Ckutassy is correct.
I have this moisture sensor connected to this controller and it works fine. I have this for watering my thuja hedges and it saves me a lot of effort and probably water.

You can connect the following sensor: https://www.gardena.com/ch-de...
On the back is the corresponding cable connection.
I operate this control without a sensor for parts of the garden.
Wireless only works with Gardena Smart Control, which I prefer.
The control from the mobile phone via app is great.