, pitfalls and tricks, others might be able to avoid all the obstacles, that could come up or even help!

Legal notice - important, please read!

As in the above countries growing weed for recreational and personal use is legal, this topic is strictly limited to this! Here is no room for illegal commercial grows or mass production questions. If you have those, please look elsewhere for support, this topic is aimed strictly at people who want to grow weed for themselves!

That’s why it’s common in this area, to regulate such topics:

  • If your light uses more than 400W (combined, if more than one light) or you use additional CO₂, it will be deemed commercial growth and therefor won’t be tolerated in this topic!
  • If your question(s) point in the direction, that you’re doing this for your livelihood, the posts will be removed!
  • If you insist on bringing up illegal topics, your posts will be removed!
  • If growing weed is illegal in your country, please abide to your local laws! And don’t tell us about it. If we know, you’re doing something illegal, we need to remove your post(s). Don’t ask, don’t tell! :wink:

Let me make this crystal clear: this is a topic for the technical side of a grow-room! This is not a topic where you talk about how high you drove the night before (which btw is disgusting - don’t smoke and drive!)!

Legal things aside, let’s take a look at the fun side of a grow-room and how Home Assistant could help here.

I was made aware of a very cool configuration for ESPHome and an 8-channel-relay board, to monitor and control light, ventilation (inside and outside), temperature, humidity and tada by measuring the weight of the plant pots, the humidity inside your grow medium (soil, hydroponics, whatever). Sounds cool, doesn’t it? It is, trust me, I’ve seen it in action! Only problem, I couldn’t get hold of the author of this configuration, so we’ll have to wait, until I can ask for his permission. Stay tuned, I’m working on it! :slight_smile:

But there are a lot more things to discuss, so please get in and share your knowledge about how you automated your grow room! :slight_smile: All input is welcome and much appreciated!


Some threads to start:

SanLight controlled via ESP
This is a great post on how you can DIY the dimmer control of your SanLight with ESPHome.

Mars Hydro LED lights
Feature request to get control for Mars Hydro lights into core HA.

Growlight with PWM (Mars Hydro as well)
Using an ESP to control your grow light

More specifically, portions of the United States. Only 19 states allow growing it legally. Ironically, there are also 19 states where it is also still legal to marry your first cousin as well… soooooo, yeah.

But, I’m actually kind of interested to see where this goes as I have pitched to my company (an online nursery/plant seller) that we need more automation in our business and of course HA comes to mind as we have many grow rooms, greenhouses, etc that we BARELY track and monitor. While it’s not weed in particular, I think a lot of the same concepts carry over.

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