Garage wall is starting to mold

Keeping doors regularly in the ventilation position is simply a must in autumn/winter.

Or paint with lime paint, nothing grows on it. :D

Or paint with lime paint, nothing grows on it. :D

Then something else rots away. The moisture has to go somewhere. With us, the moisture settles on 3 portholes…

Ventilation on and done. Or just ventilate manually regularly.

Then something else rots away. The moisture has to go somewhere. In our case, the moisture settles on 3 portholes…

Well, the question is what is stored in the garage. If it is only the car and bicycles and trash cans, then it is enough if the wall is painted in such a way that the paint does not provide a base for mold. Garages, if they are not built and heated like living spaces, are always rather damp in corresponding weather conditions; therefore, paint on which no mold can grow is appropriate. Mold grows at 45% relative humidity and above. If the walls are not blocked by items, then that is usually not a problem in the garage.

Mold grows at 45% RH.

That seems very low to me. Then we would all already have a mold problem. The first sources I could find talk about 65 to 70% RH.