How often should I water

I have a nice rosemary bush in a large container which has been doing very well through the summer. Just before the snow came I moved it further back on my patio to a more sheltered part and put some bubble rap over the top with a small hole in the top for air. My question is how often should I water this if at all.
Also I have two Lavender plants in containers which I have given the same treatment the same question for these as well.

 

I have numerous container plants some protected some not ..
In general all I do is wait for a mild spell in the weather, and then early in the day (this allows the surface and any splashes to dry off ) give them a reasonable amount of water depending on the size of the plants .You only need enough to stop them drying out to much ..and it will the plantsthat are packed with roots that dry out most ..
Another point to remember, in really bad weather is that the plant rootball can freeze through the pot so it is advisable to wrap pots as well ,particuarly if they are thin plastic type .

Dave